linux/drivers/tty, branch v5.14

serial: 8250_pci: Avoid irq sharing for MSI(-X) interrupts.

2021-07-30T11:06:19Z

This attempts to fix a bug found with a serial port card which uses an MCS9922 chip, one of the 4 models for which MSI-X interrupts are currently supported. I don't possess such a card, and i'm not experienced with the serial subsystem, so this patch is based on what i think i found as a likely reason for failure, based on walking the user who actually owns the card through some diagnostic. The user who reported the problem finds the following in his dmesg output for the relevant ttyS4 and ttyS5: [ 0.580425] serial 0000:02:00.0: enabling device (0000 -> 0003) [ 0.601448] 0000:02:00.0: ttyS4 at I/O 0x3010 (irq = 125, base_baud = 115200) is a ST16650V2 [ 0.603089] serial 0000:02:00.1: enabling device (0000 -> 0003) [ 0.624119] 0000:02:00.1: ttyS5 at I/O 0x3000 (irq = 126, base_baud = 115200) is a ST16650V2 ... [ 6.323784] genirq: Flags mismatch irq 128. 00000080 (ttyS5) vs. 00000000 (xhci_hcd) [ 6.324128] genirq: Flags mismatch irq 128. 00000080 (ttyS5) vs. 00000000 (xhci_hcd) ... Output of setserial -a: /dev/ttyS4, Line 4, UART: 16650V2, Port: 0x3010, IRQ: 127 Baud_base: 115200, close_delay: 50, divisor: 0 closing_wait: 3000 Flags: spd_normal skip_test This suggests to me that the serial driver wants to register and share a MSI/MSI-X irq 128 with the xhci_hcd driver, whereas the xhci driver does not want to share the irq, as flags 0x00000080 (== IRQF_SHARED) from the serial port driver means to share the irq, and this mismatch ends in some failed irq init? With this setup, data reception works very unreliable, with dropped data, already at a transmission rate of only a 16 Bytes chunk every 1/120th of a second, ie. 1920 Bytes/sec, presumably due to rx fifo overflow due to mishandled or not used at all rx irq's? See full discussion thread with attempted diagnosis at: https://psychtoolbox.discourse.group/t/issues-with-iscan-serial-port-recording/3886 Disabling the use of MSI interrupts for the serial port pci card did fix the reliability problems. The user executed the following sequence of commands to achieve this: echo 0000:02:00.0 | sudo tee /sys/bus/pci/drivers/serial/unbind echo 0000:02:00.1 | sudo tee /sys/bus/pci/drivers/serial/unbind echo 0 | sudo tee /sys/bus/pci/devices/0000:02:00.0/msi_bus echo 0 | sudo tee /sys/bus/pci/devices/0000:02:00.1/msi_bus echo 0000:02:00.0 | sudo tee /sys/bus/pci/drivers/serial/bind echo 0000:02:00.1 | sudo tee /sys/bus/pci/drivers/serial/bind This resulted in the following log output: [ 82.179021] pci 0000:02:00.0: MSI/MSI-X disallowed for future drivers [ 87.003031] pci 0000:02:00.1: MSI/MSI-X disallowed for future drivers [ 98.537010] 0000:02:00.0: ttyS4 at I/O 0x3010 (irq = 17, base_baud = 115200) is a ST16650V2 [ 103.648124] 0000:02:00.1: ttyS5 at I/O 0x3000 (irq = 18, base_baud = 115200) is a ST16650V2 This patch attempts to fix the problem by disabling irq sharing when using MSI irq's. Note that all i know for sure is that disabling MSI irq's fixed the problem for the user, so this patch could be wrong and is untested. Please review with caution, keeping this in mind. Fixes: 8428413b1d14 ("serial: 8250_pci: Implement MSI(-X) support") Cc: Ralf Ramsauer Cc: stable Reviewed-by: Andy Shevchenko Signed-off-by: Mario Kleiner Link: https://lore.kernel.org/r/20210729043306.18528-1-mario.kleiner.de@gmail.com Signed-off-by: Greg Kroah-Hartman

serial: 8250_mtk: fix uart corruption issue when rx power off

2021-07-29T15:06:37Z

Fix uart corruption issue when rx power off. Add spin lock in mtk8250_dma_rx_complete function in APDMA mode. when uart is used as a communication port with external device(GPS). when external device(GPS) power off, the power of rx pin is also from 1.8v to 0v. Even if there is not any data in rx. But uart rx pin can capture the data "0". If uart don't receive any data in specified cycle, uart will generates BI(Break interrupt) interrupt. If external device(GPS) power off, we found that BI interrupt appeared continuously and very frequently. When uart interrupt type is BI, uart IRQ handler(8250 framwork API:serial8250_handle_irq) will push data to tty buffer. mtk8250_dma_rx_complete is a task of mtk_uart_apdma_rx_handler. mtk8250_dma_rx_complete priority is lower than uart irq handler(serial8250_handle_irq). if we are in process of mtk8250_dma_rx_complete, uart appear BI interrupt:1)serial8250_handle_irq will priority execution.2)it may cause write tty buffer conflict in mtk8250_dma_rx_complete. So the spin lock protect the rx receive data process is not break. Signed-off-by: Zhiyong Tao Cc: stable Link: https://lore.kernel.org/r/20210729084640.17613-2-zhiyong.tao@mediatek.com Signed-off-by: Greg Kroah-Hartman

tty: serial: fsl_lpuart: fix the wrong return value in lpuart32_get_mctrl

2021-07-29T15:05:59Z

Patch e60c2991f18b make the lpuart32_get_mctrl always return 0, actually this will break the functions of device which use flow control such as Bluetooth. For lpuart32 plaform, the hardware can handle the CTS automatically. So we should set TIOCM_CTS active. Also need to set CAR and DSR active. Patch has been tested on lpuart32 platforms such as imx8qm and imx8ulp. Fixes: e60c2991f18b ("serial: fsl_lpuart: remove RTSCTS handling from get_mctrl()") Cc: stable Signed-off-by: Sherry Sun Link: https://lore.kernel.org/r/20210729083109.31541-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman

serial: 8250_pci: Enumerate Elkhart Lake UARTs via dedicated driver

2021-07-21T10:54:11Z

Elkhart Lake UARTs are PCI enumerated Synopsys DesignWare v4.0+ UART integrated with Intel iDMA 32-bit DMA controller. There is a specific driver to handle them, i.e. 8250_lpss. Hence, disable 8250_pci enumeration for these UARTs. Fixes: 1b91d97c66ef ("serial: 8250_lpss: Add ->setup() for Elkhart Lake ports") Fixes: 4f912b898dc2 ("serial: 8250_lpss: Enable HS UART on Elkhart Lake") Cc: stable Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20210713101739.36962-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: 8250: fix handle_irq locking

2021-07-21T10:53:26Z

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. Add back an irqrestore-version of the sysrq port-unlock helper and use it in the 8250 callbacks that need it. Fixes: 75f4e830fa9c ("serial: do not restore interrupt state in sysrq helper") Cc: stable@vger.kernel.org # 5.13 Cc: Joel Stanley Cc: Andrew Jeffery Reported-by: kernel test robot Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20210714080427.28164-1-johan@kernel.org Signed-off-by: Greg Kroah-Hartman

serial: tegra: Only print FIFO error message when an error occurs

2021-07-21T10:53:00Z

The Tegra serial driver always prints an error message when enabling the FIFO for devices that have support for checking the FIFO enable status. Fix this by displaying the error message, only when an error occurs. Finally, update the error message to make it clear that enabling the FIFO failed and display the error code. Fixes: 222dcdff3405 ("serial: tegra: check for FIFO mode enabled status") Cc: Acked-by: Thierry Reding Signed-off-by: Jon Hunter Link: https://lore.kernel.org/r/20210630125643.264264-1-jonathanh@nvidia.com Signed-off-by: Greg Kroah-Hartman

serial: 8250: Mask out floating 16/32-bit bus bits

2021-07-21T10:52:14Z

Make sure only actual 8 bits of the IIR register are used in determining the port type in `autoconfig'. The `serial_in' port accessor returns the `unsigned int' type, meaning that with UPIO_AU, UPIO_MEM16, UPIO_MEM32, and UPIO_MEM32BE access types more than 8 bits of data are returned, of which the high order bits will often come from bus lines that are left floating in the data phase. For example with the MIPS Malta board's CBUS UART, where the registers are aligned on 8-byte boundaries and which uses 32-bit accesses, data as follows is returned: YAMON> dump -32 0xbf000900 0x40 BF000900: 1F000942 1F000942 1F000900 1F000900 ...B...B........ BF000910: 1F000901 1F000901 1F000900 1F000900 ................ BF000920: 1F000900 1F000900 1F000960 1F000960 ...........`...` BF000930: 1F000900 1F000900 1F0009FF 1F0009FF ................ YAMON> Evidently high-order 24 bits return values previously driven in the address phase (the 3 highest order address bits used with the command above are masked out in the simple virtual address mapping used here and come out at zeros on the external bus), a common scenario with bus lines left floating, due to bus capacitance. Consequently when the value of IIR, mapped at 0x1f000910, is retrieved in `autoconfig', it comes out at 0x1f0009c1 and when it is right-shifted by 6 and then assigned to 8-bit `scratch' variable, the value calculated is 0x27, not one of 0, 1, 2, 3 expected in port type determination. Fix the issue then, by assigning the value returned from `serial_in' to `scratch' first, which masks out 24 high-order bits retrieved, and only then right-shift the resulting 8-bit data quantity, producing the value of 3 in this case, as expected. Fix the same issue in `serial_dl_read'. The problem first appeared with Linux 2.6.9-rc3 which predates our repo history, but the origin could be identified with the old MIPS/Linux repo also at: as commit e0d2356c0777 ("Merge with Linux 2.6.9-rc3."), where code in `serial_in' was updated with this case: + case UPIO_MEM32: + return readl(up->port.membase + offset); + which made it produce results outside the unsigned 8-bit range for the first time, though obviously it is system dependent what actual values appear in the high order bits retrieved and it may well have been zeros in the relevant positions with the system the change originally was intended for. It is at that point that code in `autoconf' should have been updated accordingly, but clearly it was overlooked. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org # v2.6.12+ Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Maciej W. Rozycki Link: https://lore.kernel.org/r/alpine.DEB.2.21.2106260516220.37803@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman

serial: max310x: Unprepare and disable clock in error path

2021-07-21T10:51:54Z

In one error case the clock may be left prepared and enabled. Unprepare and disable clock in that case to balance state of the hardware. Fixes: d4d6f03c4fb3 ("serial: max310x: Try to get crystal clock rate from property") Reported-by: Dan Carpenter Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20210625153733.12911-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman

Merge tag 'for-linus-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml

2021-07-09T17:19:13Z

Pull UML updates from Richard Weinberger: - Support for optimized routines based on the host CPU - Support for PCI via virtio - Various fixes * tag 'for-linus-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: um: remove unneeded semicolon in um_arch.c um: Remove the repeated declaration um: fix error return code in winch_tramp() um: fix error return code in slip_open() um: Fix stack pointer alignment um: implement flush_cache_vmap/flush_cache_vunmap um: add a UML specific futex implementation um: enable the use of optimized xor routines in UML um: Add support for host CPU flags and alignment um: allow not setting extra rpaths in the linux binary um: virtio/pci: enable suspend/resume um: add PCI over virtio emulation driver um: irqs: allow invoking time-travel handler multiple times um: time-travel/signals: fix ndelay() in interrupt um: expose time-travel mode to userspace side um: export signals_enabled directly um: remove unused smp_sigio_handler() declaration lib: add iomem emulation (logic_iomem) um: allow disabling NO_IOMEM

Merge tag 'tty-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2021-07-05T21:08:24Z

Pull tty / serial updates from Greg KH: "Here is the big set of tty and serial driver patches for 5.14-rc1. A bit more than normal, but nothing major, lots of cleanups. Highlights are: - lots of tty api cleanups and mxser driver cleanups from Jiri - build warning fixes - various serial driver updates - coding style cleanups - various tty driver minor fixes and updates - removal of broken and disable r3964 line discipline (finally!) All of these have been in linux-next for a while with no reported issues" * tag 'tty-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (227 commits) serial: mvebu-uart: remove unused member nb from struct mvebu_uart arm64: dts: marvell: armada-37xx: Fix reg for standard variant of UART dt-bindings: mvebu-uart: fix documentation serial: mvebu-uart: correctly calculate minimal possible baudrate serial: mvebu-uart: do not allow changing baudrate when uartclk is not available serial: mvebu-uart: fix calculation of clock divisor tty: make linux/tty_flip.h self-contained serial: Prefer unsigned int to bare use of unsigned serial: 8250: 8250_omap: Fix possible interrupt storm on K3 SoCs serial: qcom_geni_serial: use DT aliases according to DT bindings Revert "tty: serial: Add UART driver for Cortina-Access platform" tty: serial: Add UART driver for Cortina-Access platform MAINTAINERS: add me back as mxser maintainer mxser: Documentation, fix typos mxser: Documentation, make the docs up-to-date mxser: Documentation, remove traces of callout device mxser: introduce mxser_16550A_or_MUST helper mxser: rename flags to old_speed in mxser_set_serial_info mxser: use port variable in mxser_set_serial_info mxser: access info->MCR under info->slock ...