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2024-10-22serial: qcom-geni: fix receiver enableJohan Hovold1-4/+6
commit fa103d2599e11e802c818684cff821baefe7f206 upstream. 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 <bartosz.golaszewski@linaro.org> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20241009145110.16847-6-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-22serial: qcom-geni: fix dma rx cancellationJohan Hovold1-4/+14
commit 23ee4a25661c33e6381d41e848a9060ed6d72845 upstream. 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 <bartosz.golaszewski@linaro.org> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Link: https://lore.kernel.org/r/20241009145110.16847-5-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-22serial: qcom-geni: fix shutdown raceJohan Hovold1-0/+2
commit 23f5f5debcaac1399cfeacec215278bf6dbc1d11 upstream. 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 <bartosz.golaszewski@linaro.org> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20241009145110.16847-4-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-22serial: qcom-geni: revert broken hibernation supportJohan Hovold1-39/+2
commit 19df76662a33d2f2fc41a66607cb8285fc02d6ec upstream. 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 <quic_arandive@quicinc.com> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Link: https://lore.kernel.org/r/20241009145110.16847-3-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-22serial: qcom-geni: fix polled console initialisationJohan Hovold1-1/+19
commit 4bef7c6f299910f19876ad8e7f5897514855f1d2 upstream. 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 <dianders@chromium.org> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20241009145110.16847-2-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-22tty: n_gsm: Fix use-after-free in gsm_cleanup_muxLonglong Xia1-0/+2
commit 9462f4ca56e7d2430fdb6dcc8498244acbfc4489 upstream. BUG: KASAN: slab-use-after-free in gsm_cleanup_mux+0x77b/0x7b0 drivers/tty/n_gsm.c:3160 [n_gsm] Read of size 8 at addr ffff88815fe99c00 by task poc/3379 CPU: 0 UID: 0 PID: 3379 Comm: poc Not tainted 6.11.0+ #56 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 Call Trace: <TASK> gsm_cleanup_mux+0x77b/0x7b0 drivers/tty/n_gsm.c:3160 [n_gsm] __pfx_gsm_cleanup_mux+0x10/0x10 drivers/tty/n_gsm.c:3124 [n_gsm] __pfx_sched_clock_cpu+0x10/0x10 kernel/sched/clock.c:389 update_load_avg+0x1c1/0x27b0 kernel/sched/fair.c:4500 __pfx_min_vruntime_cb_rotate+0x10/0x10 kernel/sched/fair.c:846 __rb_insert_augmented+0x492/0xbf0 lib/rbtree.c:161 gsmld_ioctl+0x395/0x1450 drivers/tty/n_gsm.c:3408 [n_gsm] _raw_spin_lock_irqsave+0x92/0xf0 arch/x86/include/asm/atomic.h:107 __pfx_gsmld_ioctl+0x10/0x10 drivers/tty/n_gsm.c:3822 [n_gsm] ktime_get+0x5e/0x140 kernel/time/timekeeping.c:195 ldsem_down_read+0x94/0x4e0 arch/x86/include/asm/atomic64_64.h:79 __pfx_ldsem_down_read+0x10/0x10 drivers/tty/tty_ldsem.c:338 __pfx_do_vfs_ioctl+0x10/0x10 fs/ioctl.c:805 tty_ioctl+0x643/0x1100 drivers/tty/tty_io.c:2818 Allocated by task 65: gsm_data_alloc.constprop.0+0x27/0x190 drivers/tty/n_gsm.c:926 [n_gsm] gsm_send+0x2c/0x580 drivers/tty/n_gsm.c:819 [n_gsm] gsm1_receive+0x547/0xad0 drivers/tty/n_gsm.c:3038 [n_gsm] gsmld_receive_buf+0x176/0x280 drivers/tty/n_gsm.c:3609 [n_gsm] tty_ldisc_receive_buf+0x101/0x1e0 drivers/tty/tty_buffer.c:391 tty_port_default_receive_buf+0x61/0xa0 drivers/tty/tty_port.c:39 flush_to_ldisc+0x1b0/0x750 drivers/tty/tty_buffer.c:445 process_scheduled_works+0x2b0/0x10d0 kernel/workqueue.c:3229 worker_thread+0x3dc/0x950 kernel/workqueue.c:3391 kthread+0x2a3/0x370 kernel/kthread.c:389 ret_from_fork+0x2d/0x70 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:257 Freed by task 3367: kfree+0x126/0x420 mm/slub.c:4580 gsm_cleanup_mux+0x36c/0x7b0 drivers/tty/n_gsm.c:3160 [n_gsm] gsmld_ioctl+0x395/0x1450 drivers/tty/n_gsm.c:3408 [n_gsm] tty_ioctl+0x643/0x1100 drivers/tty/tty_io.c:2818 [Analysis] gsm_msg on the tx_ctrl_list or tx_data_list of gsm_mux can be freed by multi threads through ioctl,which leads to the occurrence of uaf. Protect it by gsm tx lock. Signed-off-by: Longlong Xia <xialonglong@kylinos.cn> Cc: stable <stable@kernel.org> Suggested-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20240926130213.531959-1-xialonglong@kylinos.cn Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-22serial: imx: Update mctrl old_status on RTSD interruptMarek Vasut1-0/+15
commit 40d7903386df4d18f04d90510ba90eedee260085 upstream. 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 <stable@kernel.org> Reviewed-by: Esben Haabendal <esben@geanix.com> Signed-off-by: Marek Vasut <marex@denx.de> Link: https://lore.kernel.org/r/20241002184133.19427-1-marex@denx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-22vt: prevent kernel-infoleak in con_font_get()Jeongjun Park1-1/+1
commit f956052e00de211b5c9ebaa1958366c23f82ee9e upstream. font.data may not initialize all memory spaces depending on the implementation of vc->vc_sw->con_font_get. This may cause info-leak, so to prevent this, it is safest to modify it to initialize the allocated memory space to 0, and it generally does not affect the overall performance of the system. Cc: stable@vger.kernel.org Reported-by: syzbot+955da2d57931604ee691@syzkaller.appspotmail.com Fixes: 05e2600cb0a4 ("VT: Bump font size limitation to 64x128 pixels") Signed-off-by: Jeongjun Park <aha310510@gmail.com> Link: https://lore.kernel.org/r/20241010174619.59662-1-aha310510@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-17serial: protect uart_port_dtr_rts() in uart_shutdown() tooJiri Slaby (SUSE)1-7/+9
[ Upstream commit 602babaa84d627923713acaf5f7e9a4369e77473 ] Commit af224ca2df29 (serial: core: Prevent unsafe uart port access, part 3) added few uport == NULL checks. It added one to uart_shutdown(), so the commit assumes, uport can be NULL in there. But right after that protection, there is an unprotected "uart_port_dtr_rts(uport, false);" call. That is invoked only if HUPCL is set, so I assume that is the reason why we do not see lots of these reports. Or it cannot be NULL at this point at all for some reason :P. Until the above is investigated, stay on the safe side and move this dereference to the if too. I got this inconsistency from Coverity under CID 1585130. Thanks. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20240805102046.307511-3-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-10-04serial: qcom-geni: fix console corruptionJohan Hovold1-23/+22
[ Upstream commit cc4a0e5754a16bbc1e215c091349a7c83a2c5e14 ] The Qualcomm serial console implementation is broken and can lose characters when the serial port is also used for tty output. Specifically, the console code only waits for the current tx command to complete when all data has already been written to the fifo. When there are on-going longer transfers this often means that console output is lost when the console code inadvertently "hijacks" the current tx command instead of starting a new one. This can, for example, be observed during boot when console output that should have been interspersed with init output is truncated: [ 9.462317] qcom-snps-eusb2-hsphy fde000.phy: Registered Qcom-eUSB2 phy [ OK ] Found device KBG50ZNS256G KIOXIA Wi[ 9.471743ndows. [ 9.539915] xhci-hcd xhci-hcd.0.auto: xHCI Host Controller Add a new state variable to track how much data has been written to the fifo and use it to determine when the fifo and shift register are both empty. This is needed since there is currently no other known way to determine when the shift register is empty. This in turn allows the console code to interrupt long transfers without losing data. Note that the oops-in-progress case is similarly broken as it does not cancel any active command and also waits for the wrong status flag when attempting to drain the fifo (TX_FIFO_NOT_EMPTY_EN is only set when cancelling a command leaves data in the fifo). Fixes: c4f528795d1a ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP") Fixes: a1fee899e5be ("tty: serial: qcom_geni_serial: Fix softlock") Fixes: 9e957a155005 ("serial: qcom-geni: Don't cancel/abort if we can't get the port lock") Cc: stable@vger.kernel.org # 4.17 Reviewed-by: Douglas Anderson <dianders@chromium.org> Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Link: https://lore.kernel.org/r/20240906131336.23625-7-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-10-04serial: qcom-geni: introduce qcom_geni_serial_poll_bitfield()Douglas Anderson1-3/+9
[ Upstream commit b26d1ad1221273c88c2c4f5b4080338b8ca23859 ] With a small modification the qcom_geni_serial_poll_bit() function could be used to poll more than just a single bit. Let's generalize it. We'll make the qcom_geni_serial_poll_bit() into just a wrapper of the general function. Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org> Link: https://lore.kernel.org/r/20240610152420.v4.5.Ic6411eab8d9d37acc451705f583fb535cd6dadb2@changeid Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Link: https://lore.kernel.org/r/20240906131336.23625-6-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Stable-dep-of: cc4a0e5754a1 ("serial: qcom-geni: fix console corruption") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-10-04serial: qcom-geni: fix arg types for qcom_geni_serial_poll_bit()Douglas Anderson1-1/+1
[ Upstream commit c2eaf5e01275ae13f1ec5b1434f6c49cfff57430 ] The "offset" passed in should be unsigned since it's always a positive offset from our memory mapped IO. The "field" should be u32 since we're anding it with a 32-bit value read from the device. Suggested-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org> Link: https://lore.kernel.org/r/20240610152420.v4.4.I24a0de52dd7336908df180fa6b698e001f3aff82@changeid Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Link: https://lore.kernel.org/r/20240906131336.23625-5-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Stable-dep-of: cc4a0e5754a1 ("serial: qcom-geni: fix console corruption") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-10-04serial: qcom-geni: fix false console tx restartJohan Hovold1-10/+3
commit f97cdbbf187fefcf1fe19689cd9fdca11fe9c3eb upstream. Commit 663abb1a7a7f ("tty: serial: qcom_geni_serial: Fix UART hang") addressed an issue with stalled tx after the console code interrupted the last bytes of a tx command by reenabling the watermark interrupt if there is data in write buffer. This can however break software flow control by re-enabling tx after the user has stopped it. Address the original issue by not clearing the CMD_DONE flag after polling for command completion. This allows the interrupt handler to start another transfer when the CMD_DONE interrupt has not been disabled due to flow control. Fixes: c4f528795d1a ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP") Fixes: 663abb1a7a7f ("tty: serial: qcom_geni_serial: Fix UART hang") Cc: stable@vger.kernel.org # 4.17 Reviewed-by: Douglas Anderson <dianders@chromium.org> Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Link: https://lore.kernel.org/r/20240906131336.23625-3-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-04serial: qcom-geni: fix fifo polling timeoutJohan Hovold1-14/+17
commit c80ee36ac8f9e9c27d8e097a2eaaf198e7534c83 upstream. The qcom_geni_serial_poll_bit() can be used to wait for events like command completion and is supposed to wait for the time it takes to clear a full fifo before timing out. As noted by Doug, the current implementation does not account for start, stop and parity bits when determining the timeout. The helper also does not currently account for the shift register and the two-word intermediate transfer register. A too short timeout can specifically lead to lost characters when waiting for a transfer to complete as the transfer is cancelled on timeout. Instead of determining the poll timeout on every call, store the fifo timeout when updating it in set_termios() and make sure to take the shift and intermediate registers into account. Note that serial core has already added a 20 ms margin to the fifo timeout. Also note that the current uart_fifo_timeout() interface does unnecessary calculations on every call and did not exist in earlier kernels so only store its result once. This facilitates backports too as earlier kernels can derive the timeout from uport->timeout, which has since been removed. Fixes: c4f528795d1a ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP") Cc: stable@vger.kernel.org # 4.17 Reported-by: Douglas Anderson <dianders@chromium.org> Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Link: https://lore.kernel.org/r/20240906131336.23625-2-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-04serial: don't use uninitialized value in uart_poll_init()Jiri Slaby (SUSE)1-7/+6
commit d0009a32c9e4e083358092f3c97e3c6e803a8930 upstream. Coverity reports (as CID 1536978) that uart_poll_init() passes uninitialized pm_state to uart_change_pm(). It is in case the first 'if' takes the true branch (does "goto out;"). Fix this and simplify the function by simple guard(mutex). The code needs no labels after this at all. And it is pretty clear that the code has not fiddled with pm_state at that point. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Fixes: 5e227ef2aa38 (serial: uart_poll_init() should power on the UART) Cc: stable@vger.kernel.org Cc: Douglas Anderson <dianders@chromium.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20240805102046.307511-4-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-04tty: rp2: Fix reset with non forgiving PCIe host bridgesFlorian Fainelli1-1/+1
commit f16dd10ba342c429b1e36ada545fb36d4d1f0e63 upstream. The write to RP2_GLOBAL_CMD followed by an immediate read of RP2_GLOBAL_CMD in rp2_reset_asic() is intented to flush out the write, however by then the device is already in reset and cannot respond to a memory cycle access. On platforms such as the Raspberry Pi 4 and others using the pcie-brcmstb.c driver, any memory access to a device that cannot respond is met with a fatal system error, rather than being substituted with all 1s as is usually the case on PC platforms. Swapping the delay and the read ensures that the device has finished resetting before we attempt to read from it. Fixes: 7d9f49afa451 ("serial: rp2: New driver for Comtrol RocketPort 2 cards") Cc: stable <stable@kernel.org> Suggested-by: Jim Quinlan <james.quinlan@broadcom.com> Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com> Link: https://lore.kernel.org/r/20240906225435.707837-1-florian.fainelli@broadcom.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-04serial: 8250: omap: Cleanup on error in request_irqMarkus Schneider-Pargmann1-1/+1
[ Upstream commit 35e648a16018b747897be2ccc3ce95ff23237bb5 ] If devm_request_irq fails, the code does not cleanup many things that were setup before. Instead of directly returning ret we should jump to err. Fixes: fef4f600319e ("serial: 8250: omap: Fix life cycle issues for interrupt handlers") Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com> Reviewed-by: Kevin Hilman <khilman@baylibre.com> Tested-by: Kevin Hilman <khilman@baylibre.com> Link: https://lore.kernel.org/r/20240807141227.1093006-4-msp@baylibre.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-15Revert "serial: 8250_omap: Set the console genpd always on if no console ↵Griffin Kroah-Hartman1-28/+5
suspend" This reverts commit 68e6939ea9ec3d6579eadeab16060339cdeaf940. Kevin reported that this causes a crash during suspend on platforms that dont use PM domains. Link: https://lore.kernel.org/r/7ha5hgpchq.fsf@baylibre.com Cc: Thomas Richard <thomas.richard@bootlin.com> Fixes: 68e6939ea9ec ("serial: 8250_omap: Set the console genpd always on if no console suspend") Cc: stable <stable@kernel.org> Reported-by: Kevin Hilman <khilman@kernel.org> Signed-off-by: Griffin Kroah-Hartman <griffin@kroah.com> Link: https://lore.kernel.org/r/20240814111747.82371-1-griffin@kroah.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-13tty: atmel_serial: use the correct RTS flag.Mathieu Othacehe1-1/+1
In RS485 mode, the RTS pin is driven high by hardware when the transmitter is operating. This behaviour cannot be changed. This means that the driver should claim that it supports SER_RS485_RTS_ON_SEND and not SER_RS485_RTS_AFTER_SEND. Otherwise, when configuring the port with the SER_RS485_RTS_ON_SEND, one get the following warning: kern.warning kernel: atmel_usart_serial atmel_usart_serial.2.auto: ttyS1 (1): invalid RTS setting, using RTS_AFTER_SEND instead which is contradictory with what's really happening. Signed-off-by: Mathieu Othacehe <othacehe@gnu.org> Cc: stable <stable@kernel.org> Tested-by: Alexander Dahl <ada@thorsis.com> Fixes: af47c491e3c7 ("serial: atmel: Fill in rs485_supported") Link: https://lore.kernel.org/r/20240808060637.19886-1-othacehe@gnu.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-13tty: vt: conmakehash: remove non-portable code printing comment headerMasahiro Yamada1-10/+2
Commit 6e20753da6bc ("tty: vt: conmakehash: cope with abs_srctree no longer in env") included <linux/limits.h>, which invoked another (wrong) patch that tried to address a build error on macOS. According to the specification [1], the correct header to use PATH_MAX is <limits.h>. The minimal fix would be to replace <linux/limits.h> with <limits.h>. However, the following commits seem questionable to me: - 3bd85c6c97b2 ("tty: vt: conmakehash: Don't mention the full path of the input in output") - 6e20753da6bc ("tty: vt: conmakehash: cope with abs_srctree no longer in env") These commits made too many efforts to cope with a comment header in drivers/tty/vt/consolemap_deftbl.c: /* * Do not edit this file; it was automatically generated by * * conmakehash drivers/tty/vt/cp437.uni > [this file] * */ With this commit, the header part of the generate C file will be simplified as follows: /* * Automatically generated file; Do not edit. */ BTW, another series of excessive efforts for a comment header can be seen in the following: - 5ef6dc08cfde ("lib/build_OID_registry: don't mention the full path of the script in output") - 2fe29fe94563 ("lib/build_OID_registry: avoid non-destructive substitution for Perl < 5.13.2 compat") [1]: https://pubs.opengroup.org/onlinepubs/009695399/basedefs/limits.h.html Fixes: 6e20753da6bc ("tty: vt: conmakehash: cope with abs_srctree no longer in env") Cc: stable <stable@kernel.org> Reported-by: Daniel Gomez <da.gomez@samsung.com> Closes: https://lore.kernel.org/all/20240807-macos-build-support-v1-11-4cd1ded85694@samsung.com/ Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20240809160853.1269466-1-masahiroy@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-13tty: serial: fsl_lpuart: mark last busy before uart_add_one_portPeng Fan1-0/+1
With "earlycon initcall_debug=1 loglevel=8" in bootargs, kernel sometimes boot hang. It is because normal console still is not ready, but runtime suspend is called, so early console putchar will hang in waiting TRDE set in UARTSTAT. The lpuart driver has auto suspend delay set to 3000ms, but during uart_add_one_port, a child device serial ctrl will added and probed with its pm runtime enabled(see serial_ctrl.c). The runtime suspend call path is: device_add |-> bus_probe_device |->device_initial_probe |->__device_attach |-> pm_runtime_get_sync(dev->parent); |-> pm_request_idle(dev); |-> pm_runtime_put(dev->parent); So in the end, before normal console ready, the lpuart get runtime suspended. And earlycon putchar will hang. To address the issue, mark last busy just after pm_runtime_enable, three seconds is long enough to switch from bootconsole to normal console. Fixes: 43543e6f539b ("tty: serial: fsl_lpuart: Add runtime pm support") Cc: stable <stable@kernel.org> Signed-off-by: Peng Fan <peng.fan@nxp.com> Link: https://lore.kernel.org/r/20240808140325.580105-1-peng.fan@oss.nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-31tty: vt: conmakehash: cope with abs_srctree no longer in envMax Krummenacher1-13/+7
conmakehash uses getenv("abs_srctree") from the environment to strip the absolute path from the generated sources. However since commit e2bad142bb3d ("kbuild: unexport abs_srctree and abs_objtree") this environment variable no longer gets set. Instead use basename() to indicate the used file in a comment of the generated source file. Fixes: 3bd85c6c97b2 ("tty: vt: conmakehash: Don't mention the full path of the input in output") Cc: stable <stable@kernel.org> Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com> Link: https://lore.kernel.org/stable/20240725132056.9151-1-max.oss.09%40gmail.com Link: https://lore.kernel.org/r/20240725132056.9151-1-max.oss.09@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-31serial: sc16is7xx: fix invalid FIFO access with special register setHugo Villeneuve1-0/+4
When enabling access to the special register set, Receiver time-out and RHR interrupts can happen. In this case, the IRQ handler will try to read from the FIFO thru the RHR register at address 0x00, but address 0x00 is mapped to DLL register, resulting in erroneous FIFO reading. Call graph example: sc16is7xx_startup(): entry sc16is7xx_ms_proc(): entry sc16is7xx_set_termios(): entry sc16is7xx_set_baud(): DLH/DLL = $009C --> access special register set sc16is7xx_port_irq() entry --> IIR is 0x0C sc16is7xx_handle_rx() entry sc16is7xx_fifo_read(): --> unable to access FIFO (RHR) because it is mapped to DLL (LCR=LCR_CONF_MODE_A) sc16is7xx_set_baud(): exit --> Restore access to general register set Fix the problem by claiming the efr_lock mutex when accessing the Special register set. Fixes: dfeae619d781 ("serial: sc16is7xx") Cc: stable@vger.kernel.org Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20240723125302.1305372-3-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-31serial: sc16is7xx: fix TX fifo corruptionHugo Villeneuve1-10/+11
Sometimes, when a packet is received on channel A at almost the same time as a packet is about to be transmitted on channel B, we observe with a logic analyzer that the received packet on channel A is transmitted on channel B. In other words, the Tx buffer data on channel B is corrupted with data from channel A. The problem appeared since commit 4409df5866b7 ("serial: sc16is7xx: change EFR lock to operate on each channels"), which changed the EFR locking to operate on each channel instead of chip-wise. This commit has introduced a regression, because the EFR lock is used not only to protect the EFR registers access, but also, in a very obscure and undocumented way, to protect access to the data buffer, which is shared by the Tx and Rx handlers, but also by each channel of the IC. Fix this regression first by switching to kfifo_out_linear_ptr() in sc16is7xx_handle_tx() to eliminate the need for a shared Rx/Tx buffer. Secondly, replace the chip-wise Rx buffer with a separate Rx buffer for each channel. Fixes: 4409df5866b7 ("serial: sc16is7xx: change EFR lock to operate on each channels") Cc: stable@vger.kernel.org Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20240723125302.1305372-2-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-31serial: core: check uartclk for zero to avoid divide by zeroGeorge Kennedy1-0/+8
Calling ioctl TIOCSSERIAL with an invalid baud_base can result in uartclk being zero, which will result in a divide by zero error in uart_get_divisor(). The check for uartclk being zero in uart_set_info() needs to be done before other settings are made as subsequent calls to ioctl TIOCSSERIAL for the same port would be impacted if the uartclk check was done where uartclk gets set. Oops: divide error: 0000 PREEMPT SMP KASAN PTI RIP: 0010:uart_get_divisor (drivers/tty/serial/serial_core.c:580) Call Trace: <TASK> serial8250_get_divisor (drivers/tty/serial/8250/8250_port.c:2576 drivers/tty/serial/8250/8250_port.c:2589) serial8250_do_set_termios (drivers/tty/serial/8250/8250_port.c:502 drivers/tty/serial/8250/8250_port.c:2741) serial8250_set_termios (drivers/tty/serial/8250/8250_port.c:2862) uart_change_line_settings (./include/linux/spinlock.h:376 ./include/linux/serial_core.h:608 drivers/tty/serial/serial_core.c:222) uart_port_startup (drivers/tty/serial/serial_core.c:342) uart_startup (drivers/tty/serial/serial_core.c:368) uart_set_info (drivers/tty/serial/serial_core.c:1034) uart_set_info_user (drivers/tty/serial/serial_core.c:1059) tty_set_serial (drivers/tty/tty_io.c:2637) tty_ioctl (drivers/tty/tty_io.c:2647 drivers/tty/tty_io.c:2791) __x64_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:907 fs/ioctl.c:893 fs/ioctl.c:893) do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1) arch/x86/entry/common.c:83 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Reported-by: syzkaller <syzkaller@googlegroups.com> Cc: stable@vger.kernel.org Signed-off-by: George Kennedy <george.kennedy@oracle.com> Rule: add Link: https://lore.kernel.org/stable/1721148848-9784-1-git-send-email-george.kennedy%40oracle.com Link: https://lore.kernel.org/r/1721219078-3209-1-git-send-email-george.kennedy@oracle.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-27Merge tag 'devicetree-fixes-for-6.11-1' of ↵Linus Torvalds1-3/+1
git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux Pull more devicetree updates from Rob Herring: "Most of this is a treewide change to of_property_for_each_u32() which was small enough to do in one go before rc1 and avoids the need to create of_property_for_each_u32_some_new_name(). - Treewide conversion of of_property_for_each_u32() to drop internal arguments making struct property opaque - Add binding for Amlogic A4 SoC watchdog - Fix constraints for AD7192 'single-channel' property" * tag 'devicetree-fixes-for-6.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: dt-bindings: iio: adc: ad7192: Fix 'single-channel' constraints of: remove internal arguments from of_property_for_each_u32() dt-bindings: watchdog: add support for Amlogic A4 SoCs
2024-07-25Merge tag 'printk-for-6.11-trivial' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull printk updates from Petr Mladek: - trivial printk changes The bigger "real" printk work is still being discussed. * tag 'printk-for-6.11-trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: vsprintf: add missing MODULE_DESCRIPTION() macro printk: Rename console_replay_all() and update context
2024-07-25Merge tag 'driver-core-6.11-rc1' of ↵Linus Torvalds2-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here is the big set of driver core changes for 6.11-rc1. Lots of stuff in here, with not a huge diffstat, but apis are evolving which required lots of files to be touched. Highlights of the changes in here are: - platform remove callback api final fixups (Uwe took many releases to get here, finally!) - Rust bindings for basic firmware apis and initial driver-core interactions. It's not all that useful for a "write a whole driver in rust" type of thing, but the firmware bindings do help out the phy rust drivers, and the driver core bindings give a solid base on which others can start their work. There is still a long way to go here before we have a multitude of rust drivers being added, but it's a great first step. - driver core const api changes. This reached across all bus types, and there are some fix-ups for some not-common bus types that linux-next and 0-day testing shook out. This work is being done to help make the rust bindings more safe, as well as the C code, moving toward the end-goal of allowing us to put driver structures into read-only memory. We aren't there yet, but are getting closer. - minor devres cleanups and fixes found by code inspection - arch_topology minor changes - other minor driver core cleanups All of these have been in linux-next for a very long time with no reported problems" * tag 'driver-core-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (55 commits) ARM: sa1100: make match function take a const pointer sysfs/cpu: Make crash_hotplug attribute world-readable dio: Have dio_bus_match() callback take a const * zorro: make match function take a const pointer driver core: module: make module_[add|remove]_driver take a const * driver core: make driver_find_device() take a const * driver core: make driver_[create|remove]_file take a const * firmware_loader: fix soundness issue in `request_internal` firmware_loader: annotate doctests as `no_run` devres: Correct code style for functions that return a pointer type devres: Initialize an uninitialized struct member devres: Fix memory leakage caused by driver API devm_free_percpu() devres: Fix devm_krealloc() wasting memory driver core: platform: Switch to use kmemdup_array() driver core: have match() callback in struct bus_type take a const * MAINTAINERS: add Rust device abstractions to DRIVER CORE device: rust: improve safety comments MAINTAINERS: add Danilo as FIRMWARE LOADER maintainer MAINTAINERS: add Rust FW abstractions to FIRMWARE LOADER firmware: rust: improve safety comments ...
2024-07-25of: remove internal arguments from of_property_for_each_u32()Luca Ceresoli1-3/+1
The of_property_for_each_u32() macro needs five parameters, two of which are primarily meant as internal variables for the macro itself (in the for() clause). Yet these two parameters are used by a few drivers, and this can be considered misuse or at least bad practice. Now that the kernel uses C11 to build, these two parameters can be avoided by declaring them internally, thus changing this pattern: struct property *prop; const __be32 *p; u32 val; of_property_for_each_u32(np, "xyz", prop, p, val) { ... } to this: u32 val; of_property_for_each_u32(np, "xyz", val) { ... } However two variables cannot be declared in the for clause even with C11, so declare one struct that contain the two variables we actually need. As the variables inside this struct are not meant to be used by users of this macro, give the struct instance the noticeable name "_it" so it is visible during code reviews, helping to avoid new code to use it directly. Most usages are trivially converted as they do not use those two parameters, as expected. The non-trivial cases are: - drivers/clk/clk.c, of_clk_get_parent_name(): easily doable anyway - drivers/clk/clk-si5351.c, si5351_dt_parse(): this is more complex as the checks had to be replicated in a different way, making code more verbose and somewhat uglier, but I refrained from a full rework to keep as much of the original code untouched having no hardware to test my changes All the changes have been build tested. The few for which I have the hardware have been runtime-tested too. Reviewed-by: Andre Przywara <andre.przywara@arm.com> # drivers/clk/sunxi/clk-simple-gates.c, drivers/clk/sunxi/clk-sun8i-bus-gates.c Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> # drivers/gpio/gpio-brcmstb.c Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com> # drivers/irqchip/irq-atmel-aic-common.c Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # drivers/iio/adc/ti_am335x_adc.c Acked-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com> # drivers/pwm/pwm-samsung.c Acked-by: Richard Leitner <richard.leitner@linux.dev> # drivers/usb/misc/usb251xb.c Acked-by: Mark Brown <broonie@kernel.org> # sound/soc/codecs/arizona.c Reviewed-by: Richard Fitzgerald <rf@opensource.cirrus.com> # sound/soc/codecs/arizona.c Acked-by: Michael Ellerman <mpe@ellerman.id.au> # arch/powerpc/sysdev/xive/spapr.c Acked-by: Stephen Boyd <sboyd@kernel.org> # clk Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com> Acked-by: Lee Jones <lee@kernel.org> Link: https://lore.kernel.org/r/20240724-of_property_for_each_u32-v3-1-bea82ce429e2@bootlin.com Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
2024-07-19Merge tag 'tty-6.11-rc1' of ↵Linus Torvalds29-510/+697
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty / serial updates from Greg KH: "Here is a small set of tty and serial driver updates for 6.11-rc1. Not much happened this cycle, unlike the previous kernel release which had lots of "excitement" in this part of the kernel. Included in here are the following changes: - dt binding updates for new platforms - 8250 driver updates - various small serial driver fixes and updates - printk/console naming and matching attempt #2 (was reverted for 6.10-final, should be good to go this time around, acked by the relevant maintainers). All of these have been in linux-next for a while with no reported issues" * tag 'tty-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (22 commits) Documentation: kernel-parameters: Add DEVNAME:0.0 format for serial ports serial: core: Add serial_base_match_and_update_preferred_console() printk: Add match_devname_and_update_preferred_console() serial: sc16is7xx: hardware reset chip if reset-gpios is defined in DT dt-bindings: serial: sc16is7xx: add reset-gpios dt-bindings: serial: vt8500-uart: convert to json-schema serial: 8250_platform: Explicitly show we initialise ISA ports only once tty: add missing MODULE_DESCRIPTION() macros dt-bindings: serial: mediatek,uart: add MT7988 serial: sh-sci: Add support for RZ/V2H(P) SoC dt-bindings: serial: Add documentation for Renesas RZ/V2H(P) (R9A09G057) SCIF support dt-bindings: serial: renesas,scif: Make 'interrupt-names' property as required dt-bindings: serial: renesas,scif: Validate 'interrupts' and 'interrupt-names' dt-bindings: serial: renesas,scif: Move ref for serial.yaml at the end riscv: dts: starfive: jh7110: Add the core reset and jh7110 compatible for uarts serial: 8250_dw: Use reset array API to get resets dt-bindings: serial: snps-dw-apb-uart: Add one more reset signal for StarFive JH7110 SoC serial: 8250: Extract platform driver serial: 8250: Extract RSA bits serial: imx: stop casting struct uart_port to struct imx_port ...
2024-07-04serial: core: Add serial_base_match_and_update_preferred_console()Tony Lindgren3-0/+57
Let's add serial_base_match_and_update_preferred_console() for consoles using DEVNAME:0.0 style naming. The earlier approach to add it caused issues in the kernel command line ordering as we were calling __add_preferred_console() again for the deferred consoles. Signed-off-by: Tony Lindgren <tony.lindgren@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Tested-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20240703100615.118762-3-tony.lindgren@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-04serial: qcom-geni: do not kill the machine on fifo underrunJohan Hovold1-1/+1
The Qualcomm GENI serial driver did not handle buffer flushing and used to print discarded characters when the circular buffer was cleared. Since commit 1788cf6a91d9 ("tty: serial: switch from circ_buf to kfifo") this instead resulted in a hard lockup due to qcom_geni_serial_send_chunk_fifo() spinning indefinitely in the interrupt handler. The underlying bugs have now been fixed, but make sure to output NUL characters instead of killing the machine if a similar driver bug is ever reintroduced. Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Link: https://lore.kernel.org/r/20240704101805.30612-4-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-04serial: qcom-geni: fix hard lockup on buffer flushJohan Hovold1-3/+13
The Qualcomm GENI serial driver does not handle buffer flushing and used to continue printing discarded characters when the circular buffer was cleared. Since commit 1788cf6a91d9 ("tty: serial: switch from circ_buf to kfifo") this instead results in a hard lockup due to qcom_geni_serial_send_chunk_fifo() spinning indefinitely in the interrupt handler. This is easily triggered by interrupting a command such as dmesg in a serial console but can also happen when stopping a serial getty on reboot. Implement the flush_buffer() callback and use it to cancel any active TX command when the write buffer has been emptied. Reported-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/lkml/20240610222515.3023730-1-dianders@chromium.org/ Fixes: 1788cf6a91d9 ("tty: serial: switch from circ_buf to kfifo") Fixes: a1fee899e5be ("tty: serial: qcom_geni_serial: Fix softlock") Cc: stable@vger.kernel.org # 5.0 Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Link: https://lore.kernel.org/r/20240704101805.30612-3-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-04serial: qcom-geni: fix soft lockup on sw flow control and suspendJohan Hovold1-9/+24
The stop_tx() callback is used to implement software flow control and must not discard data as the Qualcomm GENI driver is currently doing when there is an active TX command. Cancelling an active command can also leave data in the hardware FIFO, which prevents the watermark interrupt from being enabled when TX is later restarted. This results in a soft lockup and is easily triggered by stopping TX using software flow control in a serial console but this can also happen after suspend. Fix this by only stopping any active command, and effectively clearing the hardware fifo, when shutting down the port. When TX is later restarted, a transfer command may need to be issued to discard any stale data that could prevent the watermark interrupt from firing. Fixes: c4f528795d1a ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP") Cc: stable@vger.kernel.org # 4.17 Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Link: https://lore.kernel.org/r/20240704101805.30612-2-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-03serial: imx: ensure RTS signal is not left active after shutdownRasmus Villemoes1-0/+51
If a process is killed while writing to a /dev/ttymxc* device in RS485 mode, we observe that the RTS signal is left high, thus making it impossible for other d