linux/drivers/tty/serial, branch v6.2

serial: 8250_dma: Fix DMA Rx rearm race

2023-01-31T10:15:16Z

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 Tested-by: Gilles BULOZ Fixes: 9ee4b83e51f7 ("serial: 8250: Add support for dmaengine") Cc: stable@vger.kernel.org Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20230130114841.25749-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: 8250_dma: Fix DMA Rx completion race

2023-01-31T10:15:16Z

__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 Tested-by: Gilles BULOZ Fixes: 9ee4b83e51f7 ("serial: 8250: Add support for dmaengine") Cc: stable@vger.kernel.org Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20230130114841.25749-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: stm32: Merge hard IRQ and threaded IRQ handling into single IRQ handler

2023-01-31T10:15:01Z

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 Tested-by: Valentin Caron # V3 Signed-off-by: Marek Vasut Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230120160332.57930-1-marex@denx.de Signed-off-by: Greg Kroah-Hartman

Merge tag 'tty-6.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2023-01-21T19:12:42Z

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

serial: exar: Add support for Sealevel 7xxxC serial cards

2023-01-20T12:38:38Z

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 Cc: stable Link: https://lore.kernel.org/r/alpine.DEB.2.21.2301191440010.22558@tstest-VirtualBox Signed-off-by: Greg Kroah-Hartman

Revert "serial: stm32: Merge hard IRQ and threaded IRQ handling into single IRQ handler"

2023-01-20T10:18:36Z

This reverts commit f24771b62a83239f0dce816bddf0f6807f436235 as it is reported to break the build. Reported-by: kernel test robot 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 Cc: Valentin Caron # V3 Cc: Marek Vasut Cc: Johan Hovold Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

Merge tag 'printk-for-6.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

2023-01-19T20:32:07Z

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()

tty: serial: qcom_geni: avoid duplicate struct member init

2023-01-19T15:24:59Z

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 Reviewed-by: Douglas Anderson Link: https://lore.kernel.org/r/20221215165453.1864836-1-arnd@kernel.org Signed-off-by: Greg Kroah-Hartman

serial: atmel: fix incorrect baudrate setup

2023-01-19T15:24:39Z

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 Signed-off-by: Tobias Schramm Acked-by: Richard Genoud Link: https://lore.kernel.org/r/20230109072940.202936-1-t.schramm@manjaro.org Signed-off-by: Greg Kroah-Hartman

Merge branch 'rework/console-list-lock' into for-linus

2023-01-19T13:56:38Z