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commit 90b8596ac46043e4a782d9111f5b285251b13756 upstream.
Hans de Goede reported Bluetooth adapters (HCIs) connected over an UART
connection failed due corrupted Rx payload. The problem was narrowed
down to DMA Rx starting on UART_IIR_THRI interrupt. The problem occurs
despite LSR having DR bit set, which is precondition for attempting to
start DMA Rx in the first place.
From a debug patch:
[x.807834] 8250irq: iir=cc lsr+saved=60 received=0/15 ier=0f dma_t/rx/err=0/0/0
[x.808676] 8250irq: iir=c2 lsr+saved=61 received=0/0 ier=0f dma_t/rx/err=0/0/0
[x.808776] 8250irq: iir=cc lsr+saved=60 received=1/12 ier=0d dma_t/rx/err=0/1/0
[x.808870] Bluetooth: hci0: Frame reassembly failed (-84)
In the debug snippet, received field indicates 1 byte was transferred
over DMA and 12 bytes after that with the non-DMA Rx. The sole byte DMA
handled was corrupted (gets zeroed) which leads to the HCI failure.
This problem became apparent after commit e8ffbb71f783 ("serial: 8250:
use THRE & __stop_tx also with DMA") changed Tx stop behavior. Tx stop
is now triggered from a THRI interrupt.
Despite that this problem looks like a HW bug, this fix is not adding
UART_BUG_xx flag to the driver beucase it seems useful in general to
avoid starting DMA when there are only a few bytes to transfer.
Skipping DMA for small transfers avoids the extra overhead DMA incurs.
Thus, don't setup DMA Rx on UART_IIR_THRI but leave it to a subsequent
interrupt which has Rx a related IIR value.
By returning false from handle_rx_dma(), the DMA vs non-DMA decision is
postponed until either UART_IIR_RDI (FIFO threshold worth of bytes
awaiting) or UART_IIR_TIMEOUT (inter-character timeout) triggers at a
later time which allows better to discern whether the number of bytes
warrants starting DMA or not.
Reported-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Fixes: e8ffbb71f783 ("serial: 8250: use THRE & __stop_tx also with DMA")
Cc: stable@vger.kernel.org
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230317103034.12881-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 178e00f36f934a88682d96aa046c1f90cb6f83a7 upstream.
For serdev framework, tty->dev is a NULL pointer, lpuart_uport_is_active
calling device_may_wakeup() may cause kernel NULL pointer crash, so here
add the NULL pointer check before using it.
Fixes: 4f5cb8c5e915 ("tty: serial: fsl_lpuart: enable wakeup source for lpuart")
Cc: stable <stable@kernel.org>
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20230323110923.24581-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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UARTCTRL_SBK is asserted in lpuart32_tx_empty
commit 9425914f3de6febbd6250395f56c8279676d9c3c upstream.
According to LPUART RM, Transmission Complete Flag becomes 0 if queuing
a break character by writing 1 to CTRL[SBK], so here need to avoid
checking for transmission complete when UARTCTRL_SBK is asserted,
otherwise the lpuart32_tx_empty may never get TIOCSER_TEMT.
Commit 2411fd94ceaa("tty: serial: fsl_lpuart: skip waiting for
transmission complete when UARTCTRL_SBK is asserted") only fix it in
lpuart32_set_termios(), here also fix it in lpuart32_tx_empty().
Fixes: 380c966c093e ("tty: serial: fsl_lpuart: add 32-bit register interface support")
Cc: stable <stable@kernel.org>
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20230323054415.20363-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit f92ed0cd9328aed918ebb0ebb64d259eccbcc6e7 upstream.
SCI IP on RZ/G2L alike SoCs do not need regshift compared to other SCI
IPs on the SH platform. Currently, it does regshift and configuring Rx
wrongly. Drop adding regshift for RZ/G2L alike SoCs.
Fixes: dfc80387aefb ("serial: sh-sci: Compute the regshift value for SCI ports")
Cc: stable@vger.kernel.org
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230321114753.75038-3-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit b43a18647f03c87e77d50d6fe74904b61b96323e upstream.
The fourth interrupt on SCI port is transmit end interrupt compared to
the break interrupt on other port types. So, shuffle the interrupts to fix
the transmit end interrupt handler.
Fixes: e1d0be616186 ("sh-sci: Add h8300 SCI")
Cc: stable <stable@kernel.org>
Suggested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230317150403.154094-1-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit f8086d1a65ac693e3fd863128352b4b11ee7324d upstream.
REGMAP is a hidden (not user visible) symbol. Users cannot set it
directly thru "make *config", so drivers should select it instead of
depending on it if they need it.
Consistently using "select" or "depends on" can also help reduce
Kconfig circular dependency issues.
Therefore, change the use of "depends on REGMAP" to "select REGMAP".
Fixes: 8d310c9107a2 ("drivers/tty/serial/8250: Make Aspeed VUART SIRQ polarity configurable")
Cc: stable <stable@kernel.org>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Oskar Senft <osk@google.com>
Cc: linux-serial@vger.kernel.org
Link: https://lore.kernel.org/r/20230226053953.4681-9-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 6e01f9a594ee0f69fb52cc8d11971612b4817f0b upstream.
The 8250 handle_irq callback is not just called from the interrupt
handler but also from a timer callback when polling (e.g. for ports
without an interrupt line). Consequently the callback must explicitly
disable interrupts to avoid a potential deadlock with another interrupt
in polled mode.
Fix up the two paths in the freescale callback that failed to re-enable
interrupts when polling.
Fixes: 853a9ae29e97 ("serial: 8250: fix handle_irq locking")
Cc: stable@vger.kernel.org # 5.13
Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/r/Y/xYzqp4ogmOF5t0@kili
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230227085046.24282-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 32e293be736b853f168cd065d9cbc1b0c69f545d upstream.
As per HW manual for EMEV2 "R19UH0040EJ0400 Rev.4.00", the UART
IP found on EMMA mobile SoC is Register-compatible with the
general-purpose 16750 UART chip. Fix UART port type as 16750 and
enable 64-bytes fifo support.
Fixes: 22886ee96895 ("serial8250-em: Emma Mobile UART driver V2")
Cc: stable@vger.kernel.org
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230227114152.22265-2-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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UARTCTRL_SBK is asserted
commit 2411fd94ceaa6e11326e95d6ebf876cbfed28d23 upstream.
According to LPUART RM, Transmission Complete Flag becomes 0 if queuing
a break character by writing 1 to CTRL[SBK], so here need to skip
waiting for transmission complete when UARTCTRL_SBK is asserted,
otherwise the kernel may stuck here.
And actually set_termios() adds transmission completion waiting to avoid
data loss or data breakage when changing the baud rate, but we don't
need to worry about this when queuing break characters.
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/20230223093941.31790-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 1be6f2b15f902c02e055ae0b419ca789200473c9 upstream.
From time to time DMA completion can come in the middle of DMA shutdown:
<process ctx>: <IRQ>:
lpuart32_shutdown()
lpuart_dma_shutdown()
del_timer_sync()
lpuart_dma_rx_complete()
lpuart_copy_rx_to_tty()
mod_timer()
lpuart_dma_rx_free()
When the timer fires a bit later, sport->dma_rx_desc is NULL:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000004
pc : lpuart_copy_rx_to_tty+0xcc/0x5bc
lr : lpuart_timer_func+0x1c/0x2c
Call trace:
lpuart_copy_rx_to_tty
lpuart_timer_func
call_timer_fn
__run_timers.part.0
run_timer_softirq
__do_softirq
__irq_exit_rcu
irq_exit
handle_domain_irq
gic_handle_irq
call_on_irq_stack
do_interrupt_handler
...
To fix this fold del_timer_sync() into lpuart_dma_rx_free() after
dmaengine_terminate_sync() to make sure timer will not be re-started in
lpuart_copy_rx_to_tty() <= lpuart_dma_rx_complete().
Fixes: 4a8588a1cf86 ("serial: fsl_lpuart: delete timer on shutdown")
Cc: stable <stable@kernel.org>
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Link: https://lore.kernel.org/r/20230309134302.74940-2-alexander.sverdlin@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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dependency"
commit 2d638be71155b2e036aca1966b6129e2d661e91f upstream.
This reverts commit 5779a072c248db7a40cfd0f5ea958097fd1d9a30.
This results in a link error of
ld: drivers/tty/serial/earlycon.o: in function `parse_options':
drivers/tty/serial/earlycon.c:99: undefined reference to `uart_parse_earlycon'
When the config is in this state
CONFIG_SERIAL_CORE=m
CONFIG_SERIAL_CORE_CONSOLE=y
CONFIG_SERIAL_EARLYCON=y
CONFIG_SERIAL_FSL_LPUART=m
CONFIG_SERIAL_FSL_LPUART_CONSOLE=y
Fixes: 5779a072c248 ("tty: serial: fsl_lpuart: adjust SERIAL_FSL_LPUART_CONSOLE config dependency")
Cc: stable <stable@kernel.org>
Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230226173846.236691-1-trix@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 04a189c720aa2b6091442113ce9b9bc93552dff8 ]
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
Cc: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230202141221.2293012-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit c8f71b49ee4d28930c4a6798d1969fa91dc4ef3e ]
The GPIO controller component of the sc16is7xx driver is setup too
early, which can result in a race condition where another device tries
to utilise the GPIO lines before the sc16is7xx device has finished
initialising.
This issue manifests itself as an Oops when the GPIO lines are configured:
Unable to handle kernel read from unreadable memory at virtual address
...
pc : sc16is7xx_gpio_direction_output+0x68/0x108 [sc16is7xx]
lr : sc16is7xx_gpio_direction_output+0x4c/0x108 [sc16is7xx]
...
Call trace:
sc16is7xx_gpio_direction_output+0x68/0x108 [sc16is7xx]
gpiod_direction_output_raw_commit+0x64/0x318
gpiod_direction_output+0xb0/0x170
create_gpio_led+0xec/0x198
gpio_led_probe+0x16c/0x4f0
platform_drv_probe+0x5c/0xb0
really_probe+0xe8/0x448
driver_probe_device+0xe8/0x138
__device_attach_driver+0x94/0x118
bus_for_each_drv+0x8c/0xe0
__device_attach+0x100/0x1b8
device_initial_probe+0x28/0x38
bus_probe_device+0xa4/0xb0
deferred_probe_work_func+0x90/0xe0
process_one_work+0x1c4/0x480
worker_thread+0x54/0x430
kthread+0x138/0x150
ret_from_fork+0x10/0x1c
This patch moves the setup of the GPIO controller functions to later in the
probe function, ensuring the sc16is7xx device has already finished
initialising by the time other devices try to make use of the GPIO lines.
The error handling has also been reordered to reflect the new
initialisation order.
Co-developed-by: Wen-chien Jesse Sung <jesse.sung@canonical.com>
Signed-off-by: Wen-chien Jesse Sung <jesse.sung@canonical.com>
Signed-off-by: Isaac True <isaac.true@canonical.com>
Link: https://lore.kernel.org/r/20221130105529.698385-1-isaac.true@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit c4c81db5cf8bc53d6160c3abf26d382c841aa434 ]
LPUART IP has a bug that it treats the CTS as higher priority than the
break signal, which cause the break signal sending through UARTCTRL_SBK
may impacted by the CTS input if the HW flow control is enabled.
Add this workaround patch to fix the IP bug, we can disable CTS before
asserting SBK to avoid any interference from CTS, and re-enable it when
break off.
Such as for the bluetooth chip power save feature, host can let the BT
chip get into sleep state by sending a UART break signal, and wake it up
by turning off the UART break. If the BT chip enters the sleep mode
successfully, it will pull up the CTS line, if the BT chip is woken up,
it will pull down the CTS line. If without this workaround patch, the
UART TX pin cannot send the break signal successfully as it affected by
the BT CTS pin. After adding this patch, the BT power save feature can
work well.
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20221214031137.28815-2-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit ef25e16ea9674b713a68c3bda821556ce9901254 ]
There maybe pending USR interrupt before requesting irq, however
uart_add_one_port has not executed, so there will be kernel panic:
[ 0.795668] Unable to handle kernel NULL pointer dereference at virtual addre
ss 0000000000000080
[ 0.802701] Mem abort info:
[ 0.805367] ESR = 0x0000000096000004
[ 0.808950] EC = 0x25: DABT (current EL), IL = 32 bits
[ 0.814033] SET = 0, FnV = 0
[ 0.816950] EA = 0, S1PTW = 0
[ 0.819950] FSC = 0x04: level 0 translation fault
[ 0.824617] Data abort info:
[ 0.827367] ISV = 0, ISS = 0x00000004
[ 0.831033] CM = 0, WnR = 0
[ 0.833866] [0000000000000080] user address but active_mm is swapper
[ 0.839951] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
[ 0.845953] Modules linked in:
[ 0.848869] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.1.1+g56321e101aca #1
[ 0.855617] Hardware name: Freescale i.MX8MP EVK (DT)
[ 0.860452] pstate: 000000c5 (nzcv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 0.867117] pc : __imx_uart_rxint.constprop.0+0x11c/0x2c0
[ 0.872283] lr : imx_uart_int+0xf8/0x1ec
The issue only happends in the inmate linux when Jailhouse hypervisor
enabled. The test procedure is:
while true; do
jailhouse enable imx8mp.cell
jailhouse cell linux xxxx
sleep 10
jailhouse cell destroy 1
jailhouse disable
sleep 5
done
And during the upper test, press keys to the 2nd linux console.
When `jailhouse cell destroy 1`, the 2nd linux has no chance to put
the uart to a quiese state, so USR1/2 may has pending interrupts. Then
when `jailhosue cell linux xx` to start 2nd linux again, the issue
trigger.
In order to disable irqs before requesting them, both UCR1 and UCR2 irqs
should be disabled, so here fix that, disable the Ageing Timer interrupt
in UCR2 as UCR1 does.
Fixes: 8a61f0c70ae6 ("serial: imx: Disable irqs before requesting them")
Suggested-by: Sherry Sun <sherry.sun@nxp.com>
Reviewed-by: Sherry Sun <sherry.sun@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Acked-by: Jason Liu <jason.hui.liu@nxp.com>
Link: https://lore.kernel.org/r/20230206013016.29352-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 3957b9501a5a8fa709ae4a47483714491471f6db ]
The previous 'commit 846651eca073 ("serial: fsl_lpuart: RS485 RTS
polariy is inverse")' only fixed the inverse issue on lpuart 8bit
platforms.
This is a follow-up patch to fix the RS485 polarity inverse
issue on lpuart 32bit platforms.
Fixes: 03895cf41d18 ("tty: serial: fsl_lpuart: Add support for RS-485")
Reported-by: Sherry Sun <sherry.sun@nxp.com>
Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com>
Link: https://lore.kernel.org/r/20230207162420.3647904-1-shenwei.wang@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 9ad9df8447547febe9dd09b040f4528a09e495f0 ]
The RXWATER value must be greater than 0 according to the LPUART
reference manual. And when the number of datawords in the receive
FIFO is greater than RXWATER, an interrupt or a DMA request is
generated, so no need to set the different value for lpuart interrupt
case and dma case. Here delete the wrong RXWATER setting for dma case
directly.
Fixes: 42b68768e51b ("serial: fsl_lpuart: DMA support for 32-bit variant")
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20230130064449.9564-4-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 38f28cfe9d08e3a47ef008798b275fef8118fc20 ]
Add the missing clk_disable_unprepare() before return from
tegra_uart_hw_init() in the error handling path.
When request_irq() fails in tegra_uart_startup(), 'tup->uart_clk'
has been enabled, fix it by adding clk_disable_unprepare().
Fixes: cc9ca4d95846 ("serial: tegra: Only print FIFO error message when an error occurs")
Fixes: d781ec21bae6 ("serial: tegra: report clk rate errors")
Signed-off-by: Yi Yang <yiyang13@huawei.com>
Link: https://lore.kernel.org/r/20221126020852.113378-1-yiyang13@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 4029dfc034febb54f6dd8ea83568accc943bc088 ]
The LPUART Status Register needs to be cleared when closing the uart
port to get a clean environment when reopening the uart.
Fixes: 380c966c093e ("tty: serial: fsl_lpuart: add 32-bit register interface support")
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20221125101953.18753-4-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 1d4bd0e4ae4ba95892bef919a8d4d3f08f122d7e ]
UARTBAUD_RDMAE and UARTBAUD_TDMAE are enabled in lpuart32_startup(), but
lpuart32_shutdown() not disable them, only free the dma ring buffer and
release the dma channels, so here disable the Rx/Tx DMA first in
lpuart32_shutdown().
Fixes: 42b68768e51b ("serial: fsl_lpuart: DMA support for 32-bit variant")
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20221125101953.18753-3-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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As DMA Rx can be completed from two places, it is possible that DMA Rx
completes before DMA completion callback had a chance to complete it.
Once the previous DMA Rx has been completed, a new one can be started
on the next UART interrupt. The following race is possible
(uart_unlock_and_check_sysrq_irqrestore() replaced with
spin_unlock_irqrestore() for simplicity/clarity):
CPU0 CPU1
dma_rx_complete()
serial8250_handle_irq()
spin_lock_irqsave(&port->lock)
handle_rx_dma()
serial8250_rx_dma_flush()
__dma_rx_complete()
dma->rx_running = 0
// Complete DMA Rx
spin_unlock_irqrestore(&port->lock)
serial8250_handle_irq()
spin_lock_irqsave(&port->lock)
handle_rx_dma()
serial8250_rx_dma()
dma->rx_running = 1
// Setup a new DMA Rx
spin_unlock_irqrestore(&port->lock)
spin_lock_irqsave(&port->lock)
// sees dma->rx_running = 1
__dma_rx_complete()
dma->rx_running = 0
// Incorrectly complete
// running DMA Rx
This race seems somewhat theoretical to occur for real but handle it
correctly regardless. Check what is the DMA status before complething
anything in __dma_rx_complete().
Reported-by: Gilles BULOZ <gilles.buloz@kontron.com>
Tested-by: Gilles BULOZ <gilles.buloz@kontron.com>
Fixes: 9ee4b83e51f7 ("serial: 8250: Add support for dmaengine")
Cc: stable@vger.kernel.org
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230130114841.25749-3-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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__dma_rx_complete() is called from two places:
- Through the DMA completion callback dma_rx_complete()
- From serial8250_rx_dma_flush() after IIR_RLSI or IIR_RX_TIMEOUT
The former does not hold port's lock during __dma_rx_complete() which
allows these two to race and potentially insert the same data twice.
Extend port's lock coverage in dma_rx_complete() to prevent the race
and check if the DMA Rx is still pending completion before calling
into __dma_rx_complete().
Reported-by: Gilles BULOZ <gilles.buloz@kontron.com>
Tested-by: Gilles BULOZ <gilles.buloz@kontron.com>
Fixes: 9ee4b83e51f7 ("serial: 8250: Add support for dmaengine")
Cc: stable@vger.kernel.org
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230130114841.25749-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Requesting an interrupt with IRQF_ONESHOT will run the primary handler
in the hard-IRQ context even in the force-threaded mode. The
force-threaded mode is used by PREEMPT_RT in order to avoid acquiring
sleeping locks (spinlock_t) in hard-IRQ context. This combination
makes it impossible and leads to "sleeping while atomic" warnings.
Use one interrupt handler for both handlers (primary and secondary)
and drop the IRQF_ONESHOT flag which is not needed.
Fixes: e359b4411c283 ("serial: stm32: fix threaded interrupt handling")
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Valentin Caron <valentin.caron@foss.st.com> # V3
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230120160332.57930-1-marex@denx.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial driver fixes from Greg KH:
"Here are some small tty and serial driver fixes for 6.2-rc5 that
resolve a number of tiny reported issues and some new device ids. They
include:
- new device id for the exar serial driver
- speakup tty driver bugfix
- atmel serial driver baudrate fixup
- stm32 serial driver bugfix and then revert as the bugfix broke the
build. That will come back in a later pull request once it is all
worked out properly.
- amba-pl011 serial driver rs486 mode bugfix
- qcom_geni serial driver bugfix
Most of these have been in linux-next with no reported problems (well,
other than the build breakage which generated the revert), the new
device id passed 0-day testing"
* tag 'tty-6.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
serial: exar: Add support for Sealevel 7xxxC serial cards
Revert "serial: stm32: Merge hard IRQ and threaded IRQ handling into single IRQ handler"
tty: serial: qcom_geni: avoid duplicate struct member init
serial: atmel: fix incorrect baudrate setup
tty: fix possible null-ptr-defer in spk_ttyio_release
serial: stm32: Merge hard IRQ and threaded IRQ handling into single IRQ handler
serial: amba-pl011: fix high priority character transmission in rs486 mode
serial: pch_uart: Pass correct sg to dma_unmap_sg()
tty: serial: qcom-geni-serial: fix slab-out-of-bounds on RX FIFO buffer
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Add support for Sealevel 7xxxC serial cards.
This patch:
* Adds IDs to recognize 7xxxC cards from Sealevel Systems.
* Updates exar_pci_probe() to set nr_ports to last two bytes of primary
dev ID for these cards.
Signed-off-by: Matthew Howell <matthew.howell@sealevel.com>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2301191440010.22558@tstest-VirtualBox
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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IRQ handler"
This reverts commit f24771b62a83239f0dce816bddf0f6807f436235 as it is
reported to break the build.
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/r/202301200130.ttBiTzfO-lkp@intel.com
Fixes: f24771b62a83 ("serial: stm32: Merge hard IRQ and threaded IRQ handling into single IRQ handler")
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Valentin Caron <valentin.caron@foss.st.com> # V3
Cc: Marek Vasut <marex@denx.de>
Cc: Johan Hovold <johan@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux
Pull printk fixes from Petr Mladek:
- Prevent a potential deadlock when configuring kgdb console
- Fix a kernel doc warning
* tag 'printk-for-6.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
kernel/printk/printk.c: Fix W=1 kernel-doc warning
tty: serial: kgdboc: fix mutex locking order for configure_kgdboc()
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When -Woverride-init is enabled in a build, gcc points out that
qcom_geni_serial_pm_ops contains conflicting initializers:
drivers/tty/serial/qcom_geni_serial.c:1586:20: error: initialized field overwritten [-Werror=override-init]
1586 | .restore = qcom_geni_serial_sys_hib_resume,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/tty/serial/qcom_geni_serial.c:1586:20: note: (near initialization for 'qcom_geni_serial_pm_ops.restore')
drivers/tty/serial/qcom_geni_serial.c:1587:17: error: initialized field overwritten [-Werror=override-init]
1587 | .thaw = qcom_geni_serial_sys_hib_resume,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Open-code the initializers with the version that was already used,
and use the pm_sleep_ptr() method to deal with unused ones,
in place of the __maybe_unused annotation.
Fixes: 35781d8356a2 ("tty: serial: qcom-geni-serial: Add support for Hibernation feature")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20221215165453.1864836-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Commit ba47f97a18f2 ("serial: core: remove baud_rates when serial console
setup") changed uart_set_options to select the correct baudrate
configuration based on the absolute error between requested baudrate and
available standard baudrate settings.
Prior to that commit the baudrate was selected based on which predefined
standard baudrate did not exceed the requested baudrate.
This change of selection logic was never reflected in the atmel serial
driver. Thus the comment left in the atmel serial driver is no longer
accurate.
Additionally the manual rounding up described in that comment and applied
via (quot - 1) requests an incorrect baudrate. Since uart_set_options uses
tty_termios_encode_baud_rate to determine the appropriate baudrate flags
this can cause baudrate selection to fail entirely because
tty_termios_encode_baud_rate will only select a baudrate if relative error
between requested and selected baudrate does not exceed +/-2%.
Fix that by requesting actual, exact baudrate used by the serial.
Fixes: ba47f97a18f2 ("serial: core: remove baud_rates when serial console setup")
Cc: stable <stable@kernel.org>
Signed-off-by: Tobias Schramm <t.schramm@manjaro.org>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Link: https://lore.kernel.org/r/20230109072940.202936-1-t.schramm@manjaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Requesting an interrupt with IRQF_ONESHOT will run the primary handler
in the hard-IRQ context even in the force-threaded mode. The
force-threaded mode is used by PREEMPT_RT in order to avoid acquiring
sleeping locks (spinlock_t) in hard-IRQ context. This combination
makes it impossible and leads to "sleeping while atomic" warnings.
Use one interrupt handler for both handlers (primary and secondary)
and drop the IRQF_ONESHOT flag which is not needed.
Fixes: e359b4411c283 ("serial: stm32: fix threaded interrupt handling")
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Valentin Caron <valentin.caron@foss.st.com> # V3
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230112180417.25595-1-marex@denx.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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In RS485 mode the transmission of a high priority character fails since it
is written to the data register before the transmitter is enabled. Fix this
in pl011_tx_chars() by enabling RS485 transmission before writing the
character.
Fixes: 8d479237727c ("serial: amba-pl011: add RS485 support")
Cc: stable@vger.kernel.org
Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com>
Link: https://lore.kernel.org/r/20230108181735.10937-1-LinoSanfilippo@gmx.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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A local variable sg is used to store scatterlist pointer in
pch_dma_tx_complete(). The for loop doing Tx byte accounting before
dma_unmap_sg() alters sg in its increment statement. Therefore, the
pointer passed into dma_unmap_sg() won't match to the one given to
dma_map_sg().
To fix the problem, use priv->sg_tx_p directly in dma_unmap_sg()
instead of the local variable.
Fixes: da3564ee027e ("pch_uart: add multi-scatter processing")
Cc: stable@vger.kernel.org
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230103093435.4396-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Driver's probe allocates memory for RX FIFO (port->rx_fifo) based on
default RX FIFO depth, e.g. 16. Later during serial startup the
qcom_geni_serial_port_setup() updates the RX FIFO depth
(port->rx_fifo_depth) to match real device capabilities, e.g. to 32.
The RX UART handle code will read "port->rx_fifo_depth" number of words
into "port->rx_fifo" buffer, thus exceeding the bounds. This can be
observed in certain configurations with Qualcomm Bluetooth HCI UART
device and KASAN:
Bluetooth: hci0: QCA Product ID :0x00000010
Bluetooth: hci0: QCA SOC Version :0x400a0200
Bluetooth: hci0: QCA ROM Version :0x00000200
Bluetooth: hci0: QCA Patch Version:0x00000d2b
Bluetooth: hci0: QCA controller version 0x02000200
Bluetooth: hci0: QCA Downloading qca/htbtfw20.tlv
bluetooth hci0: Direct firmware load for qca/htbtfw20.tlv failed with error -2
Bluetooth: hci0: QCA Failed to request file: qca/htbtfw20.tlv (-2)
Bluetooth: hci0: QCA Failed to download patch (-2)
==================================================================
BUG: KASAN: slab-out-of-bounds in handle_rx_uart+0xa8/0x18c
Write of size 4 at addr ffff279347d578c0 by task swapper/0/0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.1.0-rt5-00350-gb2450b7e00be-dirty #26
Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
Call trace:
dump_backtrace.part.0+0xe0/0xf0
show_stack+0x18/0x40
dump_stack_lvl+0x8c/0xb8
print_report+0x188/0x488
kasan_report+0xb4/0x100
__asan_store4+0x80/0xa4
handle_rx_uart+0xa8/0x18c
qcom_geni_serial_handle_rx+0x84/0x9c
qcom_geni_serial_isr+0x24c/0x760
__handle_irq_event_percpu+0x108/0x500
handle_irq_event+0x6c/0x110
handle_fasteoi_irq+0x138/0x2cc
generic_handle_domain_irq+0x48/0x64
If the RX FIFO depth changes after probe, be sure to resize the buffer.
Fixes: f9d690b6ece7 ("tty: serial: qcom_geni_serial: Allocate port->rx_fifo buffer in probe")
Cc: <stable@vger.kernel.org>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20221221164022.1087814-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Several mutexes are taken while setting up console serial ports. In
particular, the tty_port->mutex and @console_mutex are taken:
serial_pnp_probe
serial8250_register_8250_port
uart_add_one_port (locks tty_port->mutex)
uart_configure_port
register_console (locks @console_mutex)
In order to synchronize kgdb's tty_find_polling_driver() with
register_console(), commit 6193bc90849a ("tty: serial: kgdboc:
synchronize tty_find_polling_driver() and register_console()") takes
the @console_mutex. However, this leads to the following call chain
(with locking):
platform_probe
kgdboc_probe
configure_kgdboc (locks @console_mutex)
tty_find_polling_driver
uart_poll_init (locks tty_port->mutex)
uart_set_options
This is clearly deadlock potential due to the reverse lock ordering.
Since uart_set_options() requires holding @console_mutex in order to
serialize early initialization of the serial-console lock, take the
@console_mutex in uart_poll_init() instead of configure_kgdboc().
Since configure_kgdboc() was using @console_mutex for safe traversal
of the console list, change it to use the SRCU iterator instead.
Add comments to uart_set_options() kerneldoc mentioning that it
requires holding @console_mutex (aka the console_list_lock).
Fixes: 6193bc90849a ("tty: serial: kgdboc: synchronize tty_find_polling_driver() and register_console()")
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
[pmladek@suse.com: Export console_srcu_read_lock_is_held() to fix build kgdboc as a module.]
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20230112161213.1434854-1-john.ogness@linutronix.de
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial driver updates from Greg KH:
"Here is the "big" set of tty/serial driver changes for 6.2-rc1.
As in previous kernel releases, nothing big here at all, just some
small incremental serial/tty layer cleanups and some individual driver
additions and fixes. Highlights are:
- serial helper macros from Jiri Slaby to reduce the amount of
duplicated code in serial drivers
- api cleanups and consolidations from Ilpo Järvinen in lots of
serial drivers
- the usual set of n_gsm fixes from Daniel Starke as that code gets
exercised more
- TIOCSTI is finally able to be disabled if requested (security
hardening feature from Kees Cook)
- fsl_lpuart driver fixes and features added
- other small serial driver additions and fixes
All of these have been in linux-next for a while with no reported
problems"
* tag 'tty-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (97 commits)
serial: atmel: don't stop the transmitter when doing PIO
serial: atmel: cleanup atmel_start+stop_tx()
tty: serial: fsl_lpuart: switch to new dmaengine_terminate_* API
serial: sunsab: Fix error handling in sunsab_init()
serial: altera_uart: fix locking in polling mode
serial: pch: Fix PCI device refcount leak in pch_request_dma()
tty: serial: fsl_lpuart: Use pm_ptr() to avoid need to make pm __maybe_unused
tty: serial: fsl_lpuart: Add runtime pm support
tty: serial: fsl_lpuart: enable wakeup source for lpuart
serdev: Replace poll loop by readx_poll_timeout() macro
tty: synclink_gt: unwind actions in error path of net device open
serial: stm32: move dma_request_chan() before clk_prepare_enable()
dt-bindings: serial: xlnx,opb-uartlite: Drop 'contains' from 'xlnx,use-parity'
serial: pl011: Do not clear RX FIFO & RX interrupt in unthrottle.
serial: amba-pl011: avoid SBSA UART accessing DMACR register
tty: serial: altera_jtaguart: remove struct altera_jtaguart
tty: serial: altera_jtaguart: use uart_port::read_status_mask
tty: serial: altera_jtaguart: remove unused altera_jtaguart::sigs
tty: serial: altera_jtaguart: remove flag from altera_jtaguart_rx_chars()
n_tty: Rename tail to old_tail in n_tty_read()
...
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git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux
Pull printk updates from Petr Mladek:
- Add NMI-safe SRCU reader API. It uses atomic_inc() instead of
this_cpu_inc() on strong load-store architectures.
- Introduce new console_list_lock to synchronize a manipulation of the
list of registered consoles and their flags.
This is a first step in removing the big-kernel-lock-like behavior of
console_lock(). This semaphore still serializes console->write()
calbacks against:
- each other. It primary prevents potential races between early
and proper console drivers using the same device.
- suspend()/resume() callbacks and init() operations in some
drivers.
- various other operations in the tty/vt and framebufer
susbsystems. It is likely that console_lock() serializes even
operations that are not directly conflicting with the
console->write() callbacks here. This is the most complicated
big-kernel-lock aspect of the console_lock() that will be hard
to untangle.
- Introduce new console_srcu lock that is used to safely iterate and
access the registered console drivers under SRCU read lock.
This is a prerequisite for introducing atomic console drivers and
console kthreads. It will reduce the complexity of serialization
against normal consoles and console_lock(). Also it should remove the
risk of deadlock during critical situations, like Oops or panic, when
only atomic consoles are registered.
- Check whether the console is registered instead of enabled on many
locations. It was a historical leftover.
- Cleanly force a preferred console in xenfb code instead of a dirty
hack.
- A lot of code and comment clean ups and improvements.
* tag 'printk-for-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: (47 commits)
printk: htmldocs: add missing description
tty: serial: sh-sci: use setup() callback for early console
printk: relieve console_lock of list synchronization duties
tty: serial: kgdboc: use console_list_lock to trap exit
tty: serial: kgdboc: synchronize tty_find_polling_driver() and register_console()
tty: serial: kgdboc: use console_list_lock for list traversal
tty: serial: kgdboc: use srcu console list iterator
proc: consoles: use console_list_lock for list iteration
tty: tty_io: use console_list_lock for list synchronization
printk, xen: fbfront: create/use safe function for forcing preferred
netconsole: avoid CON_ENABLED misuse to track registration
usb: early: xhci-dbc: use console_is_registered()
tty: serial: xilinx_uartps: use console_is_registered()
tty: serial: samsung_tty: use console_is_registered()
tty: serial: pic32_uart: use console_is_registered()
tty: serial: earlycon: use console_is_registered()
tty: hvc: use console_is_registered()
efi: earlycon: use console_is_registered()
tty: nfcon: use console_is_registered()
serial_core: replace uart_console_enabled() with uart_console_registered()
...
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When setting up the early console, the setup() callback of the
regular console is used. It is called manually before registering
the early console instead of providing a setup() callback for the
early console. This is probably because the early setup needs a
different @options during the early stage.
The issue here is that the setup() callback is called without the
console_list_lock held and functions such as uart_set_options()
expect that.
Rather than manually calling the setup() function before registering,
provide an early console setup() callback that will use the different
early options. This ensures that the error checking, ordering, and
locking context when setting up the early console are correct.
Since this early console can only be registered via the earlyprintk=
parameter, the @options argument of the setup() callback will always
be NULL. Rather than simply ignoring the argument, add a WARN_ON()
to get our attention in case the setup() callback semantics should
change in the future.
Note that technically the current implementation works because it is
only used in early boot. And since the early console setup is
performed before registering, it cannot race with anything and thus
does not need any locking. However, longterm maintenance is easier
when drivers rely on the subsystem API rather than manually
implementing steps that could cause breakage in the future.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-41-john.ogness@linutronix.de
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kgdboc_earlycon_init() uses the console_lock to ensure that no consoles
are unregistered until the kgdboc_earlycon is setup. The console_list_lock
should be used instead because list synchronization responsibility will
be removed from the console_lock in a later change.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-39-john.ogness@linutronix.de
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register_console()
Calling tty_find_polling_driver() can lead to uart_set_options() being
called (via the poll_init() callback of tty_operations) to configure the
uart. But uart_set_options() can also be called by register_console()
(via the setup() callback of console).
Take the console_list_lock to synchronize against register_console() and
also use it for console list traversal. This also ensures the console list
cannot change until the polling console has been chosen.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-38-john.ogness@linutronix.de
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configure_kgdboc() uses the console_lock for console list iteration. Use
the console_list_lock instead because list synchronization responsibility
will be removed from the console_lock in a later change.
The SRCU iterator could have been used here, but a later change will
relocate the locking of the console_list_lock to also provide
synchronization against register_console().
Note, the console_lock is still needed to serialize the device()
callback with other console operations.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-37-john.ogness@linutronix.de
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Use srcu console list iteration for safe console list traversal.
Note that this is a preparatory change for when console_lock no
longer provides synchronization for the console list.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-36-john.ogness@linutronix.de
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It is not reliable to check for CON_ENABLED in order to identify if a
console is registered. Use console_is_registered() instead.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-30-john.ogness@linutronix.de
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It is not reliable to check for CON_ENABLED in order to identify if a
console is registered. Use console_is_registered() instead.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-29-john.ogness@linutronix.de
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It is not reliable to check for CON_ENABLED in order to identify if a
console is registered. Use console_is_registered() instead.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-28-john.ogness@linutronix.de
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It is not reliable to check for CON_ENABLED in order to identify if a
console is registered. Use console_is_registered() instead.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-27-john.ogness@linutronix.de
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All users of uart_console_enabled() really want to know if a console
is registered. It is not reliable to check for CON_ENABLED in order
to identify if a console is registered. Use console_is_registered()
instead.
A _locked() variant is provided because uart_set_options() is always
called with the console_list_lock held and must check if a console
is registered in order to synchronize with kgdboc.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-23-john.ogness@linutronix.de
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kgdboc_earlycon_init() uses the console_lock to ensure that no consoles
are unregistered until the kgdboc_earlycon is setup. This is necessary
because the trapping of the exit() callback assumes that the exit()
callback is not called before the trap is setup.
Explicitly document this non-typical console_lock usage.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-9-john.ogness@linutronix.de
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Unprotected list walks are not necessarily safe.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-2-john.ogness@linutronix.de
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Writing ATMEL_US_TXDIS to ATMEL_US_CR makes the transmitter NOT to send
the just queued character. This means when the character is last and
uart calls ops->stop_tx(), the character is not sent at all.
The usart datasheet is not much specific on this, it just says the
transmitter is stopped. But apparently, the character is dropped. So
we should stop the transmitter only for DMA and PDC transfers to not
send any more characters. For PIO, this is unexpected and deviates from
other drivers. In particular, the below referenced commit broke TX as it
added a call to ->stop_tx() after the very last character written to the
transmitter.
So fix this by limiting the write of ATMEL_US_TXDIS to DMA transfers
only.
Even there, I don't know if it is correctly implemented. Are all the
queued characters sent once ->start_tx() is called? Anyone tested flow
control -- be it hard (RTSCTS) or the soft (XOFF/XON) one?
Fixes: 2d141e683e9a ("tty: serial: use uart_port_tx() helper")
Cc: Richard Genoud <richard.genoud@gmail.com>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Claudiu Beznea <claudiu.beznea@microchip.com>
Cc: linux-arm-kernel@lists.infradead.org
Reported-by: Michael Walle <michael@walle.cc>
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20221123082736.24566-2-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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