summaryrefslogtreecommitdiff
path: root/drivers/tty/serial
AgeCommit message (Collapse)AuthorFilesLines
2021-12-08serial: 8250: Fix RTS modem control while in rs485 modeLukas Wunner2-7/+5
commit f85e04503f369b3f2be28c83fc48b74e19936ebc upstream. Commit f45709df7731 ("serial: 8250: Don't touch RTS modem control while in rs485 mode") sought to prevent user space from interfering with rs485 communication by ignoring a TIOCMSET ioctl() which changes RTS polarity. It did so in serial8250_do_set_mctrl(), which turns out to be too deep in the call stack: When a uart_port is opened, RTS polarity is set by the rs485-aware function uart_port_dtr_rts(). It calls down to serial8250_do_set_mctrl() and that particular RTS polarity change should *not* be ignored. The user-visible result is that on 8250_omap ports which use rs485 with inverse polarity (RTS bit in MCR register is 1 to receive, 0 to send), a newly opened port initially sets up RTS for sending instead of receiving. That's because omap_8250_startup() sets the cached value up->mcr to 0 and omap_8250_restore_regs() subsequently writes it to the MCR register. Due to the commit, serial8250_do_set_mctrl() preserves that incorrect register value: do_sys_openat2 do_filp_open path_openat vfs_open do_dentry_open chrdev_open tty_open uart_open tty_port_open uart_port_activate uart_startup uart_port_startup serial8250_startup omap_8250_startup # up->mcr = 0 uart_change_speed serial8250_set_termios omap_8250_set_termios omap_8250_restore_regs serial8250_out_MCR # up->mcr written tty_port_block_til_ready uart_dtr_rts uart_port_dtr_rts serial8250_set_mctrl omap8250_set_mctrl serial8250_do_set_mctrl # mcr[1] = 1 ignored Fix by intercepting RTS changes from user space in uart_tiocmset() instead. Link: https://lore.kernel.org/linux-serial/20211027111644.1996921-1-baocheng.su@siemens.com/ Fixes: f45709df7731 ("serial: 8250: Don't touch RTS modem control while in rs485 mode") Cc: Chao Zeng <chao.zeng@siemens.com> Cc: stable@vger.kernel.org # v5.7+ Reported-by: Su Bao Cheng <baocheng.su@siemens.com> Reported-by: Jan Kiszka <jan.kiszka@siemens.com> Tested-by: Su Bao Cheng <baocheng.su@siemens.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/21170e622a1aaf842a50b32146008b5374b3dd1d.1637596432.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08serial: 8250_pci: rewrite pericom_do_set_divisor()Jay Dolan1-13/+17
commit bb1201d4b38ec67bd9a871cf86b0cc10f28b15b5 upstream. Have pericom_do_set_divisor() use the uartclk instead of a hard coded value to work with different speed crystals. Tested with 14.7456 and 24 MHz crystals. Have pericom_do_set_divisor() always calculate the divisor rather than call serial8250_do_set_divisor() for rates below baud_base. Do not write registers or call serial8250_do_set_divisor() if valid divisors could not be found. Fixes: 6bf4e42f1d19 ("serial: 8250: Add support for higher baud rates to Pericom chips") Cc: stable <stable@vger.kernel.org> Signed-off-by: Jay Dolan <jay.dolan@accesio.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20211122120604.3909-3-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08serial: 8250_pci: Fix ACCES entries in pci_serial_quirks arrayJay Dolan1-1/+8
commit c525c5d2437f93520388920baac6d9340c65d239 upstream. Fix error in table for PCI_DEVICE_ID_ACCESIO_PCIE_ICM_4S that caused it and PCI_DEVICE_ID_ACCESIO_PCIE_ICM232_4 to be missing their fourth port. Fixes: 78d3820b9bd3 ("serial: 8250_pci: Have ACCES cards that use the four port Pericom PI7C9X7954 chip use the pci_pericom_setup()") Cc: stable <stable@vger.kernel.org> Signed-off-by: Jay Dolan <jay.dolan@accesio.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20211122120604.3909-2-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08serial: core: fix transmit-buffer reset and memleakJohan Hovold1-1/+12
commit 00de977f9e0aa9760d9a79d1e41ff780f74e3424 upstream. Commit 761ed4a94582 ("tty: serial_core: convert uart_close to use tty_port_close") converted serial core to use tty_port_close() but failed to notice that the transmit buffer still needs to be freed on final close. Not freeing the transmit buffer means that the buffer is no longer cleared on next open so that any ioctl() waiting for the buffer to drain might wait indefinitely (e.g. on termios changes) or that stale data can end up being transmitted in case tx is restarted. Furthermore, the buffer of any port that has been opened would leak on driver unbind. Note that the port lock is held when clearing the buffer pointer due to the ldisc race worked around by commit a5ba1d95e46e ("uart: fix race between uart_put_char() and uart_shutdown()"). Also note that the tty-port shutdown() callback is not called for console ports so it is not strictly necessary to free the buffer page after releasing the lock (cf. d72402145ace ("tty/serial: do not free trasnmit buffer page under port lock")). Link: https://lore.kernel.org/r/319321886d97c456203d5c6a576a5480d07c3478.1635781688.git.baruch@tkos.co.il Fixes: 761ed4a94582 ("tty: serial_core: convert uart_close to use tty_port_close") Cc: stable@vger.kernel.org # 4.9 Cc: Rob Herring <robh@kernel.org> Reported-by: Baruch Siach <baruch@tkos.co.il> Tested-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20211108085431.12637-1-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08serial: tegra: Change lower tolerance baud rate limit for tegra20 and tegra30Patrik John1-2/+2
commit b40de7469ef135161c80af0e8c462298cc5dac00 upstream. The current implementation uses 0 as lower limit for the baud rate tolerance for tegra20 and tegra30 chips which causes isses on UART initialization as soon as baud rate clock is lower than required even when within the standard UART tolerance of +/- 4%. This fix aligns the implementation with the initial commit description of +/- 4% tolerance for tegra chips other than tegra186 and tegra194. Fixes: d781ec21bae6 ("serial: tegra: report clk rate errors") Cc: stable <stable@vger.kernel.org> Signed-off-by: Patrik John <patrik.john@u-blox.com> Link: https://lore.kernel.org/r/sig.19614244f8.20211123132737.88341-1-patrik.john@u-blox.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08serial: pl011: Add ACPI SBSA UART match idPierre Gondois1-0/+1
commit ac442a077acf9a6bf1db4320ec0c3f303be092b3 upstream. The document 'ACPI for Arm Components 1.0' defines the following _HID mappings: -'Prime cell UART (PL011)': ARMH0011 -'SBSA UART': ARMHB000 Use the sbsa-uart driver when a device is described with the 'ARMHB000' _HID. Note: PL011 devices currently use the sbsa-uart driver instead of the uart-pl011 driver. Indeed, PL011 devices are not bound to a clock in ACPI. It is not possible to change their baudrate. Cc: <stable@vger.kernel.org> Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com> Link: https://lore.kernel.org/r/20211109172248.19061-1-Pierre.Gondois@arm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08tty: serial: msm_serial: Deactivate RX DMA for polling supportSven Eckelmann1-0/+3
commit 7492ffc90fa126afb67d4392d56cb4134780194a upstream. The CONSOLE_POLLING mode is used for tools like k(g)db. In this kind of setup, it is often sharing a serial device with the normal system console. This is usually no problem because the polling helpers can consume input values directly (when in kgdb context) and the normal Linux handlers can only consume new input values after kgdb switched back. This is not true anymore when RX DMA is enabled for UARTDM controllers. Single input values can no longer be received correctly. Instead following seems to happen: * on 1. input, some old input is read (continuously) * on 2. input, two old inputs are read (continuously) * on 3. input, three old input values are read (continuously) * on 4. input, 4 previous inputs are received This repeats then for each group of 4 input values. This behavior changes slightly depending on what state the controller was when the first input was received. But this makes working with kgdb basically impossible because control messages are always corrupted when kgdboc tries to parse them. RX DMA should therefore be off when CONSOLE_POLLING is enabled to avoid these kind of problems. No such problem was noticed for TX DMA. Fixes: 99693945013a ("tty: serial: msm: Add RX DMA support") Cc: stable@vger.kernel.org Signed-off-by: Sven Eckelmann <sven@narfation.org> Link: https://lore.kernel.org/r/20211113121050.7266-1-sven@narfation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-18serial: xilinx_uartps: Fix race condition causing stuck TXAnssi Hannula1-1/+2
[ Upstream commit 88b20f84f0fe47409342669caf3e58a3fc64c316 ] xilinx_uartps .start_tx() clears TXEMPTY when enabling TXEMPTY to avoid any previous TXEVENT event asserting the UART interrupt. This clear operation is done immediately after filling the TX FIFO. However, if the bytes inserted by cdns_uart_handle_tx() are consumed by the UART before the TXEMPTY is cleared, the clear operation eats the new TXEMPTY event as well, causing cdns_uart_isr() to never receive the TXEMPTY event. If there are bytes still queued in circbuf, TX will get stuck as they will never get transferred to FIFO (unless new bytes are queued to circbuf in which case .start_tx() is called again). While the racy missed TXEMPTY occurs fairly often with short data sequences (e.g. write 1 byte), in those cases circbuf is usually empty so no action on TXEMPTY would have been needed anyway. On the other hand, longer data sequences make the race much more unlikely as UART takes longer to consume the TX FIFO. Therefore it is rare for this race to cause visible issues in general. Fix the race by clearing the TXEMPTY bit in ISR *before* filling the FIFO. The TXEMPTY bit in ISR will only get asserted at the exact moment the TX FIFO *becomes* empty, so clearing the bit before filling FIFO does not cause an extra immediate assertion even if the FIFO is initially empty. This is hard to reproduce directly on a normal system, but inserting e.g. udelay(200) after cdns_uart_handle_tx(port), setting 4000000 baud, and then running "dd if=/dev/zero bs=128 of=/dev/ttyPS0 count=50" reliably reproduces the issue on my ZynqMP test system unless this fix is applied. Fixes: 85baf542d54e ("tty: xuartps: support 64 byte FIFO size") Signed-off-by: Anssi Hannula <anssi.hannula@bitwise.fi> Link: https://lore.kernel.org/r/20211026102741.2910441-1-anssi.hannula@bitwise.fi Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18serial: imx: fix detach/attach of serial consoleStefan Agner1-2/+2
[ Upstream commit 6d0d1b5a1b4870911beb89544ec1a9751c42fec7 ] If the device used as a serial console gets detached/attached at runtime, register_console() will try to call imx_uart_setup_console(), but this is not possible since it is marked as __init. For instance # cat /sys/devices/virtual/tty/console/active tty1 ttymxc0 # echo -n N > /sys/devices/virtual/tty/console/subsystem/ttymxc0/console # echo -n Y > /sys/devices/virtual/tty/console/subsystem/ttymxc0/console [ 73.166649] 8<--- cut here --- [ 73.167005] Unable to handle kernel paging request at virtual address c154d928 [ 73.167601] pgd = 55433e84 [ 73.167875] [c154d928] *pgd=8141941e(bad) [ 73.168304] Internal error: Oops: 8000000d [#1] SMP ARM [ 73.168429] Modules linked in: [ 73.168522] CPU: 0 PID: 536 Comm: sh Not tainted 5.15.0-rc6-00056-g3968ddcf05fb #3 [ 73.168675] Hardware name: Freescale i.MX6 Ultralite (Device Tree) [ 73.168791] PC is at imx_uart_console_setup+0x0/0x238 [ 73.168927] LR is at try_enable_new_console+0x98/0x124 [ 73.169056] pc : [<c154d928>] lr : [<c0196f44>] psr: a0000013 [ 73.169178] sp : c2ef5e70 ip : 00000000 fp : 00000000 [ 73.169281] r10: 00000000 r9 : c02cf970 r8 : 00000000 [ 73.169389] r7 : 00000001 r6 : 00000001 r5 : c1760164 r4 : c1e0fb08 [ 73.169512] r3 : c154d928 r2 : 00000000 r1 : efffcbd1 r0 : c1760164 [ 73.169641] Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none [ 73.169782] Control: 10c5387d Table: 8345406a DAC: 00000051 [ 73.169895] Register r0 information: non-slab/vmalloc memory [ 73.170032] Register r1 information: non-slab/vmalloc memory [ 73.170158] Register r2 information: NULL pointer [ 73.170273] Register r3 information: non-slab/vmalloc memory [ 73.170397] Register r4 information: non-slab/vmalloc memory [ 73.170521] Register r5 information: non-slab/vmalloc memory [ 73.170647] Register r6 information: non-paged memory [ 73.170771] Register r7 information: non-paged memory [ 73.170892] Register r8 information: NULL pointer [ 73.171009] Register r9 information: non-slab/vmalloc memory [ 73.171142] Register r10 information: NULL pointer [ 73.171259] Register r11 information: NULL pointer [ 73.171375] Register r12 information: NULL pointer [ 73.171494] Process sh (pid: 536, stack limit = 0xcd1ba82f) [ 73.171621] Stack: (0xc2ef5e70 to 0xc2ef6000) [ 73.171731] 5e60: ???????? ???????? ???????? ???????? [ 73.171899] 5e80: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.172059] 5ea0: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.172217] 5ec0: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.172377] 5ee0: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.172537] 5f00: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.172698] 5f20: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.172856] 5f40: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.173016] 5f60: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.173177] 5f80: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.173336] 5fa0: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.173496] 5fc0: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.173654] 5fe0: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.173826] [<c0196f44>] (try_enable_new_console) from [<c01984a8>] (register_console+0x10c/0x2ec) [ 73.174053] [<c01984a8>] (register_console) from [<c06e2c90>] (console_store+0x14c/0x168) [ 73.174262] [<c06e2c90>] (console_store) from [<c0383718>] (kernfs_fop_write_iter+0x110/0x1cc) [ 73.174470] [<c0383718>] (kernfs_fop_write_iter) from [<c02cf5f4>] (vfs_write+0x31c/0x548) [ 73.174679] [<c02cf5f4>] (vfs_write) from [<c02cf970>] (ksys_write+0x60/0xec) [ 73.174863] [<c02cf970>] (ksys_write) from [<c0100080>] (ret_fast_syscall+0x0/0x1c) [ 73.175052] Exception stack(0xc2ef5fa8 to 0xc2ef5ff0) [ 73.175167] 5fa0: ???????? ???????? ???????? ???????? ???????? ???????? [ 73.175327] 5fc0: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.175486] 5fe0: ???????? ???????? ???????? ???????? [ 73.175608] Code: 00000000 00000000 00000000 00000000 (00000000) [ 73.175744] ---[ end trace 9b75121265109bf1 ]--- A similar issue could be triggered by unbinding/binding the serial console device [*]. Drop __init so that imx_uart_setup_console() can be safely called at runtime. [*] https://lore.kernel.org/all/20181114174940.7865-3-stefan@agner.ch/ Fixes: a3cb39d258ef ("serial: core: Allow detach and attach serial device for console") Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Stefan Agner <stefan@agner.ch> Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com> Link: https://lore.kernel.org/r/20211020192643.476895-2-francesco.dolcini@toradex.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18serial: 8250_dw: Drop wrong use of ACPI_PTR()Andy Shevchenko1-1/+1
[ Upstream commit ebabb77a2a115b6c5e68f7364b598310b5f61fb2 ] ACPI_PTR() is more harmful than helpful. For example, in this case if CONFIG_ACPI=n, the ID table left unused which is not what we want. Instead of adding ifdeffery here and there, drop ACPI_PTR(). Fixes: 6a7320c4669f ("serial: 8250_dw: Add ACPI 5.0 support") Reported-by: Daniel Palmer <daniel@0x0f.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20211005134516.23218-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18serial: 8250: fix racy uartclk updateJohan Hovold1-4/+17
commit 211cde4f5817dc88ef7f8f2fa286e57fbf14c8ee upstream. Commit 868f3ee6e452 ("serial: 8250: Add 8250 port clock update method") added a hack to support SoCs where the UART reference clock can change behind the back of the driver but failed to add the proper locking. First, make sure to take a reference to the tty struct to avoid dereferencing a NULL pointer if the clock change races with a hangup. Second, the termios semaphore must be held during the update to prevent a racing termios change. Fixes: 868f3ee6e452 ("serial: 8250: Add 8250 port clock update method") Fixes: c8dff3aa8241 ("serial: 8250: Skip uninitialized TTY port baud rate update") Cc: stable@vger.kernel.org # 5.9 Cc: Serge Semin <Sergey.Semin@baikalelectronics.ru> Tested-by: Serge Semin <fancer.lancer@gmail.com> Reviewed-by: Serge Semin <fancer.lancer@gmail.com> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20211015111422.1027-2-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-18serial: core: Fix initializing and restoring termios speedPali Rohár1-2/+14
commit 027b57170bf8bb6999a28e4a5f3d78bf1db0f90c upstream. Since commit edc6afc54968 ("tty: switch to ktermios and new framework") termios speed is no longer stored only in c_cflag member but also in new additional c_ispeed and c_ospeed members. If BOTHER flag is set in c_cflag then termios speed is stored only in these new members. Therefore to correctly restore termios speed it is required to store also ispeed and ospeed members, not only cflag member. In case only cflag member with BOTHER flag is restored then functions tty_termios_baud_rate() and tty_termios_input_baud_rate() returns baudrate stored in c_ospeed / c_ispeed member, which is zero as it was not restored too. If reported baudrate is invalid (e.g. zero) then serial core functions report fallback baudrate value 9600. So it means that in this case original baudrate is lost and kernel changes it to value 9600. Simple reproducer of this issue is to boot kernel with following command line argument: "console=ttyXXX,86400" (where ttyXXX is the device name). For speed 86400 there is no Bnnn constant and therefore kernel has to represent this speed via BOTHER c_cflag. Which means that speed is stored only in c_ospeed and c_ispeed members, not in c_cflag anymore. If bootloader correctly configures serial device to speed 86400 then kernel prints boot log to early console at speed speed 86400 without any issue. But after kernel starts initializing real console device ttyXXX then speed is changed to fallback value 9600 because information about speed was lost. This patch fixes above issue by storing and restoring also ispeed and ospeed members, which are required for BOTHER flag. Fixes: edc6afc54968 ("[PATCH] tty: switch to ktermios and new framework") Cc: stable@vger.kernel.org Signed-off-by: Pali Rohár <pali@kernel.org> Link: https://lore.kernel.org/r/20211002130900.9518-1-pali@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-30serial: mvebu-uart: fix driver's tx_empty callbackPali Rohár1-1/+1
commit 74e1eb3b4a1ef2e564b4bdeb6e92afe844e900de upstream. Driver's tx_empty callback should signal when the transmit shift register is empty. So when the last character has been sent. STAT_TX_FIFO_EMP bit signals only that HW transmit FIFO is empty, which happens when the last byte is loaded into transmit shift register. STAT_TX_EMP bit signals when the both HW transmit FIFO and transmit shift register are empty. So replace STAT_TX_FIFO_EMP check by STAT_TX_EMP in mvebu_uart_tx_empty() callback function. Fixes: 30530791a7a0 ("serial: mvebu-uart: initial support for Armada-3700 serial port") Cc: stable <stable@vger.kernel.org> Signed-off-by: Pali Rohár <pali@kernel.org> Link: https://lore.kernel.org/r/20210911132017.25505-1-pali@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-30serial: 8250: 8250_omap: Fix RX_LVL register offsetNishanth Menon1-1/+1
commit 79e9e30a9292a62d25ab75488d3886108db1eaad upstream. Commit b67e830d38fa ("serial: 8250: 8250_omap: Fix possible interrupt storm on K3 SoCs") introduced fixup including a register read to RX_LVL, however, we should be using word offset than byte offset since our registers are on 4 byte boundary (port.regshift = 2) for 8250_omap. Fixes: b67e830d38fa ("serial: 8250: 8250_omap: Fix possible interrupt storm on K3 SoCs") Cc: stable <stable@vger.kernel.org> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Vignesh Raghavendra <vigneshr@ti.com> Signed-off-by: Nishanth Menon <nm@ti.com> Link: https://lore.kernel.org/r/20210903050550.29050-1-nm@ti.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-18serial: sh-sci: fix break handling for sysrqUlrich Hecht1-1/+6
[ Upstream commit 87b8061bad9bd4b549b2daf36ffbaa57be2789a2 ] This fixes two issues that cause the sysrq sequence to be inadvertently aborted on SCIF serial consoles: - a NUL character remains in the RX queue after a break has been detected, which is then passed on to uart_handle_sysrq_char() - the break interrupt is handled twice on controllers with multiplexed ERI and BRI interrupts Signed-off-by: Ulrich Hecht <uli+renesas@fpond.eu> Link: https://lore.kernel.org/r/20210816162201.28801-1-uli+renesas@fpond.eu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-18serial: 8250_omap: Handle optional overrun-throttle-ms propertyTony Lindgren1-1/+24
[ Upstream commit 1fe0e1fa3209ad8e9124147775bd27b1d9f04bd4 ] Handle optional overrun-throttle-ms property as done for 8250_fsl in commit 6d7f677a2afa ("serial: 8250: Rate limit serial port rx interrupts during input overruns"). This can be used to rate limit the UART interrupts on noisy lines that end up producing messages like the following: ttyS ttyS2: 4 input overrun(s) At least on droid4, the multiplexed USB and UART port is left to UART mode by the bootloader for a debug console, and if a USB charger is connected on boot, we get noise on the UART until the PMIC related drivers for PHY and charger are loaded. With this patch and overrun-throttle-ms = <500> we avoid the extra rx interrupts. Cc: Carl Philipp Klemm <philipp@uvos.xyz> Cc: Merlijn Wajer <merlijn@wizzup.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: Sebastian Reichel <sre@kernel.org> Cc: Vignesh Raghavendra <vigneshr@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20210727103533.51547-2-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-18serial: 8250_pci: make setup_port() parameters explicitly unsignedGreg Kroah-Hartman1-1/+1
[ Upstream commit 3a96e97ab4e835078e6f27b7e1c0947814df3841 ] The bar and offset parameters to setup_port() are used in pointer math, and while it would be very difficult to get them to wrap as a negative number, just be "safe" and make them unsigned so that static checkers do not trip over them unintentionally. Cc: Jiri Slaby <jirislaby@kernel.org> Reported-by: Jordy Zomer <jordy@pwning.systems> Link: https://lore.kernel.org/r/20210726130717.2052096-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-18serial: 8250: Define RX trigger levels for OxSemi 950 devicesMaciej W. Rozycki1-1/+2
[ Upstream commit d7aff291d069c4418285f3c8ee27b0ff67ce5998 ] Oxford Semiconductor 950 serial port devices have a 128-byte FIFO and in the enhanced (650) mode, which we select in `autoconfig_has_efr' with the ECB bit set in the EFR register, they support the receive interrupt trigger level selectable with FCR bits 7:6 from the set of 16, 32, 112, 120. This applies to the original OX16C950 discrete UART[1] as well as 950 cores embedded into more complex devices. For these devices we set the default to 112, which sets an excessively high level of 112 or 7/8 of the FIFO capacity, unlike with other port types where we choose at most 1/2 of their respective FIFO capacities. Additionally we don't make the trigger level configurable. Consequently frequent input overruns happen with high bit rates where hardware flow control cannot be used (e.g. terminal applications) even with otherwise highly-performant systems. Lower the default receive interrupt trigger level to 32 then, and make it configurable. Document the trigger levels along with other port types, including the set of 16, 32, 64, 112 for the transmit interrupt as well[2]. References: [1] "OX16C950 rev B High Performance UART with 128 byte FIFOs", Oxford Semiconductor, Inc., DS-0031, Sep 05, Table 10: "Receiver Trigger Levels", p. 22 [2] same, Table 9: "Transmit Interrupt Trigger Levels", p. 22 Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2106260608480.37803@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-18tty: serial: jsm: hold port lock when reporting modem line changesZheyu Ma2-0/+5
[ Upstream commit 240e126c28df084222f0b661321e8e3ecb0d232e ] uart_handle_dcd_change() requires a port lock to be held and will emit a warning when lockdep is enabled. Held corresponding lock to fix the following warnings. [ 132.528648] WARNING: CPU: 5 PID: 11600 at drivers/tty/serial/serial_core.c:3046 uart_handle_dcd_change+0xf4/0x120 [ 132.530482] Modules linked in: [ 132.531050] CPU: 5 PID: 11600 Comm: jsm Not tainted 5.14.0-rc1-00003-g7fef2edf7cc7-dirty #31 [ 132.535268] RIP: 0010:uart_handle_dcd_change+0xf4/0x120 [ 132.557100] Call Trace: [ 132.557562] ? __free_pages+0x83/0xb0 [ 132.558213] neo_parse_modem+0x156/0x220 [ 132.558897] neo_param+0x399/0x840 [ 132.559495] jsm_tty_open+0x12f/0x2d0 [ 132.560131] uart_startup.part.18+0x153/0x340 [ 132.560888] ? lock_is_held_type+0xe9/0x140 [ 132.561660] uart_port_activate+0x7f/0xe0 [ 132.562351] ? uart_startup.part.18+0x340/0x340 [ 132.563003] tty_port_open+0x8d/0xf0 [ 132.563523] ? uart_set_options+0x1e0/0x1e0 [ 132.564125] uart_open+0x24/0x40 [ 132.564604] tty_open+0x15c/0x630 Signed-off-by: Zheyu Ma <zheyuma97@gmail.com> Link: https://lore.kernel.org/r/1626242003-3809-1-git-send-email-zheyuma97@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-15tty: serial: fsl_lpuart: fix the wrong mapbase valueAndy Duan1-1/+1
[ Upstream commit d5c38948448abc2bb6b36dbf85a554bf4748885e ] Register offset needs to be applied on mapbase also. dma_tx/rx_request use the physical address of UARTDATA. Register offset is currently only applied to membase (the corresponding virtual addr) but not on mapbase. Fixes: 24b1e5f0e83c ("tty: serial: lpuart: add imx7ulp support") Reviewed-by: Leonard Crestez <leonard.crestez@nxp.com> Signed-off-by: Adriana Reus <adriana.reus@nxp.com> Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Signed-off-by: Andy Duan <fugang.duan@nxp.com> Link: https://lore.kernel.org/r/20210819021033.32606-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-12serial: 8250: 8250_omap: Fix unused variable warningVignesh Raghavendra1-13/+13
commit 6f991850412963381017cfb0d691cbd4d6a551dc upstream. With commit 439c7183e5b9 ("serial: 8250: 8250_omap: Disable RX interrupt after DMA enable"), below warning is seen with W=1 and CONFIG_SERIAL_8250_DMA is disabled: drivers/tty/serial/8250/8250_omap.c:1199:42: warning: unused variable 'k3_soc_devices' [-Wunused-const-variable] Fix this by moving the code using k3_soc_devices array to omap_serial_fill_features_erratas() that handles other errata flags as well. Fixes: 439c7183e5b9 ("serial: 8250: 8250_omap: Disable RX interrupt after DMA enable") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com> Link: https://lore.kernel.org/r/20201111112653.2710-2-vigneshr@ti.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-08serial: 8250: 8250_omap: Fix possible array out of bounds accessVignesh Raghavendra1-0/+1
commit d4548b14dd7e5c698f81ce23ce7b69a896373b45 upstream. k3_soc_devices array is missing a sentinel entry which may result in out of bounds access as reported by kernel KASAN. Fix this by adding a sentinel entry. Fixes: 439c7183e5b9 ("serial: 8250: 8250_omap: Disable RX interrupt after DMA enable") Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com> Link: https://lore.kernel.org/r/20201111112653.2710-1-vigneshr@ti.com Signed-off-by: Nobuhiro Iwamatsu (CIP) <nobuhiro1.iwamatsu@toshiba.co.jp> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-12serial: 8250_pci: Avoid irq sharing for MSI(-X) interrupts.Mario Kleiner1-0/+1
commit 341abd693d10e5f337a51f140ae3e7a1ae0febf6 upstream. 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 <ralf.ramsauer@oth-regensburg.de> Cc: stable <stable@vger.kernel.org> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com> Link: https://lore.kernel.org/r/20210729043306.18528-1-mario.kleiner.de@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-12serial: 8250_pci: Enumerate Elkhart Lake UARTs via dedicated driverAndy Shevchenko1-0/+6
commit 7f0909db761535aefafa77031062603a71557267 upstream. 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 <stable@vger.kernel.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20210713101739.36962-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-12serial: 8250: Mask out floating 16/32-bit bus bitsMaciej W. Rozycki1-3/+9
commit e5227c51090e165db4b48dcaa300605bfced7014 upstream. 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: <git://git.kernel.org/pub/scm/linux/kernel/git/ralf/linux.git> 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 <f4bug@amsat.org> Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2106260516220.37803@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-12serial: 8250_mtk: fix uart corruption issue when rx power offZhiyong Tao1-0/+5
commit 7c4a509d3815a260c423c0633bd73695250ac26d upstream. 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 <zhiyong.tao@mediatek.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20210729084640.17613-2-zhiyong.tao@mediatek.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-12serial: tegra: Only print FIFO error message when an error occursJon Hunter1-2/+4
commit cc9ca4d95846cbbece48d9cd385550f8fba6a3c1 upstream. 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: <stable@vger.kernel.org> Acked-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Link: https://lore.kernel.org/r/20210630125643.264264-1-jonathanh@nvidia.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-20serial: tty: uartlite: fix console setupDaniel Mack1-21/+6
[ Upstream commit d157fca711ad42e75efef3444c83d2e1a17be27a ] Remove the hack to assign the global console_port variable at probe time. This assumption that cons->index is -1 is wrong for systems that specify 'console=' in the cmdline (or 'stdout-path' in dts). Hence, on such system the actual console assignment is ignored, and the first UART that happens to be probed is used as console instead. Move the logic to console_setup() and map the console to the correct port through the array of available ports instead. Signed-off-by: Daniel Mack <daniel@zonque.org> Link: https://lore.kernel.org/r/20210528133321.1859346-1-daniel@zonque.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-20tty: serial: 8250: serial_cs: Fix a memory leak in error handling pathChristophe JAILLET1-1/+10
[ Upstream commit fad92b11047a748c996ebd6cfb164a63814eeb2e ] In the probe function, if the final 'serial_config()' fails, 'info' is leaking. Add a resource handling path to free this memory. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Link: https://lore.kernel.org/r/dc25f96b7faebf42e60fe8d02963c941cf4d8124.1621971720.git.christophe.jaillet@wanadoo.fr Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-20serial: fsl_lpuart: disable DMA for console and fix sysrqMichael Walle1-0/+6
[ Upstream commit 8cac2f6eb8548245e6f8fb893fc7f2a714952654 ] SYSRQ doesn't work with DMA. This is because there is no error indication whether a symbol had a framing error or not. Actually, this is not completely correct, there is a bit in the data register which is set in this case, but we'd have to read change the DMA access to 16 bit and we'd need to post process the data, thus make the DMA pointless in the first place. Signed-off-by: Michael Walle <michael@walle.cc> Link: https://lore.kernel.org/r/20210512141255.18277-10-michael@walle.cc Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-20tty: serial: fsl_lpuart: fix the potential risk of division or modulo by zeroSherry Sun1-0/+3
[ Upstream commit fcb10ee27fb91b25b68d7745db9817ecea9f1038 ] We should be very careful about the register values that will be used for division or modulo operations, althrough the possibility that the UARTBAUD register value is zero is very low, but we had better to deal with the "bad data" of hardware in advance to avoid division or modulo by zero leading to undefined kernel behavior. Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20210427021226.27468-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14serial: mvebu-uart: correctly calculate minimal possible baudratePali Rohár1-3/+8
[ Upstream commit deeaf963569a0d9d1b08babb771f61bb501a5704 ] For default (x16) scheme which is currently used by mvebu-uart.c driver, maximal divisor of UART base clock is 1023*16. Therefore there is limit for minimal supported baudrate. This change calculate it correctly and prevents setting invalid divisor 0 into hardware registers. Signed-off-by: Pali Rohár <pali@kernel.org> Fixes: 68a0db1d7da2 ("serial: mvebu-uart: add function to change baudrate") Link: https://lore.kernel.org/r/20210624224909.6350-4-pali@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14serial: mvebu-uart: do not allow changing baudrate when uartclk is not availablePali Rohár1-3/+2
[ Upstream commit ecd6b010d81f97b06b2f64d2d4f50ebf5acddaa9 ] Testing mvuart->clk for non-error is not enough as mvuart->clk may contain valid clk pointer but when clk_prepare_enable(mvuart->clk) failed then port->uartclk is zero. When mvuart->clk is not available then port->uartclk is zero too. Parent clock rate port->uartclk is needed to calculate UART clock divisor and without it is not possible to change baudrate. So fix test condition when it is possible to change baudrate. Signed-off-by: Pali Rohár <pali@kernel.org> Fixes: 68a0db1d7da2 ("serial: mvebu-uart: add function to change baudrate") Link: https://lore.kernel.org/r/20210624224909.6350-3-pali@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14serial: 8250: 8250_omap: Fix possible interrupt storm on K3 SoCsVignesh Raghavendra1-1/+19
[ Upstream commit b67e830d38fa9335d927fe67e812e3ed81b4689c ] On K3 family of SoCs (which includes AM654 SoC), it is observed that RX TIMEOUT is signalled after RX FIFO has been drained, in which case a dummy read of RX FIFO is required to clear RX TIMEOUT condition. Otherwise, this would lead to an interrupt storm. Fix this by introducing UART_RX_TIMEOUT_QUIRK flag and doing a dummy read in IRQ handler when RX TIMEOUT is reported with no data in RX FIFO. Fixes: be70874498f3 ("serial: 8250_omap: Add support for AM654 UART controller") Reported-by: Jan Kiszka <jan.kiszka@siemens.com> Tested-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com> Link: https://lore.kernel.org/r/20210622145704.11168-1-vigneshr@ti.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14serial: 8250: 8250_omap: Disable RX interrupt after DMA enableVignesh Raghavendra1-1/+41
[ Upstream commit 439c7183e5b97952bba1747f5ffc4dea45a6a18b ] UARTs on TI SoCs prior to J7200 don't provide independent control over RX FIFO not empty interrupt (RHR_IT) and RX timeout interrupt. Starting with J7200 SoC, its possible to disable RHR_IT independent of RX timeout interrupt using bit 2 of IER2 register. So disable RHR_IT once RX DMA is started so as to avoid spurious interrupt being raised when data is in the RX FIFO but is yet to be drained by DMA (a known errata in older SoCs). Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com> Link: https://lore.kernel.org/r/20201029051930.7097-1-vigneshr@ti.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14serial: 8250: Actually allow UPF_MAGIC_MULTIPLIER baud ratesMaciej W. Rozycki1-3/+16