user/sven/linux.git/drivers/tty, branch v6.7.9

serial: amba-pl011: Fix DMA transmission in RS485 mode

2024-03-01T12:41:49Z

commit 3b69e32e151bc4a4e3c785cbdb1f918d5ee337ed upstream. When DMA is used in RS485 mode make sure that the UARTs tx section is enabled before the DMA buffers are queued for transmission. Cc: stable@vger.kernel.org Fixes: 8d479237727c ("serial: amba-pl011: add RS485 support") Signed-off-by: Lino Sanfilippo Link: https://lore.kernel.org/r/20240216224709.9928-2-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman

serial: stm32: do not always set SER_RS485_RX_DURING_TX if RS485 is enabled

2024-03-01T12:41:49Z

commit f418ae73311deb901c0110b08d1bbafc20c1820e upstream. Before commit 07c30ea5861f ("serial: Do not hold the port lock when setting rx-during-tx GPIO") the SER_RS485_RX_DURING_TX flag was only set if the rx-during-tx mode was not controlled by a GPIO. Now the flag is set unconditionally when RS485 is enabled. This results in an incorrect setting if the rx-during-tx GPIO is not asserted. Fix this by setting the flag only if the rx-during-tx mode is not controlled by a GPIO and thus restore the correct behaviour. Cc: stable@vger.kernel.org # 6.6+ Fixes: 07c30ea5861f ("serial: Do not hold the port lock when setting rx-during-tx GPIO") Signed-off-by: Lino Sanfilippo Link: https://lore.kernel.org/r/20240216224709.9928-1-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman

serial: mxs-auart: fix tx

2024-02-23T08:51:49Z

commit 7be50f2e8f20fc2299069b28dea59a28e3abe20a upstream. Emil reports: After updating Linux on an i.MX28 board, serial communication over AUART broke. When I TX from the board and measure on the TX pin, it seems like the HW fifo is not emptied before the transmission is stopped. MXS performs weird things with stop_tx(). The driver makes it conditional on uart_tx_stopped(). So the driver needs special handling. Pass the brand new UART_TX_NOSTOP to uart_port_tx_flags() and handle the stop on its own. Signed-off-by: "Jiri Slaby (SUSE)" Reported-by: Emil Kronborg Cc: stable Fixes: 2d141e683e9a ("tty: serial: use uart_port_tx() helper") Closes: https://lore.kernel.org/all/miwgbnvy3hjpnricubg76ytpn7xoceehwahupy25bubbduu23s@om2lptpa26xw/ Tested-by: Stefan Wahren Tested-by: Emil Kronborg Link: https://lore.kernel.org/r/20240201105557.28043-2-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

serial: max310x: prevent infinite while() loop in port startup

2024-02-23T08:51:48Z

commit b35f8dbbce818b02c730dc85133dc7754266e084 upstream. If there is a problem after resetting a port, the do/while() loop that checks the default value of DIVLSB register may run forever and spam the I2C bus. Add a delay before each read of DIVLSB, and a maximum number of tries to prevent that situation from happening. Also fail probe if port reset is unsuccessful. Fixes: 10d8b34a4217 ("serial: max310x: Driver rework") Cc: stable@vger.kernel.org Signed-off-by: Hugo Villeneuve Link: https://lore.kernel.org/r/20240116213001.3691629-5-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman

serial: max310x: fail probe if clock crystal is unstable

2024-02-23T08:51:48Z

commit 8afa6c6decea37e7cb473d2c60473f37f46cea35 upstream. A stable clock is really required in order to use this UART, so log an error message and bail out if the chip reports that the clock is not stable. Fixes: 4cf9a888fd3c ("serial: max310x: Check the clock readiness") Cc: stable@vger.kernel.org Suggested-by: Jan Kundrát Link: https://www.spinics.net/lists/linux-serial/msg35773.html Signed-off-by: Hugo Villeneuve Link: https://lore.kernel.org/r/20240116213001.3691629-4-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman

serial: max310x: improve crystal stable clock detection

2024-02-23T08:51:48Z

commit 93cd256ab224c2519e7c4e5f58bb4f1ac2bf0965 upstream. Some people are seeing a warning similar to this when using a crystal: max310x 11-006c: clock is not stable yet The datasheet doesn't mention the maximum time to wait for the clock to be stable when using a crystal, and it seems that the 10ms delay in the driver is not always sufficient. Jan Kundrát reported that it took three tries (each separated by 10ms) to get a stable clock. Modify behavior to check stable clock ready bit multiple times (20), and waiting 10ms between each try. Note: the first draft of the driver originally used a 50ms delay, without checking the clock stable bit. Then a loop with 1000 retries was implemented, each time reading the clock stable bit. Fixes: 4cf9a888fd3c ("serial: max310x: Check the clock readiness") Cc: stable@vger.kernel.org Suggested-by: Jan Kundrát Link: https://www.spinics.net/lists/linux-serial/msg35773.html Link: https://lore.kernel.org/all/20240110174015.6f20195fde08e5c9e64e5675@hugovil.com/raw Link: https://github.com/boundarydevices/linux/commit/e5dfe3e4a751392515d78051973190301a37ca9a Signed-off-by: Hugo Villeneuve Link: https://lore.kernel.org/r/20240116213001.3691629-3-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman

serial: max310x: set default value when reading clock ready bit

2024-02-23T08:51:48Z

commit 0419373333c2f2024966d36261fd82a453281e80 upstream. If regmap_read() returns a non-zero value, the 'val' variable can be left uninitialized. Clear it before calling regmap_read() to make sure we properly detect the clock ready bit. Fixes: 4cf9a888fd3c ("serial: max310x: Check the clock readiness") Cc: stable@vger.kernel.org Signed-off-by: Hugo Villeneuve Link: https://lore.kernel.org/r/20240116213001.3691629-2-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman

serial: core: Fix atomicity violation in uart_tiocmget

2024-02-23T08:51:47Z

commit 30926783a46841c2d1bbf3f74067ba85d304fd0d upstream. In uart_tiocmget(): result = uport->mctrl; uart_port_lock_irq(uport); result |= uport->ops->get_mctrl(uport); uart_port_unlock_irq(uport); ... return result; In uart_update_mctrl(): uart_port_lock_irqsave(port, &flags); ... port->mctrl = (old & ~clear) | set; ... port->ops->set_mctrl(port, port->mctrl); ... uart_port_unlock_irqrestore(port, flags); An atomicity violation is identified due to the concurrent execution of uart_tiocmget() and uart_update_mctrl(). After assigning result = uport->mctrl, the mctrl value may change in uart_update_mctrl(), leading to a mismatch between the value returned by uport->ops->get_mctrl(uport) and the mctrl value previously read. This can result in uart_tiocmget() returning an incorrect value. This possible bug is found by an experimental static analysis tool developed by our team, BassCheck[1]. This tool analyzes the locking APIs to extract function pairs that can be concurrently executed, and then analyzes the instructions in the paired functions to identify possible concurrency bugs including data races and atomicity violations. The above possible bug is reported when our tool analyzes the source code of Linux 5.17. To address this issue, it is suggested to move the line result = uport->mctrl inside the uart_port_lock block to ensure atomicity and prevent the mctrl value from being altered during the execution of uart_tiocmget(). With this patch applied, our tool no longer reports the bug, with the kernel configuration allyesconfig for x86_64. Due to the absence of the requisite hardware, we are unable to conduct runtime testing of the patch. Therefore, our verification is solely based on code logic analysis. [1] https://sites.google.com/view/basscheck/ Fixes: c5f4644e6c8b ("[PATCH] Serial: Adjust serial locking") Cc: stable@vger.kernel.org Signed-off-by: Gui-Dong Han <2045gemini@gmail.com> Link: https://lore.kernel.org/r/20240112113624.17048-1-2045gemini@gmail.com Signed-off-by: Greg Kroah-Hartman

tty: serial: 8250: Set RS422 interface by default to fix Moxa RS422/RS485 PCIe boards

2024-02-05T20:17:04Z

[ Upstream commit 43f012df3c1e979966524f79b5371fde6545488a ] MOXA PCIe RS422/RS485 boards will not function by default because of the initial default serial interface of all MOXA PCIe boards is set to RS232. This patch fixes the problem above by setting the initial default serial interface to RS422 for those MOXA RS422/RS485 PCIe boards. Signed-off-by: Crescent CY Hsieh Reviewed-by: Jiri Slaby Link: https://lore.kernel.org/r/20231214060234.6147-1-crescentcy.hsieh@moxa.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

tty: allow TIOCSLCKTRMIOS with CAP_CHECKPOINT_RESTORE

2024-02-05T20:17:04Z

[ Upstream commit e0f25b8992345aa5f113da2815f5add98738c611 ] The capability CAP_CHECKPOINT_RESTORE was introduced to allow non-root users to checkpoint and restore processes as non-root with CRIU. This change extends CAP_CHECKPOINT_RESTORE to enable the CRIU option '--shell-job' as non-root. CRIU's man-page describes the '--shell-job' option like this: Allow one to dump shell jobs. This implies the restored task will inherit session and process group ID from the criu itself. This option also allows to migrate a single external tty connection, to migrate applications like top. TIOCSLCKTRMIOS can only be done if the process has CAP_SYS_ADMIN and this change extends it to CAP_SYS_ADMIN or CAP_CHECKPOINT_RESTORE. With this change it is possible to checkpoint and restore processes which have a tty connection as non-root if CAP_CHECKPOINT_RESTORE is set. Acked-by: Christian Brauner Signed-off-by: Adrian Reber Acked-by: Andrei Vagin Link: https://lore.kernel.org/r/20231208143656.1019-1-areber@redhat.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin