kernel/linux.git/drivers/tty/serial/8250, branch v6.3.2

serial: 8250: Add missing wakeup event reporting

2023-05-11T14:17:28+00:00

[ Upstream commit 0ba9e3a13c6adfa99e32b2576d20820ab10ad48a ] An 8250 UART configured as a wake-up source would not have reported itself through sysfs as being the source of wake-up, correct that. Fixes: b3b708fa2780 ("wake up from a serial port") Signed-off-by: Florian Fainelli Link: https://lore.kernel.org/r/20230414170241.2016255-1-f.fainelli@gmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: 8250_bcm7271: Fix arbitration handling

2023-05-11T14:17:24+00:00

[ Upstream commit 15ac1122fd6d4bf408a03e6f23c7ad4f60b22f9e ] The arbitration of the UART DMA is mishandled for a few exceptional cases when probing and releasing the driver. It is possible that the DMA register spaces are not defined in device tree for an instance of the driver, so attempts to access the registers in brcmuart_arbitration() would use NULL pointers. It is also possible for the probe function to return an error while still holding the UART DMA. This would prevent the UART DMA from being claimed by an instance that could use it. These errors are addressed by only releasing the UART DMA if it is held by this instance (i.e. priv->dma_enabled == 1) and directing early error paths in probe to this common release_dma handling. Fixes: 41a469482de2 ("serial: 8250: Add new 8250-core based Broadcom STB driver") Signed-off-by: Doug Berger Acked-by: Florian Fainelli Link: https://lore.kernel.org/r/20230309190224.687380-1-opendmb@gmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: 8250: Fix serial8250_tx_empty() race with DMA Tx

2023-05-11T14:16:49+00:00

commit 146a37e05d620cef4ad430e5d1c9c077fe6fa76f upstream. There's a potential race before THRE/TEMT deasserts when DMA Tx is starting up (or the next batch of continuous Tx is being submitted). This can lead to misdetecting Tx empty condition. It is entirely normal for THRE/TEMT to be set for some time after the DMA Tx had been setup in serial8250_tx_dma(). As Tx side is definitely not empty at that point, it seems incorrect for serial8250_tx_empty() claim Tx is empty. Fix the race by also checking in serial8250_tx_empty() whether there's DMA Tx active. Note: This fix only addresses in-kernel race mainly to make using TCSADRAIN/FLUSH robust. Userspace can still cause other races but they seem userspace concurrency control problems. Fixes: 9ee4b83e51f74 ("serial: 8250: Add support for dmaengine") Cc: stable@vger.kernel.org Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20230317113318.31327-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: 8250: Prevent starting up DMA Rx on THRI interrupt

2023-03-29T08:59:11+00:00

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 Tested-by: Hans de Goede Fixes: e8ffbb71f783 ("serial: 8250: use THRE & __stop_tx also with DMA") Cc: stable@vger.kernel.org Signed-off-by: Ilpo Järvinen Acked-by: Hans de Goede Link: https://lore.kernel.org/r/20230317103034.12881-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: 8250_pci1xxxx: Disable SERIAL_8250_PCI1XXXX config by default

2023-03-09T16:08:15+00:00

Commit 32bb477fa7bf ("serial: 8250_pci1xxxx: Add driver for quad-uart support") made the SERIAL_8250_PCI1XXXX driver enabled when SERIAL_8250 is enabled, disable it as this driver does not need to be enabled by default Fixes: 32bb477fa7bf ("serial: 8250_pci1xxxx: Add driver for quad-uart support") Reported-by: Linus Torvalds Link: https://lore.kernel.org/lkml/CAHk-=whhFCeeuo6vTEmNSx6S-KKkugxgzN_W5Z6v-9yH9gc3Zw@mail.gmail.com/ Signed-off-by: Kumaravel Thiagarajan Reviewed-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20230305145124.13444-1-kumaravel.thiagarajan@microchip.com Signed-off-by: Greg Kroah-Hartman

serial: 8250_fsl: fix handle_irq locking

2023-03-09T16:08:05+00:00

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 Link: https://lore.kernel.org/r/Y/xYzqp4ogmOF5t0@kili Signed-off-by: Johan Hovold Acked-by: Jiri Slaby Link: https://lore.kernel.org/r/20230227085046.24282-1-johan@kernel.org Signed-off-by: Greg Kroah-Hartman

serial: 8250_em: Fix UART port type

2023-03-09T16:07:05+00:00

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 Link: https://lore.kernel.org/r/20230227114152.22265-2-biju.das.jz@bp.renesas.com Signed-off-by: Greg Kroah-Hartman

serial: 8250: ASPEED_VUART: select REGMAP instead of depending on it

2023-03-09T16:06:49+00:00

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 Signed-off-by: Randy Dunlap Cc: Greg Kroah-Hartman Cc: Oskar Senft Cc: linux-serial@vger.kernel.org Link: https://lore.kernel.org/r/20230226053953.4681-9-rdunlap@infradead.org Signed-off-by: Greg Kroah-Hartman

serial: 8250_pci1xxxx: Add power management functions to quad-uart driver

2023-02-08T12:10:15+00:00

pci1xxxx's quad-uart function has the capability to wake up UART from suspend state. Enable wakeup before entering into suspend and disable wakeup on resume. Co-developed-by: Tharun Kumar P Signed-off-by: Tharun Kumar P Signed-off-by: Kumaravel Thiagarajan Link: https://lore.kernel.org/r/20230207164814.3104605-5-kumaravel.thiagarajan@microchip.com Signed-off-by: Greg Kroah-Hartman

serial: 8250_pci1xxxx: Add RS485 support to quad-uart driver

2023-02-08T12:10:15+00:00

pci1xxxx uart supports RS485 mode of operation in the hardware with auto-direction control with configurable delay for releasing RTS after the transmission. This patch adds support for the RS485 mode. Co-developed-by: Tharun Kumar P Signed-off-by: Tharun Kumar P Signed-off-by: Kumaravel Thiagarajan Reviewed-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20230207164814.3104605-4-kumaravel.thiagarajan@microchip.com Signed-off-by: Greg Kroah-Hartman