summaryrefslogtreecommitdiffstats
path: root/drivers/tty
Commit message (Collapse)AuthorAgeFilesLines
...
| * | | tty: n_gsm: do not send/receive in ldisc close pathSascha Hauer2017-06-031-19/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | gsm_cleanup_mux() is called in the line discipline close path which is called at tty_release() time. At this stage the tty is no longer operational enough to send any frames. Sending close frames is therefore not possible and waiting for their answers always times out. This patch removes sending close messages and waiting for their answers from the tty_release path. This patch makes explicit what previously implicitly had been the case already: We are not able to tell the modem that we are about to close the multiplexer on our side. This means the modem will stay in multiplexer mode and re-establishing the multiplexer later fails. The only way for userspace to work around this is to manually send a close frame in N_TTY mode after closing the mux. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | Fix serial console on SNI RM400 machinesThomas Bogendoerfer2017-06-031-5/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sccnxp driver doesn't get the correct uart clock rate, if CONFIG_HAVE_CLOCK is disabled. Correct usage of clk API to make it work with/without it. Fixes: 90efa75f7ab0 (serial: sccnxp: Using CLK API for getting UART clock) Suggested-by: Russell King - ARM Linux <linux@armlinux.org.uk> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | tty: handle the case where we cannot restore a line disciplineAlan Cox2017-06-033-15/+112
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Historically the N_TTY driver could never fail but this has become broken over time. Rather than trying to rewrite half the ldisc layer to fix the breakage introduce a second level of fallback with an N_NULL ldisc which cannot fail, and thus restore the guarantees required by the ldisc layer. We still try and fail to N_TTY first. It's much more useful to find yourself back in your old ldisc (first attempt) or in N_TTY (second attempt), and while I'm not aware of any code out there that makes those assumptions it's good to drive(r) defensively. Signed-off-by: Alan Cox <alan@linux.intel.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | Merge 4.12-rc3 into tty-nextGreg Kroah-Hartman2017-05-2911-40/+141
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | We need the tty fixes/changes here to handle future work. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: 8250: Add CAP_MINI, set for bcm2835auxPhil Elwell2017-05-243-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The AUX/mini-UART in the BCM2835 family of procesors is a cut-down 8250 clone. In particular it is lacking support for the following features: CSTOPB PARENB PARODD CMSPAR CS5 CS6 Add a new capability (UART_CAP_MINI) that exposes the restrictions to the user of the termios API by turning off the unsupported features in the request. N.B. It is almost possible to automatically discover the missing features by reading back the LCR register, but the CSIZE bits don't cooperate (contrary to the documentation, both bits are significant, but CS5 and CS6 are mapped to CS7) and the code is much longer. See: https://github.com/raspberrypi/linux/issues/1561 Signed-off-by: Phil Elwell <phil@raspberrypi.org> Acked-by: Eric Anholt <eric@anholt.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: sh-sci: Update warning message in sci_request_dma_chan()Geert Uytterhoeven2017-05-241-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The commit below changed a function call from dma_request_slave_channel_compat() to dma_request_slave_channel(), but forgot to update the printed failure message. Fixes: 219fb0c1436e4893 ("serial: sh-sci: Remove the platform data dma slave rx/tx channel IDs") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: meson: hide an unused functionArnd Bergmann2017-05-241-9/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The newly added meson_uart_enable_tx_engine function is only called from the console setup, not the runtime uart, which has an open-coded version of the same register access. This produces a harmless warning when the console code is disabled: drivers/tty/serial/meson_uart.c:127:13: error: 'meson_uart_enable_tx_engine' defined but not used [-Werror=unused-function] Let's move the function inside of the #ifdef to avoid the warning. Fixes: ba50f1df13c8 ("serial: meson: remove unneeded variable assignment in meson_serial_port_write") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: xilinx_uartps: Fix the error pathShubhrajyoti Datta2017-05-181-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix the runtime calls in the error path. Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: meson: change interrupt description to tty nameHeiner Kallweit2017-05-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change interrupt description from driver name to tty name (e.g. ttyAML0). If multiple serial ports are enabled this allows to determine which interrupt belongs to which port in /proc/interrupts. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: meson: remove use of flag UPF_IOREMAPHeiner Kallweit2017-05-181-14/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Flag UPF_IOREMAP is used by the 8250 subsystem only, it's not used by the serial core. Therefore I don't see any benefit in using it here. In addition fix the order of calls in meson_uart_release_port. Unmapping needs to be done first, reversing call order in meson_uart_request_port. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: meson: make use of uart_port member mapsizeHeiner Kallweit2017-05-181-24/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Member mapsize of struct uart_port is meant to store the resource size. By using it we can get rid of meson_uart_res_size(). Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: meson: remove dead code in meson_uart_change_speedHeiner Kallweit2017-05-181-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | val is set in both branches of the if clause, therefore the two removed lines are dead code. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: meson: remove unneeded variable assignment in meson_serial_port_writeHeiner Kallweit2017-05-181-1/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's no need to set AML_UART_TX_EN in each call to meson_serial_port_write. In addition to meson_uart_startup set this flag in meson_serial_console_setup and meson_serial_early_console_setup. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: meson: fix setting number of stop bitsHeiner Kallweit2017-05-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The stop bit value as to be or'ed, so far this worked only just by chance because AML_UART_STOP_BIN_1SB is 0. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | tty/vt/keyboard: Remove AVR32 bits from the driverAndy Shevchenko2017-05-181-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | AVR32 is gone. Now it's time to clean up the driver by removing leftovers that was used by AVR32 related code. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: pch_uart: use offset_in_page() macroGeliang Tang2017-05-181-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use offset_in_page() macro instead of open-coding. Signed-off-by: Geliang Tang <geliangtang@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | tty/serial: atmel: use offset_in_page() macroGeliang Tang2017-05-181-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use offset_in_page() macro instead of open-coding. Signed-off-by: Geliang Tang <geliangtang@gmail.com> Acked-by: Richard Genoud <richard.genoud@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | drivers/tty/hvc: fix spelling mistake: "missmanaged" -> "mismanaged"Colin Ian King2017-05-181-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Trivial fix to spelling mistake in printk message Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: exar: Preconfigure xr17v35x MPIOs as outputJan Kiszka2017-05-181-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is the safe default for GPIOs with unknown external wiring. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | imx-serial: RX DMA startup latencyPeter Senna Tschudin2017-05-181-21/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 18a4208 introduced a change to reduce the RX DMA latency on the first reception when the serial port was opened for reading. However it was claiming a hardirq unsafe lock after a hardirq safe lock which is not allowed and causes lockdep to complain verbosely. This patch changes the code to always start RX DMA earlier, instead of relying on the flags used to open the serial port removing the code that was looking for the serial file flags. Signed-off-by: Peter Senna Tschudin <peter.senna@collabora.com> Tested-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | tty: serdev-ttyport: return actual baudrate from ttyport_set_baudrateStefan Wahren2017-05-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of returning the requested baudrate, we better return the actual one because it isn't always the same. Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: sh-sci: Move uart_register_driver call to device probeSjoerd Simons2017-05-181-11/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | uart_register_driver call binds the driver to a specific device node through tty_register_driver call. This should typically happen during device probe call. In a multiplatform scenario, it is possible that multiple serial drivers are part of the kernel. Currently the driver registration fails if multiple serial drivers with overlapping major/minor numbers are included. Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: pl010: Move uart_register_driver call to device probeSjoerd Simons2017-05-181-10/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | uart_register_driver call binds the driver to a specific device node through tty_register_driver call. This should typically happen during device probe call. In a multiplatform scenario, it is possible that multiple serial drivers are part of the kernel. Currently the driver registration fails if multiple serial drivers with overlapping major/minor numbers are included. Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: sh-sci: Fix race condition causing garbage during shutdownGeert Uytterhoeven2017-05-181-2/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If DMA is enabled and used, a burst of old data may be seen on the serial console during "poweroff" or "reboot". uart_flush_buffer() clears the circular buffer, but sci_port.tx_dma_len is not reset. This leads to a circular buffer overflow, dumping (UART_XMIT_SIZE - sci_port.tx_dma_len) bytes. To fix this, add a .flush_buffer() callback that resets sci_port.tx_dma_len. Inspired by commit 31ca2c63fdc0aee7 ("tty/serial: atmel: fix race condition (TX+DMA)"). Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | drivers/serial: Add driver for Aspeed virtual UARTJeremy Kerr2017-05-183-0/+334
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This change adds a driver for the 16550-based Aspeed virtual UART device. We use a similar process to the of_serial driver for device probe, but expose some VUART-specific functions through sysfs too. The VUART is two UART 'front ends' connected by their FIFO (no actual serial line in between). One is on the BMC side (management controller) and one is on the host CPU side. This driver is for the BMC side. The sysfs files allow the BMC userspace, which owns the system configuration policy, to specify at what IO port and interrupt number the host side will appear to the host on the Host <-> BMC LPC bus. It could be different on a different system (though most of them use 3f8/4). OpenPOWER host firmware doesn't like it when the host-side of the VUART's FIFO is not drained. This driver only disables host TX discard mode when the port is in use. We set the VUART enabled bit when we bind to the device, and clear it on unbind. We don't want to do this on open/release, as the host may be using this bit to configure serial output modes, which is independent of whether the devices has been opened by BMC userspace. Signed-off-by: Jeremy Kerr <jk@ozlabs.org> Signed-off-by: Joel Stanley <joel@jms.id.au> Acked-by: Rob Herring <robh@kernel.org> Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: 8250: Add flag so drivers can avoid THRE probeJoel Stanley2017-05-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The probing of THRE irq behaviour assumes the other end will be reading bytes out of the buffer in order to probe the port at driver init. In some cases the other end cannot be relied upon to read these bytes, so provide a flag for them to skip this step. Bit 19 was chosen as the flags are a int and the top bits are taken. Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: 8250_exar: Remove duplicate assignmentAndy Shevchenko2017-05-181-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | UPF_EXAR_EFR is set globally for each port enumerated by the driver. Thus, no need to repeat this in individual ->setup() hook. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: 8250: omap: Disable DMA for console UARTVignesh R2017-05-181-0/+4
| | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Kernel always writes log messages to console via serial8250_console_write()->serial8250_console_putchar() which directly accesses UART_TX register _without_ using DMA. But, if other processes like systemd using same UART port, then these writes are handled by a different code flow using 8250_omap driver where there is provision to use DMA. It seems that it is possible that both DMA and CPU might simultaneously put data to UART FIFO and lead to potential loss of data due to FIFO overflow and weird data corruption. This happens when both kernel console and userspace tries to write simultaneously to the same UART port. Therefore, disable DMA on kernel console port to avoid potential race between CPU and DMA. Signed-off-by: Vignesh R <vigneshr@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | | Merge tag 'staging-4.13-rc1' of ↵Linus Torvalds2017-07-032-3/+59
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging Pull staging/IIO updates from Greg KH: "Here's the large set of staging and iio driver patches for 4.13-rc1. After over 500 patches, we removed about 200 more lines of code than we added, not great, but we added some new IIO drivers for unsupported hardware, so it's an overall win. Also here are lots of small fixes, and some tty core api additions (with the tty maintainer's ack) for the speakup drivers, those are finally getting some much needed cleanups and are looking much better now than before. Full details in the shortlog. All of these have been in linux-next for a while with no reported issues" * tag 'staging-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (529 commits) staging: lustre: replace kmalloc with kmalloc_array Staging: ion: fix code style warning from NULL comparisons staging: fsl-mc: make dprc.h header private staging: fsl-mc: move mc-cmd.h contents in the public header staging: fsl-mc: move mc-sys.h contents in the public header staging: fsl-mc: fix a few implicit includes staging: fsl-mc: remove dpmng API files staging: fsl-mc: move rest of mc-bus.h to private header staging: fsl-mc: move couple of definitions to public header staging: fsl-mc: move irq domain creation prototype to public header staging: fsl-mc: turn several exported functions static staging: fsl-mc: delete prototype of unimplemented function staging: fsl-mc: delete duplicated function prototypes staging: fsl-mc: decouple the mc-bus public headers from dprc.h staging: fsl-mc: drop useless #includes staging: fsl-mc: be consistent when checking strcmp() return staging: fsl-mc: move comparison before strcmp() call staging: speakup: make function ser_to_dev static staging: ks7010: fix spelling mistake: "errror" -> "error" staging: rtl8192e: fix spelling mistake: "respose" -> "response" ...
| * | | | tty: add function to convert device name to numberOkash Khawaja2017-06-271-0/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function converts strings like ttyS0 and ttyUSB0 to dev_t like (4, 64) and (188, 0). It does this by scanning tty_drivers list for corresponding device name and index. If the driver is not registered, this function returns -ENODEV. It also acquires tty_mutex. Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | Merge 4.12-rc5 into staging-nextGreg Kroah-Hartman2017-06-1211-40/+139
| |\ \ \ \ | | | |_|/ | | |/| | | | | | | | | | | | | | | | | We want the IIO fixes and other staging driver fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | staging: speakup: add tty-based comms functionsOkash Khawaja2017-05-161-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds spk_ttyio.c file. It contains a set of functions which implement those methods in spk_synth struct which relate to sending bytes out using serial comms. Implementations in this file perform the same function but using TTY subsystem instead. Currently synths access serial ports, directly poking standard ISA ports by trying to steal them from serial driver. Some ISA cards actually need this way of doing it, but most other synthesizers don't, and can actually work by using the proper TTY subsystem through a new N_SPEAKUP line discipline. So this adds the methods for drivers to switch to accessing serial ports through the TTY subsystem, whenever appropriate. Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com> Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | tty: export tty_open_by_driverOkash Khawaja2017-05-161-3/+7
| | |/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This exports tty_open_by_driver so that it can be called from other places inside the kernel. The checks for null file pointer are based on Alan Cox's patch here: http://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1215095.html. Description below is quoted from it: "[RFC] tty_port: allow a port to be opened with a tty that has no file handle Let us create tty objects entirely in kernel space. Untested proposal to show why all the ideas around rewriting half the uart stack are not needed. With this a kernel created non file backed tty object could be used to handle data, and set terminal modes. Not all ldiscs can cope with this as N_TTY in particular has to work back to the fs/tty layer. The tty_port code is however otherwise clean of file handles as far as I can tell as is the low level tty port write path used by the ldisc, the configuration low level interfaces and most of the ldiscs. Currently you don't have any exposure to see tty hangups because those are built around the file layer. However a) it's a fixed port so you probably don't care about that b) if you do we can add a callback and c) you almost certainly don't want the userspace tear down/rebuild behaviour anyway. This should however be sufficient if we wanted for example to enumerate all the bluetooth bound fixed ports via ACPI and make them directly available. It doesn't deal with the case of a user opening a port that's also kernel opened and that would need some locking out (so it returned EBUSY if bound to a kernel device of some kind). That needs resolving along with how you "up" or "down" your new bluetooth device, or enumerate it while providing the existing tty API to avoid regressions (and to debug)." The exported funtion is used later in this patch set to gain access to tty_struct. [changed export symbol level - gkh] Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com> Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | | Merge branch 'for-linus' of ↵Linus Torvalds2017-07-031-1/+1
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Martin Schwidefsky: "The bulk of the s390 patches for 4.13. Some new things but mostly bug fixes and cleanups. Noteworthy changes: - The SCM block driver is converted to blk-mq - Switch s390 to 5 level page tables. The virtual address space for a user space process can now have up to 16EB-4KB. - Introduce a ELF phdr flag for qemu to avoid the global vm.alloc_pgste which forces all processes to large page tables - A couple of PCI improvements to improve error recovery - Included is the merge of the base support for proper machine checks for KVM" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (52 commits) s390/dasd: Fix faulty ENODEV for RO sysfs attribute s390/pci: recognize name clashes with uids s390/pci: provide more debug information s390/pci: fix handling of PEC 306 s390/pci: improve pci hotplug s390/pci: introduce clp_get_state s390/pci: improve error handling during fmb (de)registration s390/pci: improve unreg_ioat error handling s390/pci: improve error handling during interrupt deregistration s390/pci: don't cleanup in arch_setup_msi_irqs KVM: s390: Backup the guest's machine check info s390/nmi: s390: New low level handling for machine check happening in guest s390/fpu: export save_fpu_regs for all configs s390/kvm: avoid global config of vm.alloc_pgste=1 s390: rename struct psw_bits members s390: rename psw_bits enums s390/mm: use correct address space when enabling DAT s390/cio: introduce io_subchannel_type s390/ipl: revert Load Normal semantics for LPAR CCW-type re-IPL s390/dumpstack: remove raw stack dump ...
| * | | | s390/hvc_iucv: fix broken Kconfig select statementHeiko Carstens2017-06-121-1/+1
| |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Select statements in Kconfig do not necessarily enable all required dependencies and can lead to broken configs. This is also the case for the "select IUCV" statement within HVC_IUCV: warning: (HVC_IUCV) selects IUCV which has unmet direct dependencies (NET && S390) Just add the missing "depends on NET" to avoid broken configs. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | | | sched/wait: Rename wait_queue_t => wait_queue_entry_tIngo Molnar2017-06-201-1/+1
| |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rename: wait_queue_t => wait_queue_entry_t 'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue", but in reality it's a queue *entry*. The 'real' queue is the wait queue head, which had to carry the name. Start sorting this out by renaming it to 'wait_queue_entry_t'. This also allows the real structure name 'struct __wait_queue' to lose its double underscore and become 'struct wait_queue_entry', which is the more canonical nomenclature for such data types. Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | Revert "tty: fix port buffer locking"Greg Kroah-Hartman2017-06-041-2/+0
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 925bb1ce47f429f69aad35876df7ecd8c53deb7e. It causes lots of warnings and problems so for now, let's just revert it. Reported-by: <valdis.kletnieks@vt.edu> Reported-by: Russell King <linux@armlinux.org.uk> Reported-by: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Reported-by: Jiri Slaby <jslaby@suse.cz> Reported-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serial: altera_uart: call iounmap() at driver removeTobias Klauser2017-05-251-0/+1
| | | | | | | | | | | | | | | | | | | | | | The driver calls ioremap() in the probe function but doesn't call iounmap() in the remove function correspondingly. Do so now. Follow commit 5c9d6abed9e0 ("serial: altera_jtaguart: adding iounmap()") Cc: Alexey Khoroshilov <khoroshilov@ispras.ru> Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serial: imx: ensure UCR3 and UFCR are setup correctlyUwe Kleine-König2017-05-251-2/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit e61c38d85b73 ("serial: imx: setup DCEDTE early and ensure DCD and RI irqs to be off") has a flaw: While UCR3 and UFCR were modified using read-modify-write before it switched to write register values independent of the previous state. That's a good idea in principle (and that's why I did it) but needs more care. This patch reinstates read-modify-write for UFCR and for UCR3 ensures that RXDMUXSEL and ADNIMP are set for post imx1. Fixes: e61c38d85b73 ("serial: imx: setup DCEDTE early and ensure DCD and RI irqs to be off") Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Mika Penttilä <mika.penttila@nextfour.com> Tested-by: Mika Penttilä <mika.penttila@nextfour.com> Acked-by: Steve Twiss <stwiss.opensource@diasemi.com> Tested-by: Steve Twiss <stwiss.opensource@diasemi.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serial: enable serdev supportJohan Hovold2017-05-181-2/+2
| | | | | | | | | | | | | | | | Enable serdev support by using the new device-registration helpers. Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | tty/serdev: add serdev registration interfaceJohan Hovold2017-05-182-2/+79
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a new interface for registering a serdev controller and clients, and a helper function to deregister serdev devices (or a tty device) that were previously registered using the new interface. Once every driver currently using the tty_port_register_device() helpers have been vetted and converted to use the new serdev registration interface (at least for deregistration), we can move serdev registration to the current helpers and get rid of the serdev-specific functions. Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serdev: Restore serdev_device_write_buf for atomic contextStefan Wahren2017-05-181-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | Starting with commit 6fe729c4bdae ("serdev: Add serdev_device_write subroutine") the function serdev_device_write_buf cannot be used in atomic context anymore (mutex_lock is sleeping). So restore the old behavior. Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Fixes: 6fe729c4bdae ("serdev: Add serdev_device_write subroutine") Acked-by: Rob Herring <robh@kernel.org> Reviewed-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serial: core: fix crash in uart_suspend_portLucas Stach2017-05-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | With serdev we might end up with serial ports that have no cdev exported to userspace, as they are used as the bus interface to other devices. In that case serial_match_port() won't be able to find a matching tty_dev. Skip the irq wakeup enabling in that case, as serdev will make sure to keep the port active, as long as there are devices depending on it. Fixes: 8ee3fde04758 (tty_port: register tty ports with serdev bus) Signed-off-by: Lucas Stach <l.stach@pengutronix.de> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | tty: fix port buffer lockingVegard Nossum2017-05-181-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | tty_insert_flip_string_fixed_flag() is racy against itself when called from the ioctl(TCXONC, TCION/TCIOFF) path [1] and the flush_to_ldisc() workqueue path [2]. The problem is that port->buf.tail->used is modified without consistent locking; the ioctl path takes tty->atomic_write_lock, whereas the workqueue path takes ldata->output_lock. We cannot simply take ldata->output_lock, since that is specific to the N_TTY line discipline. It might seem natural to try to take port->buf.lock inside tty_insert_flip_string_fixed_flag() and friends (where port->buf is actually used/modified), but this creates problems for flush_to_ldisc() which takes it before grabbing tty->ldisc_sem, o_tty->termios_rwsem, and ldata->output_lock. Therefore, the simplest solution for now seems to be to take tty->atomic_write_lock inside tty_port_default_receive_buf(). This lock is also used in the write path [3] with a consistent ordering. [1]: Call Trace: tty_insert_flip_string_fixed_flag pty_write tty_send_xchar // down_read(&o_tty->termios_rwsem) // mutex_lock(&tty->atomic_write_lock) n_tty_ioctl_helper n_tty_ioctl tty_ioctl // down_read(&tty->ldisc_sem) do_vfs_ioctl SyS_ioctl [2]: Workqueue: events_unbound flush_to_ldisc Call Trace: tty_insert_flip_string_fixed_flag pty_write tty_put_char __process_echoes commit_echoes // mutex_lock(&ldata->output_lock) n_tty_receive_buf_common n_tty_receive_buf2 tty_ldisc_receive_buf // down_read(&o_tty->termios_rwsem) tty_port_default_receive_buf // down_read(&tty->ldisc_sem) flush_to_ldisc // mutex_lock(&port->buf.lock) process_one_work [3]: Call Trace: tty_insert_flip_string_fixed_flag pty_write n_tty_write // mutex_lock(&ldata->output_lock) // down_read(&tty->termios_rwsem) do_tty_write (inline) // mutex_lock(&tty->atomic_write_lock) tty_write // down_read(&tty->ldisc_sem) __vfs_write vfs_write SyS_write The bug can result in about a dozen different crashes depending on what exactly gets corrupted when port->buf.tail->used points outside the buffer. The patch passes my LOCKDEP/PROVE_LOCKING testing but more testing is always welcome. Found using syzkaller. Cc: <stable@vger.kernel.org> Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | tty: ehv_bytechan: clean up init error handlingJohan Hovold2017-05-181-9/+8
| | | | | | | | | | | | | | | | | | | | Straighten out the initcall error handling to avoid deregistering a never-registered tty driver (something which would lead to a NULL-pointer dereference) in the most unlikely event that driver registration fails (e.g. we've run out of major numbers). Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serial: ifx6x60: fix use-after-free on module unloadJohan Hovold2017-05-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | Make sure to deregister the SPI driver before releasing the tty driver to avoid use-after-free in the SPI remove callback where the tty devices are deregistered. Fixes: 72d4724ea54c ("serial: ifx6x60: Add modem power off function in the platform reboot process") Cc: stable <stable@vger.kernel.org> # 3.8 Cc: Jun Chen <jun.d.chen@intel.com> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serial: altera_jtaguart: adding iounmap()Alexey Khoroshilov2017-05-181-0/+1
| | | | | | | | | | | | | | | | | | | | | | The driver does ioremap(port->mapbase, ALTERA_JTAGUART_SIZE), but there is no any iounmap(). Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Acked-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serial: exar: Fix stuck MSIsJan Kiszka2017-05-181-9/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After migrating 8250_exar to MSI in 172c33cb61da, we can get stuck without further interrupts because of the special wake-up event these chips send. They are only cleared by reading INT0. As we fail to do so during startup and shutdown, we can leave the interrupt line asserted, which is fatal with edge-triggered MSIs. Add the required reading of INT0 to startup and shutdown. Also account for the fact that a pending wake-up interrupt means we have to return 1 from exar_handle_irq. Drop the unneeded reading of INT1..3 along with this - those never reset anything. An alternative approach would have been disabling the wake-up interrupt. Unfortunately, this feature (REGB[17] = 1) is not available on the XR17D15X. Fixes: 172c33cb61da ("serial: exar: Enable MSI support") Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serial: efm32: Fix parity management in 'efm32_uart_console_get_options()'Christophe JAILLET2017-05-181-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | UARTn_FRAME_PARITY_ODD is 0x0300 UARTn_FRAME_PARITY_EVEN is 0x0200 So if the UART is configured for EVEN parity, it would be reported as ODD. Fix it by correctly testing if the 2 bits are set. Fixes: 3afbd89c9639 ("serial/efm32: add new driver") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serdev: fix tty-port client deregistrationJohan Hovold2017-05-181-5/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The port client data must be set when registering the serdev controller or client deregistration will fail (and the serdev devices are left registered and allocated) if the port was never opened in between. Make sure to clear the port client data on any probe errors to avoid a use-after-free when the client is later deregistered unconditionally (e.g. in a tty-port deregistration helper). Also move port client operation initialisation to registration. Note that the client ops must be restored on failed probe. Fixes: bed35c6dfa6a ("serdev: add a tty port controller driver") Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Rob Herring <robh@kernel.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
OpenPOWER on IntegriCloud