linux/drivers/tty/serial, branch v6.4

tty: serial: fsl_lpuart: reduce RX watermark to 0 on LS1028A

2023-06-13T10:31:45Z

LS1028A is using DMA with LPUART. Having RX watermark set to 1, means DMA transactions are started only after receiving the second character. On other platforms with newer LPUART IP, Receiver Idle Empty function initiates the DMA request after the receiver is idling for 4 characters. But this feature is missing on LS1028A, which is causing a 1-character delay in the RX direction on this platform. Set RX watermark to 0 to initiate RX DMA after each character. Link: https://lore.kernel.org/linux-serial/20230607103459.1222426-1-robert.hodaszi@digi.com/ Fixes: 9ad9df844754 ("tty: serial: fsl_lpuart: Fix the wrong RXWATER setting for rx dma case") Cc: stable Signed-off-by: Robert Hodaszi Message-ID: <20230609121334.1878626-1-robert.hodaszi@digi.com> Signed-off-by: Greg Kroah-Hartman

serial: lantiq: add missing interrupt ack

2023-06-06T12:45:34Z

Currently, the error interrupt is never acknowledged, so once active it will stay active indefinitely, causing the handler to be called in an infinite loop. Fixes: 2f0fc4159a6a ("SERIAL: Lantiq: Add driver for MIPS Lantiq SOCs.") Cc: Signed-off-by: Bernhard Seibold Reviewed-by: Ilpo Järvinen Message-ID: <20230602133029.546-1-mail@bernhard-seibold.de> Signed-off-by: Greg Kroah-Hartman

serial: cpm_uart: Fix a COMPILE_TEST dependency

2023-05-30T11:25:47Z

In a COMPILE_TEST configuration, the cpm_uart driver uses symbols from the cpm_uart_cpm2.c file. This file is compiled only when CONFIG_CPM2 is set. Without this dependency, the linker fails with some missing symbols for COMPILE_TEST configuration that needs SERIAL_CPM without enabling CPM2. This lead to: depends on CPM2 || CPM1 || (PPC32 && CPM2 && COMPILE_TEST) This dependency does not make sense anymore and can be simplified removing all the COMPILE_TEST part. Signed-off-by: Herve Codina Reported-by: kernel test robot Link: https://lore.kernel.org/oe-kbuild-all/202305160221.9XgweObz-lkp@intel.com/ Fixes: e3e7b13bffae ("serial: allow COMPILE_TEST for some drivers") Cc: stable Link: https://lore.kernel.org/r/20230523085902.75837-3-herve.codina@bootlin.com Signed-off-by: Greg Kroah-Hartman

tty: serial: fsl_lpuart: use UARTCTRL_TXINV to send break instead of UARTCTRL_SBK

2023-05-30T11:24:27Z

LPUART IP now has two known bugs, one is that CTS has higher priority than the break signal, which causes the break signal sending through UARTCTRL_SBK may impacted by the CTS input if the HW flow control is enabled. It exists on all platforms we support in this driver. So we add a workaround patch for this issue: commit c4c81db5cf8b ("tty: serial: fsl_lpuart: disable the CTS when send break signal"). Another IP bug is i.MX8QM LPUART may have an additional break character being sent after SBK was cleared. It may need to add some delay between clearing SBK and re-enabling CTS to ensure that the SBK latch are completely cleared. But we found that during the delay period before CTS is enabled, there is still a risk that Bluetooth data in TX FIFO may be sent out during this period because of break off and CTS disabled(even if BT sets CTS line deasserted, data is still sent to BT). Due to this risk, we have to drop the CTS-disabling workaround for SBK bugs, use TXINV seems to be a better way to replace SBK feature and avoid above risk. Also need to disable the transmitter to prevent any data from being sent out during break, then invert the TX line to send break. Then disable the TXINV when turn off break and re-enable transmitter. Fixes: c4c81db5cf8b ("tty: serial: fsl_lpuart: disable the CTS when send break signal") Cc: stable Signed-off-by: Sherry Sun Link: https://lore.kernel.org/r/20230519094751.28948-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman

serial: 8250_tegra: Fix an error handling path in tegra_uart_probe()

2023-05-30T11:24:07Z

If an error occurs after reset_control_deassert(), it must be re-asserted, as already done in the .remove() function. Fixes: c6825c6395b7 ("serial: 8250_tegra: Create Tegra specific 8250 driver") Cc: stable Signed-off-by: Christophe JAILLET Link: https://lore.kernel.org/r/f8130f35339cc80edc6b9aac4bb2a60b60a226bf.1684063511.git.christophe.jaillet@wanadoo.fr Signed-off-by: Greg Kroah-Hartman

serial: qcom-geni: fix enabling deactivated interrupt

2023-05-13T11:00:54Z

The driver have a race, experienced only with PREEMPT_RT patchset: CPU0 | CPU1 ================================================================== qcom_geni_serial_probe | uart_add_one_port | | serdev_drv_probe | qca_serdev_probe | serdev_device_open | uart_open | uart_startup | qcom_geni_serial_startup | enable_irq | __irq_startup | WARN_ON() | IRQ not activated request_threaded_irq | irq_domain_activate_irq | The warning: 894000.serial: ttyHS1 at MMIO 0x894000 (irq = 144, base_baud = 0) is a MSM serial serial0: tty port ttyHS1 registered WARNING: CPU: 7 PID: 107 at kernel/irq/chip.c:241 __irq_startup+0x78/0xd8 ... qcom_geni_serial 894000.serial: serial engine reports 0 RX bytes in! Adding UART port triggers probe of child serial devices - serdev and eventually Qualcomm Bluetooth hci_qca driver. This opens UART port which enables the interrupt before it got activated in request_threaded_irq(). The issue originates in commit f3974413cf02 ("tty: serial: qcom_geni_serial: Wakeup IRQ cleanup") and discussion on mailing list [1]. However the above commit does not explain why the uart_add_one_port() is moved above requesting interrupt. [1] https://lore.kernel.org/all/5d9f3dfa.1c69fb81.84c4b.30bf@mx.google.com/ Fixes: f3974413cf02 ("tty: serial: qcom_geni_serial: Wakeup IRQ cleanup") Cc: Cc: Stephen Boyd Signed-off-by: Krzysztof Kozlowski Reviewed-by: Stephen Boyd Link: https://lore.kernel.org/r/20230505152301.2181270-1-krzysztof.kozlowski@linaro.org Signed-off-by: Greg Kroah-Hartman

serial: 8250_bcm7271: fix leak in `brcmuart_probe`

2023-05-13T10:56:01Z

Smatch reports: drivers/tty/serial/8250/8250_bcm7271.c:1120 brcmuart_probe() warn: 'baud_mux_clk' from clk_prepare_enable() not released on lines: 1032. The issue is fixed by using a managed clock. Fixes: 41a469482de2 ("serial: 8250: Add new 8250-core based Broadcom STB driver") Reported-by: XuDong Liu Link: https://lore.kernel.org/lkml/20230424125100.4783-1-m202071377@hust.edu.cn/ Signed-off-by: Doug Berger Acked-by: Florian Fainelli Link: https://lore.kernel.org/r/20230427181916.2983697-3-opendmb@gmail.com Signed-off-by: Greg Kroah-Hartman

serial: 8250_bcm7271: balance clk_enable calls

2023-05-13T10:56:01Z

The sw_baud clock must be disabled when the device driver is not connected to the device. This now occurs when probe fails and upon remove. Fixes: 41a469482de2 ("serial: 8250: Add new 8250-core based Broadcom STB driver") Reported-by: XuDong Liu Link: https://lore.kernel.org/lkml/20230424125100.4783-1-m202071377@hust.edu.cn/ Signed-off-by: Doug Berger Acked-by: Florian Fainelli Link: https://lore.kernel.org/r/20230427181916.2983697-2-opendmb@gmail.com Signed-off-by: Greg Kroah-Hartman

serial: arc_uart: fix of_iomap leak in `arc_serial_probe`

2023-05-13T10:55:46Z

Smatch reports: drivers/tty/serial/arc_uart.c:631 arc_serial_probe() warn: 'port->membase' from of_iomap() not released on lines: 631. In arc_serial_probe(), if uart_add_one_port() fails, port->membase is not released, which would cause a resource leak. To fix this, I replace of_iomap with devm_platform_ioremap_resource. Fixes: 8dbe1d5e09a7 ("serial/arc: inline the probe helper") Signed-off-by: Ke Zhang Reviewed-by: Dongliang Mu Link: https://lore.kernel.org/r/20230428031636.44642-1-m202171830@hust.edu.cn Signed-off-by: Greg Kroah-Hartman

serial: 8250: Document termios parameter of serial8250_em485_config()

2023-05-13T10:55:23Z

With W=1: drivers/tty/serial/8250/8250_port.c:679: warning: Function parameter or member 'termios' not described in 'serial8250_em485_config' Fix this by documenting the parameter. Fixes: ae50bb2752836277 ("serial: take termios_rwsem for ->rs485_config() & pass termios as param") Signed-off-by: Geert Uytterhoeven Reviewed-by: Jiri Slaby Link: https://lore.kernel.org/r/2bd1e62be1d5d33333002910372feecc6d52e78f.1682071013.git.geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman