kernel/linux.git/drivers/tty/serial/8250, branch v5.4.50

serial: 8250: Fix max baud limit in generic 8250 port

2020-06-24T15:50:13+00:00

[ Upstream commit 7b668c064ec33f3d687c3a413d05e355172e6c92 ] Standard 8250 UART ports are designed in a way so they can communicate with baud rates up to 1/16 of a reference frequency. It's expected from most of the currently supported UART controllers. That's why the former version of serial8250_get_baud_rate() method called uart_get_baud_rate() with min and max baud rates passed as (port->uartclk / 16 / UART_DIV_MAX) and ((port->uartclk + tolerance) / 16) respectively. Doing otherwise, like it was suggested in commit ("serial: 8250_mtk: support big baud rate."), caused acceptance of bauds, which was higher than the normal UART controllers actually supported. As a result if some user-space program requested to set a baud greater than (uartclk / 16) it would have been permitted without truncation, but then serial8250_get_divisor(baud) (which calls uart_get_divisor() to get the reference clock divisor) would have returned a zero divisor. Setting zero divisor will cause an unpredictable effect varying from chip to chip. In case of DW APB UART the communications just stop. Lets fix this problem by getting back the limitation of (uartclk + tolerance) / 16 maximum baud supported by the generic 8250 port. Mediatek 8250 UART ports driver developer shouldn't have touched it in the first place notably seeing he already provided a custom version of set_termios() callback in that glue-driver which took into account the extended baud rate values and accordingly updated the standard and vendor-specific divisor latch registers anyway. Fixes: 81bb549fdf14 ("serial: 8250_mtk: support big baud rate.") Signed-off-by: Serge Semin Cc: Alexey Malahov Cc: Thomas Bogendoerfer Cc: Paul Burton Cc: Ralf Baechle Cc: Arnd Bergmann Cc: Long Cheng Cc: Andy Shevchenko Cc: Maxime Ripard Cc: Catalin Marinas Cc: Will Deacon Cc: Russell King Cc: linux-mips@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mediatek@lists.infradead.org Link: https://lore.kernel.org/r/20200506233136.11842-2-Sergey.Semin@baikalelectronics.ru Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: 8250: Avoid error message on reprobe

2020-06-22T07:31:18+00:00

commit e0a851fe6b9b619527bd928aa93caaddd003f70c upstream. If the call to uart_add_one_port() in serial8250_register_8250_port() fails, a half-initialized entry in the serial_8250ports[] array is left behind. A subsequent reprobe of the same serial port causes that entry to be reused. Because uart->port.dev is set, uart_remove_one_port() is called for the half-initialized entry and bails out with an error message: bcm2835-aux-uart 3f215040.serial: Removing wrong port: (null) != (ptrval) The same happens on failure of mctrl_gpio_init() since commit 4a96895f74c9 ("tty/serial/8250: use mctrl_gpio helpers"). Fix by zeroing the uart->port.dev pointer in the probe error path. The bug was introduced in v2.6.10 by historical commit befff6f5bf5f ("[SERIAL] Add new port registration/unregistration functions."): https://git.kernel.org/tglx/history/c/befff6f5bf5f The commit added an unconditional call to uart_remove_one_port() in serial8250_register_port(). In v3.7, commit 835d844d1a28 ("8250_pnp: do pnp probe before legacy probe") made that call conditional on uart->port.dev which allows me to fix the issue by zeroing that pointer in the error path. Thus, the present commit will fix the problem as far back as v3.7 whereas still older versions need to also cherry-pick 835d844d1a28. Fixes: 835d844d1a28 ("8250_pnp: do pnp probe before legacy probe") Signed-off-by: Lukas Wunner Cc: stable@vger.kernel.org # v2.6.10 Cc: stable@vger.kernel.org # v2.6.10: 835d844d1a28: 8250_pnp: do pnp probe before legacy Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/b4a072013ee1a1d13ee06b4325afb19bda57ca1b.1589285873.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman

serial: 8250_pci: Move Pericom IDs to pci_ids.h

2020-06-22T07:31:17+00:00

[ Upstream commit 62a7f3009a460001eb46984395280dd900bc4ef4 ] Move the IDs to pci_ids.h so it can be used by next patch. Link: https://lore.kernel.org/r/20200508065343.32751-1-kai.heng.feng@canonical.com Signed-off-by: Kai-Heng Feng Signed-off-by: Bjorn Helgaas Acked-by: Greg Kroah-Hartman Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin

serial: 8250_exar: add support for ACCES cards

2020-03-12T12:00:20+00:00

commit 10c5ccc3c6d32f3d7d6c07de1d3f0f4b52f3e3ab upstream. Add ACCES VIDs and PIDs that use the Exar chips Signed-off-by: Jay Dolan Cc: stable Link: https://lore.kernel.org/r/20200305140504.22237-1-jay.dolan@accesio.com Signed-off-by: Greg Kroah-Hartman

serial: 8250: Check UPF_IRQ_SHARED in advance

2020-02-28T16:22:19+00:00

commit 7febbcbc48fc92e3f33863b32ed715ba4aff18c4 upstream. The commit 54e53b2e8081 ("tty: serial: 8250: pass IRQ shared flag to UART ports") nicely explained the problem: ---8<---8<--- On some systems IRQ lines between multiple UARTs might be shared. If so, the irqflags have to be configured accordingly. The reason is: The 8250 port startup code performs IRQ tests *before* the IRQ handler for that particular port is registered. This is performed in serial8250_do_startup(). This function checks whether IRQF_SHARED is configured and only then disables the IRQ line while testing. This test is performed upon each open() of the UART device. Imagine two UARTs share the same IRQ line: On is already opened and the IRQ is active. When the second UART is opened, the IRQ line has to be disabled while performing IRQ tests. Otherwise an IRQ might handler might be invoked, but the IRQ itself cannot be handled, because the corresponding handler isn't registered, yet. That's because the 8250 code uses a chain-handler and invokes the corresponding port's IRQ handling routines himself. Unfortunately this IRQF_SHARED flag isn't configured for UARTs probed via device tree even if the IRQs are shared. This way, the actual and shared IRQ line isn't disabled while performing tests and the kernel correctly detects a spurious IRQ. So, adding this flag to the DT probe solves the issue. Note: The UPF_SHARE_IRQ flag is configured unconditionally. Therefore, the IRQF_SHARED flag can be set unconditionally as well. Example stack trace by performing `echo 1 > /dev/ttyS2` on a non-patched system: |irq 85: nobody cared (try booting with the "irqpoll" option) | [...] |handlers: |[] irq_default_primary_handler threaded [] serial8250_interrupt |Disabling IRQ #85 ---8<---8<--- But unfortunately didn't fix the root cause. Let's try again here by moving IRQ flag assignment from serial_link_irq_chain() to serial8250_do_startup(). This should fix the similar issue reported for 8250_pnp case. Since this change we don't need to have custom solutions in 8250_aspeed_vuart and 8250_of drivers, thus, drop them. Fixes: 1c2f04937b3e ("serial: 8250: add IRQ trigger support") Reported-by: Li RongQing Cc: Kurt Kanzenbach Cc: Vikram Pandita Signed-off-by: Andy Shevchenko Cc: stable Acked-by: Kurt Kanzenbach Link: https://lore.kernel.org/r/20200211135559.85960-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: 8250_bcm2835aux: Fix line mismatch on driver unbind

2020-02-01T09:34:34+00:00

commit dc76697d7e933d5e299116f219c890568785ea15 upstream. Unbinding the bcm2835aux UART driver raises the following error if the maximum number of 8250 UARTs is set to 1 (via the 8250.nr_uarts module parameter or CONFIG_SERIAL_8250_RUNTIME_UARTS): (NULL device *): Removing wrong port: a6f80333 != fa20408b That's because bcm2835aux_serial_probe() retrieves UART line number 1 from the devicetree and stores it in data->uart.port.line, while serial8250_register_8250_port() instead uses UART line number 0, which is stored in data->line. On driver unbind, bcm2835aux_serial_remove() uses data->uart.port.line, which contains the wrong number. Fix it. The issue does not occur if the maximum number of 8250 UARTs is >= 2. Fixes: bdc5f3009580 ("serial: bcm2835: add driver for bcm2835-aux-uart") Signed-off-by: Lukas Wunner Cc: stable@vger.kernel.org # v4.6+ Cc: Martin Sperl Reviewed-by: Nicolas Saenz Julienne Tested-by: Nicolas Saenz Julienne Link: https://lore.kernel.org/r/912ccf553c5258135c6d7e8f404a101ef320f0f4.1579175223.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman

Revert "serial/8250: Add support for NI-Serial PXI/PXIe+485 devices"

2019-12-13T07:43:22+00:00

commit 27ed14d0ecb38516b6f3c6fdcd62c25c9454f979 upstream. This reverts commit fdc2de87124f5183a98ea7eced1f76dbdba22951 ("serial/8250: Add support for NI-Serial PXI/PXIe+485 devices"). The commit fdc2de87124f ("serial/8250: Add support for NI-Serial PXI/PXIe+485 devices") introduced a breakage on NI-Serial PXI(e)-RS485 devices, RS-232 variants have no issue. The Linux system can enumerate the NI-Serial PXI(e)-RS485 devices, but it broke the R/W operation on the ports. However, the implementation is working on the NI internal Linux RT kernel but it does not work in the Linux main tree kernel. This is only affecting NI products, specifically the RS-485 variants. Reverting the upstream until a proper implementation that can apply to both NI internal Linux kernel and Linux mainline kernel is figured out. Signed-off-by: Je Yen Tam Fixes: fdc2de87124f ("serial/8250: Add support for NI-Serial PXI/PXIe+485 devices") Cc: stable Link: https://lore.kernel.org/r/20191127075301.9866-1-je.yen.tam@ni.com Signed-off-by: Greg Kroah-Hartman

serial: 8250_dw: Avoid double error messaging when IRQ absent

2019-12-13T07:42:25+00:00

commit 05faa64e73924556ba281911db24643e438fe7ba upstream. Since the commit 7723f4c5ecdb ("driver core: platform: Add an error message to platform_get_irq*()") platform_get_irq() started issuing an error message. Thus, there is no need to have the same in the driver Fixes: 7723f4c5ecdb ("driver core: platform: Add an error message to platform_get_irq*()") Signed-off-by: Andy Shevchenko Cc: stable Link: https://lore.kernel.org/r/20191023103558.51862-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: 8250-mtk: Use platform_get_irq_optional() for optional irq

2019-12-13T07:42:21+00:00

commit eb9c1a41ea1234907615fe47d6e47db8352d744b upstream. As platform_get_irq() now prints an error when the interrupt does not exist, this warnings are printed on bananapi-r2: [ 4.935780] mt6577-uart 11004000.serial: IRQ index 1 not found [ 4.962589] 11002000.serial: ttyS1 at MMIO 0x11002000 (irq = 202, base_baud = 1625000) is a ST16650V2 [ 4.972127] mt6577-uart 11002000.serial: IRQ index 1 not found [ 4.998927] 11003000.serial: ttyS2 at MMIO 0x11003000 (irq = 203, base_baud = 1625000) is a ST16650V2 [ 5.008474] mt6577-uart 11003000.serial: IRQ index 1 not found Fix this by calling platform_get_irq_optional() instead. now it looks like this: [ 4.872751] Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled Fixes: 7723f4c5ecdb8d83 ("driver core: platform: Add an error message to platform_get_irq*()") Signed-off-by: Frank Wunderlich Cc: stable Link: https://lore.kernel.org/r/20191027062117.20389-1-frank-w@public-files.de Signed-off-by: Greg Kroah-Hartman

8250-men-mcb: fix error checking when get_num_ports returns -ENODEV

2019-10-15T19:38:41+00:00

The current checking for failure on the number of ports fails when -ENODEV is returned from the call to get_num_ports. Fix this by making num_ports and loop counter i signed rather than unsigned ints. Also add check for num_ports being less than zero to check for -ve error returns. Addresses-Coverity: ("Unsigned compared against 0") Fixes: e2fea54e4592 ("8250-men-mcb: add support for 16z025 and 16z057") Signed-off-by: Colin Ian King Reviewed-by: Michael Moese Link: https://lore.kernel.org/r/20191013220016.9369-1-colin.king@canonical.com Signed-off-by: Greg Kroah-Hartman