linux-dev/drivers/tty/serial/8250, branch master

parisc/serial: Rename 8250_gsc.c to 8250_parisc.c

2022-10-21T06:10:46Z

The file name of this driver is misleading - it handles various serial ports on parisc machines, not just such on the GSC bus. Rename the file to make this clearer. Suggested-by: Mikulas Patocka Signed-off-by: Helge Deller

parisc: Make 8250_gsc driver dependend on CONFIG_PARISC

2022-10-21T06:10:45Z

Although the name of the driver 8250_gsc.c suggests that it handles only serial ports on the GSC bus, it does handle serial ports listed in the parisc machine inventory as well, e.g. the serial ports in a C8000 PCI-only workstation. Change the dependency to CONFIG_PARISC, so that the driver gets included in the kernel even if CONFIG_GSC isn't set. Reported-by: Mikulas Patocka Cc: Signed-off-by: Helge Deller

serial: 8250: Fix restoring termios speed after suspend

2022-09-25T07:29:44Z

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. Since commit 027b57170bf8 ("serial: core: Fix initializing and restoring termios speed") termios speed is available also in struct console. So properly restore also c_ispeed and c_ospeed members after suspend to fix restoring termios speed which is not represented by Bnnn constant. Fixes: 4516d50aabed ("serial: 8250: Use canary to restart console after suspend") Signed-off-by: Pali Rohár Link: https://lore.kernel.org/r/20220924104324.4035-1-pali@kernel.org Signed-off-by: Greg Kroah-Hartman

serial: Deassert Transmit Enable on probe in driver-specific way

2022-09-25T07:28:57Z

When a UART port is newly registered, uart_configure_port() seeks to deassert RS485 Transmit Enable by setting the RTS bit in port->mctrl. However a number of UART drivers interpret a set RTS bit as *assertion* instead of deassertion: Affected drivers include those using serial8250_em485_config() (except 8250_bcm2835aux.c) and some using mctrl_gpio (e.g. imx.c). Since the interpretation of the RTS bit is driver-specific, it is not suitable as a means to centrally deassert Transmit Enable in the serial core. Instead, the serial core must call on drivers to deassert it in their driver-specific way. One way to achieve that is to call ->rs485_config(). It implicitly deasserts Transmit Enable. So amend uart_configure_port() and uart_resume_port() to invoke uart_rs485_config(). That allows removing calls to uart_rs485_config() from drivers' ->probe() hooks and declaring the function static. Skip any invocation of ->set_mctrl() if RS485 is enabled. RS485 has no hardware flow control, so the modem control lines are irrelevant and need not be touched. When leaving RS485 mode, reset the modem control lines to the state stored in port->mctrl. That way, UARTs which are muxed between RS485 and RS232 transceivers drive the lines correctly when switched to RS232. (serial8250_do_startup() historically raises the OUT1 modem signal because otherwise interrupts are not signaled on ancient PC UARTs, but I believe that no longer applies to modern, RS485-capable UARTs and is thus safe to be skipped.) imx.c modifies port->mctrl whenever Transmit Enable is asserted and deasserted. Stop it from doing that so port->mctrl reflects the RS232 line state. 8250_omap.c deasserts Transmit Enable on ->runtime_resume() by calling ->set_mctrl(). Because that is now a no-op in RS485 mode, amend the function to call serial8250_em485_stop_tx(). fsl_lpuart.c retrieves and applies the RS485 device tree properties after registering the UART port. Because applying now happens on registration in uart_configure_port(), move retrieval of the properties ahead of uart_add_one_port(). Link: https://lore.kernel.org/all/20220329085050.311408-1-matthias.schiffer@ew.tq-group.com/ Link: https://lore.kernel.org/all/8f538a8903795f22f9acc94a9a31b03c9c4ccacb.camel@ginzinger.com/ Fixes: d3b3404df318 ("serial: Fix incorrect rs485 polarity on uart open") Cc: stable@vger.kernel.org # v4.14+ Reported-by: Matthias Schiffer Reported-by: Roosen Henri Tested-by: Matthias Schiffer Reviewed-by: Ilpo Järvinen Signed-off-by: Lukas Wunner Link: https://lore.kernel.org/r/2de36eba3fbe11278d5002e4e501afe0ceaca039.1663863805.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman

serial: 8250_dma: Convert to use uart_xmit_advance()

2022-09-25T07:27:41Z

uart_xmit_advance() provides a common way on how to advance the Tx queue. Use it for the sake of unification and robustness. Reviewed-by: Ilpo Järvinen Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20220909091102.58941-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: 8250_omap: Convert to use uart_xmit_advance()

2022-09-25T07:27:38Z

uart_xmit_advance() provides a common way on how to advance the Tx queue. Use it for the sake of unification and robustness. Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20220909091258.68886-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman

Merge 7e2cd21e02b3 ("Merge tag 'tty-6.0-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty") into tty-next

2022-09-25T07:22:13Z

We need the tty fixes and api additions in this branch. Signed-off-by: Greg Kroah-Hartman

serial: 8250: omap: Use serial8250_em485_supported

2022-09-22T14:38:06Z

8250_omap uses em485, fill in rs485_supported accordingly. This makes RS485 work with 8250_omap again, which was broken with the introduction of the RS485 config sanitization. Fixes: be2e2cb1d2819 ("serial: Sanitize rs485_struct") Reviewed-by: Ilpo Järvinen Signed-off-by: Matthias Schiffer Link: https://lore.kernel.org/r/20220916110955.161099-1-matthias.schiffer@ew.tq-group.com Signed-off-by: Greg Kroah-Hartman

serial: 8250: Toggle IER bits on only after irq has been set up

2022-09-22T14:30:14Z

Invoking TIOCVHANGUP on 8250_mid port on Ice Lake-D and then reopening the port triggers these faults during serial8250_do_startup(): DMAR: DRHD: handling fault status reg 3 DMAR: [DMA Write NO_PASID] Request device [00:1a.0] fault addr 0x0 [fault reason 0x05] PTE Write access is not set If the IRQ hasn't been set up yet, the UART will have zeroes in its MSI address/data registers. Disabling the IRQ at the interrupt controller won't stop the UART from performing a DMA write to the address programmed in its MSI address register (zero) when it wants to signal an interrupt. The UARTs (in Ice Lake-D) implement PCI 2.1 style MSI without masking capability, so there is no way to mask the interrupt at the source PCI function level, except disabling the MSI capability entirely, but that would cause it to fall back to INTx# assertion, and the PCI specification prohibits disabling the MSI capability as a way to mask a function's interrupt service request. The MSI address register is zeroed by the hangup as the irq is freed. The interrupt is signalled during serial8250_do_startup() performing a THRE test that temporarily toggles THRI in IER. The THRE test currently occurs before UART's irq (and MSI address) is properly set up. Refactor serial8250_do_startup() such that irq is set up before the THRE test. The current irq setup code is intermixed with the timer setup code. As THRE test must be performed prior to the timer setup, extract it into own function and call it only after the THRE test. The ->setup_timer() needs to be part of the struct uart_8250_ops in order to not create circular dependency between 8250 and 8250_base modules. Fixes: 40b36daad0ac ("[PATCH] 8250 UART backup timer") Reported-by: Lennert Buytenhek Tested-by: Lennert Buytenhek Reviewed-by: Andy Shevchenko Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20220922070005.2965-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: 8250: Request full 16550A feature probing for OxSemi PCIe devices

2022-09-22T14:28:47Z

Oxford Semiconductor PCIe (Tornado) 950 serial port devices need to operate in the enhanced mode via the EFR register for the Divide-by-M N/8 baud rate generator prescaler to be used in their native UART mode. Otherwise the prescaler is fixed at 1 causing grossly incorrect baud rates to be programmed. Accessing the EFR register requires 16550A features to have been probed for, so request this to happen regardless of SERIAL_8250_16550A_VARIANTS by setting UPF_FULL_PROBE in port flags. Fixes: 366f6c955d4d ("serial: 8250: Add proper clock handling for OxSemi PCIe devices") Cc: stable@vger.kernel.org # v5.19+ Reported-by: Anders Blomdell Signed-off-by: Maciej W. Rozycki Link: https://lore.kernel.org/r/alpine.DEB.2.21.2209210005040.41633@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman