linux/drivers/tty/serial, branch v5.17

Merge tag 'tty-5.17-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2022-02-25T19:45:29Z

Pull tty/serial driver fixes from Greg KH: "Here are some small n_gsm and sc16is7xx serial driver fixes for 5.17-rc6. The n_gsm fixes are from Siemens as it seems they are using the line discipline and fixing up a number of issues they found in their testing. The sc16is7xx serial driver fix is for a reported problem with that chip. All of these have been in linux-next with no reported problems" * tag 'tty-5.17-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: sc16is7xx: Fix for incorrect data being transmitted tty: n_gsm: fix deadlock in gsmtty_open() tty: n_gsm: fix wrong modem processing in convergence layer type 2 tty: n_gsm: fix wrong tty control line for flow control tty: n_gsm: fix NULL pointer access due to DLCI release tty: n_gsm: fix proper link termination after failed open tty: n_gsm: fix encoding of command/response bit tty: n_gsm: fix encoding of control signal octet bit DV

sc16is7xx: Fix for incorrect data being transmitted

2022-02-21T18:51:39Z

UART drivers are meant to use the port spinlock within certain methods, to protect against reentrancy. The sc16is7xx driver does very little locking, presumably because when added it triggers "scheduling while atomic" errors. This is due to the use of mutexes within the regmap abstraction layer, and the mutex implementation's habit of sleeping the current thread while waiting for access. Unfortunately this lack of interlocking can lead to corruption of outbound data, which occurs when the buffer used for I2C transmission is used simultaneously by two threads - a work queue thread running sc16is7xx_tx_proc, and an IRQ thread in sc16is7xx_port_irq, both of which can call sc16is7xx_handle_tx. An earlier patch added efr_lock, a mutex that controls access to the EFR register. This mutex is already claimed in the IRQ handler, and all that is required is to claim the same mutex in sc16is7xx_tx_proc. See: https://github.com/raspberrypi/linux/issues/4885 Fixes: 6393ff1c4435 ("sc16is7xx: Use threaded IRQ") Cc: stable Signed-off-by: Phil Elwell Link: https://lore.kernel.org/r/20220216160802.1026013-1-phil@raspberrypi.com Signed-off-by: Greg Kroah-Hartman

Merge tag 'for-5.17/parisc-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux

2022-02-15T17:10:09Z

Pull parisc architecture fixes from Helge Deller: - Fix miscompilations when function calls are made from inside a put_user() call - Drop __init from map_pages() declaration to avoid random boot crashes - Added #error messages if a 64-bit compiler was used to build a 32-bit kernel (and vice versa) - Fix out-of-bound data TLB miss faults in sba_iommu and ccio-dma drivers - Add ioread64_lo_hi() and iowrite64_lo_hi() functions to avoid kernel test robot errors - Fix link failure when 8250_gsc driver is built without CONFIG_IOSAPIC * tag 'for-5.17/parisc-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: serial: parisc: GSC: fix build when IOSAPIC is not set parisc: Fix some apparent put_user() failures parisc: Show error if wrong 32/64-bit compiler is being used parisc: Add ioread64_lo_hi() and iowrite64_lo_hi() parisc: Fix sglist access in ccio-dma.c parisc: Fix data TLB miss in sba_unmap_sg parisc: Drop __init from map_pages declaration

serial: parisc: GSC: fix build when IOSAPIC is not set

2022-02-14T18:34:42Z

There is a build error when using a kernel .config file from 'kernel test robot' for a different build problem: hppa64-linux-ld: drivers/tty/serial/8250/8250_gsc.o: in function `.LC3': (.data.rel.ro+0x18): undefined reference to `iosapic_serial_irq' when: CONFIG_GSC=y CONFIG_SERIO_GSCPS2=y CONFIG_SERIAL_8250_GSC=y CONFIG_PCI is not set and hence PCI_LBA is not set. IOSAPIC depends on PCI_LBA, so IOSAPIC is not set/enabled. Make the use of iosapic_serial_irq() conditional to fix the build error. Signed-off-by: Randy Dunlap Reported-by: kernel test robot Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: linux-parisc@vger.kernel.org Cc: Greg Kroah-Hartman Cc: linux-serial@vger.kernel.org Cc: Jiri Slaby Cc: Johan Hovold Suggested-by: Helge Deller Signed-off-by: Helge Deller Cc: stable@vger.kernel.org Signed-off-by: Helge Deller

serial: 8250_pericom: Revert "Re-enable higher baud rates"

2022-02-04T14:32:05Z

UPF_MAGIC_MULTIPLIER is userspace available bit and can be changed at any time. There is no sense to rely on it to be always present. This reverts commit b4ccaf5aa2d795ee7f47a6eeb209f3de981e1929. Note, that code was not reliably worked before, hence it implies no functional change. Signed-off-by: Andy Shevchenko Fixes: b4ccaf5aa2d7 ("serial: 8250_pericom: Re-enable higher baud rates") Link: https://lore.kernel.org/r/20220203150026.19087-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: core: Initialize rs485 RTS polarity already on probe

2022-01-26T13:53:12Z

RTS polarity of rs485-enabled ports is currently initialized on uart open via: tty_port_open() tty_port_block_til_ready() tty_port_raise_dtr_rts() # if (C_BAUD(tty)) uart_dtr_rts() uart_port_dtr_rts() There's at least three problems here: First, if no baud rate is set, RTS polarity is not initialized. That's the right thing to do for rs232, but not for rs485, which requires that RTS is deasserted unconditionally. Second, if the DeviceTree property "linux,rs485-enabled-at-boot-time" is present, RTS should be deasserted as early as possible, i.e. on probe. Otherwise it may remain asserted until first open. Third, even though RTS is deasserted on open and close, it may subsequently be asserted by uart_throttle(), uart_unthrottle() or uart_set_termios() because those functions aren't rs485-aware. (Only uart_tiocmset() is.) To address these issues, move RTS initialization from uart_port_dtr_rts() to uart_configure_port(). Prevent subsequent modification of RTS polarity by moving the existing rs485 check from uart_tiocmget() to uart_update_mctrl(). That way, RTS is initialized on probe and then remains unmodified unless the uart transmits data. If rs485 is enabled at runtime (instead of at boot) through a TIOCSRS485 ioctl(), RTS is initialized by the uart driver's ->rs485_config() callback and then likewise remains unmodified. The PL011 driver initializes RTS on uart open and prevents subsequent modification in its ->set_mctrl() callback. That code is obsoleted by the present commit, so drop it. Cc: Jan Kiszka Cc: Su Bao Cheng Signed-off-by: Lukas Wunner Link: https://lore.kernel.org/r/2d2acaf3a69e89b7bf687c912022b11fd29dfa1e.1642909284.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman

serial: pl011: Fix incorrect rs485 RTS polarity on set_mctrl

2022-01-26T13:53:12Z

Commit 8d479237727c ("serial: amba-pl011: add RS485 support") sought to keep RTS deasserted on set_mctrl if rs485 is enabled. However it did so only if deasserted RTS polarity is high. Fix it in case it's low. Fixes: 8d479237727c ("serial: amba-pl011: add RS485 support") Cc: stable@vger.kernel.org # v5.15+ Cc: Lino Sanfilippo Signed-off-by: Jochen Mades [lukas: copyedit commit message, add stable designation] Signed-off-by: Lukas Wunner Link: https://lore.kernel.org/r/85fa3323ba8c307943969b7343e23f34c3e652ba.1642909284.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman

serial: stm32: fix software flow control transfer

2022-01-26T13:52:49Z

x_char is ignored by stm32_usart_start_tx() when xmit buffer is empty. Fix start_tx condition to allow x_char to be sent. Fixes: 48a6092fb41f ("serial: stm32-usart: Add STM32 USART Driver") Cc: stable Signed-off-by: Erwan Le Ray Signed-off-by: Valentin Caron Link: https://lore.kernel.org/r/20220111164441.6178-3-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman

serial: stm32: prevent TDR register overwrite when sending x_char

2022-01-26T13:52:44Z

When sending x_char in stm32_usart_transmit_chars(), driver can overwrite the value of TDR register by the value of x_char. If this happens, the previous value that was present in TDR register will not be sent through uart. This code checks if the previous value in TDR register is sent before writing the x_char value into register. Fixes: 48a6092fb41f ("serial: stm32-usart: Add STM32 USART Driver") Cc: stable Signed-off-by: Valentin Caron Link: https://lore.kernel.org/r/20220111164441.6178-2-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman

serial: 8250: of: Fix mapped region size when using reg-offset property

2022-01-26T13:50:52Z

8250_of supports a reg-offset property which is intended to handle cases where the device registers start at an offset inside the region of memory allocated to the device. The Xilinx 16550 UART, for which this support was initially added, requires this. However, the code did not adjust the overall size of the mapped region accordingly, causing the driver to request an area of memory past the end of the device's allocation. For example, if the UART was allocated an address of 0xb0130000, size of 0x10000 and reg-offset of 0x1000 in the device tree, the region of memory reserved was b0131000-b0140fff, which caused the driver for the region starting at b0140000 to fail to probe. Fix this by subtracting reg-offset from the mapped region size. Fixes: b912b5e2cfb3 ([POWERPC] Xilinx: of_serial support for Xilinx uart 16550.) Cc: stable Signed-off-by: Robert Hancock Link: https://lore.kernel.org/r/20220112194214.881844-1-robert.hancock@calian.com Signed-off-by: Greg Kroah-Hartman