linux/drivers/tty/serial, branch v6.12

serial: qcom-geni: rename suspend functions

2024-10-11T06:39:24Z

Drop the unnecessary "_sys" infix from the suspend PM ops. Signed-off-by: Johan Hovold Reviewed-by: Douglas Anderson Link: https://lore.kernel.org/r/20241009145110.16847-10-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman

serial: qcom-geni: drop unused receive parameter

2024-10-11T06:39:23Z

Serial drivers should not be dropping characters themselves, but at least drop the unused 'drop' parameter from the receive handler for now. Reviewed-by: Douglas Anderson Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20241009145110.16847-9-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman

serial: qcom-geni: drop flip buffer WARN()

2024-10-11T06:39:23Z

Drop the unnecessary WARN() in case the TTY buffers are ever full in favour of a rate limited dev_err() which doesn't kill the machine when panic_on_warn is set. Reviewed-by: Douglas Anderson Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20241009145110.16847-8-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman

serial: qcom-geni: fix receiver enable

2024-10-11T06:39:23Z

The receiver is supposed to be enabled in the startup() callback and not in set_termios() which is called also during console setup. This specifically avoids accepting input before the port has been opened (and interrupts enabled), something which can also break the GENI firmware (cancel fails and after abort, the "stale" counter handling appears to be broken so that later input is not processed until twelve chars have been received). There also does not appear to be any need to keep the receiver disabled while updating the port settings. Since commit 6f3c3cafb115 ("serial: qcom-geni: disable interrupts during console writes") the calls to manipulate the secondary interrupts, which were done without holding the port lock, can also lead to the receiver being left disabled when set_termios() races with the console code (e.g. when init opens the tty during boot). This can manifest itself as a serial getty not accepting input. The calls to stop and start rx in set_termios() can similarly race with DMA completion and, for example, cause the DMA buffer to be unmapped twice or the mapping to be leaked. Fix this by only enabling the receiver during startup and while holding the port lock to avoid racing with the console code. Fixes: 6f3c3cafb115 ("serial: qcom-geni: disable interrupts during console writes") Fixes: 2aaa43c70778 ("tty: serial: qcom-geni-serial: add support for serial engine DMA") Fixes: c4f528795d1a ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP") Cc: stable@vger.kernel.org # 6.3 Cc: Bartosz Golaszewski Signed-off-by: Johan Hovold Reviewed-by: Douglas Anderson Link: https://lore.kernel.org/r/20241009145110.16847-6-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman

serial: qcom-geni: fix dma rx cancellation

2024-10-11T06:39:23Z

Make sure to wait for the DMA transfer to complete when cancelling the rx command on stop_rx(). This specifically prevents the DMA completion interrupt from firing after rx has been restarted, something which can lead to an IOMMU fault and hosed rx when the interrupt handler unmaps the DMA buffer for the new command: qcom_geni_serial 988000.serial: serial engine reports 0 RX bytes in! arm-smmu 15000000.iommu: FSR = 00000402 [Format=2 TF], SID=0x563 arm-smmu 15000000.iommu: FSYNR0 = 00210013 [S1CBNDX=33 WNR PLVL=3] Bluetooth: hci0: command 0xfc00 tx timeout Bluetooth: hci0: Reading QCA version information failed (-110) Also add the missing state machine reset which is needed in case cancellation fails. Fixes: 2aaa43c70778 ("tty: serial: qcom-geni-serial: add support for serial engine DMA") Cc: stable@vger.kernel.org # 6.3 Cc: Bartosz Golaszewski Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20241009145110.16847-5-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman

serial: qcom-geni: fix shutdown race

2024-10-11T06:39:23Z

A commit adding back the stopping of tx on port shutdown failed to add back the locking which had also been removed by commit e83766334f96 ("tty: serial: qcom_geni_serial: No need to stop tx/rx on UART shutdown"). Holding the port lock is needed to serialise against the console code, which may update the interrupt enable register and access the port state. Fixes: d8aca2f96813 ("tty: serial: qcom-geni-serial: stop operations in progress at shutdown") Fixes: 947cc4ecc06c ("serial: qcom-geni: fix soft lockup on sw flow control and suspend") Cc: stable@vger.kernel.org # 6.3 Reviewed-by: Bartosz Golaszewski Signed-off-by: Johan Hovold Reviewed-by: Douglas Anderson Link: https://lore.kernel.org/r/20241009145110.16847-4-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman

serial: qcom-geni: revert broken hibernation support

2024-10-11T06:39:23Z

This reverts commit 35781d8356a2eecaa6074ceeb80ee22e252fcdae. Hibernation is not supported on Qualcomm platforms with mainline kernels yet a broken vendor implementation for the GENI serial driver made it upstream. This is effectively dead code that cannot be tested and should just be removed, but if these paths were ever hit for an open non-console port they would crash the machine as the driver would fail to enable clocks during restore() (i.e. all ports would have to be closed by drivers and user space before hibernating the system to avoid this as a comment in the code hinted at). The broken implementation also added a random call to enable the receiver in the port setup code where it does not belong and which enables the receiver prematurely for console ports. Fixes: 35781d8356a2 ("tty: serial: qcom-geni-serial: Add support for Hibernation feature") Cc: stable@vger.kernel.org # 6.2 Cc: Aniket Randive Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20241009145110.16847-3-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman

serial: qcom-geni: fix polled console initialisation

2024-10-11T06:39:23Z

The polled console (KGDB/KDB) implementation must not call port setup unconditionally as the port may already be in use by the console or a getty. Only make sure that the receiver is enabled, but do not enable any device interrupts. Fixes: d8851a96ba25 ("tty: serial: qcom-geni-serial: Add a poll_init() function") Cc: stable@vger.kernel.org # 6.4 Cc: Douglas Anderson Signed-off-by: Johan Hovold Reviewed-by: Douglas Anderson Link: https://lore.kernel.org/r/20241009145110.16847-2-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman

serial: imx: Update mctrl old_status on RTSD interrupt

2024-10-11T06:28:45Z

When sending data using DMA at high baudrate (4 Mbdps in local test case) to a device with small RX buffer which keeps asserting RTS after every received byte, it is possible that the iMX UART driver would not recognize the falling edge of RTS input signal and get stuck, unable to transmit any more data. This condition happens when the following sequence of events occur: - imx_uart_mctrl_check() is called at some point and takes a snapshot of UART control signal status into sport->old_status using imx_uart_get_hwmctrl(). The RTSS/TIOCM_CTS bit is of interest here (*). - DMA transfer occurs, the remote device asserts RTS signal after each byte. The i.MX UART driver recognizes each such RTS signal change, raises an interrupt with USR1 register RTSD bit set, which leads to invocation of __imx_uart_rtsint(), which calls uart_handle_cts_change(). - If the RTS signal is deasserted, uart_handle_cts_change() clears port->hw_stopped and unblocks the port for further data transfers. - If the RTS is asserted, uart_handle_cts_change() sets port->hw_stopped and blocks the port for further data transfers. This may occur as the last interrupt of a transfer, which means port->hw_stopped remains set and the port remains blocked (**). - Any further data transfer attempts will trigger imx_uart_mctrl_check(), which will read current status of UART control signals by calling imx_uart_get_hwmctrl() (***) and compare it with sport->old_status . - If current status differs from sport->old_status for RTS signal, uart_handle_cts_change() is called and possibly unblocks the port by clearing port->hw_stopped . - If current status does not differ from sport->old_status for RTS signal, no action occurs. This may occur in case prior snapshot (*) was taken before any transfer so the RTS is deasserted, current snapshot (***) was taken after a transfer and therefore RTS is deasserted again, which means current status and sport->old_status are identical. In case (**) triggered when RTS got asserted, and made port->hw_stopped set, the port->hw_stopped will remain set because no change on RTS line is recognized by this driver and uart_handle_cts_change() is not called from here to unblock the port->hw_stopped. Update sport->old_status in __imx_uart_rtsint() accordingly to make imx_uart_mctrl_check() detect such RTS change. Note that TIOCM_CAR and TIOCM_RI bits in sport->old_status do not suffer from this problem. Fixes: ceca629e0b48 ("[ARM] 2971/1: i.MX uart handle rts irq") Cc: stable Reviewed-by: Esben Haabendal Signed-off-by: Marek Vasut Link: https://lore.kernel.org/r/20241002184133.19427-1-marex@denx.de Signed-off-by: Greg Kroah-Hartman

move asm/unaligned.h to linux/unaligned.h

2024-10-02T21:23:23Z

asm/unaligned.h is always an include of asm-generic/unaligned.h; might as well move that thing to linux/unaligned.h and include that - there's nothing arch-specific in that header. auto-generated by the following: for i in `git grep -l -w asm/unaligned.h`; do sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i done for i in `git grep -l -w asm-generic/unaligned.h`; do sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i done git mv include/asm-generic/unaligned.h include/linux/unaligned.h git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h