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2018-03-14devpts: resolve devpts bind-mountsChristian Brauner1-10/+16
Most libcs will still look at /dev/ptmx when opening the master fd of a pty device. When /dev/ptmx is a bind-mount of /dev/pts/ptmx and the TIOCGPTPEER ioctl() is used to safely retrieve a file descriptor for the slave side of the pty based on the master fd, the /proc/self/fd/{0,1,2} symlinks will point to /. A very simply reproducer for this issue presupposing a libc that uses TIOCGPTPEER in its openpty() implementation is: unshare --mount mount --bind /dev/pts/ptmx /dev/ptmx chmod 666 /dev/ptmx script ls -al /proc/self/fd/0 Having bind-mounts of /dev/pts/ptmx to /dev/ptmx not working correctly is a regression. In addition, it is also a fairly common scenario in containers employing user namespaces. The reason for the current failure is that the kernel tries to verify the useability of the devpts filesystem without resolving the /dev/ptmx bind-mount first. This will lead it to detect that the dentry is escaping its bind-mount. The reason is that while the devpts filesystem mounted at /dev/pts has the devtmpfs mounted at /dev as its parent mount: 21 -- -- / /dev -- 21 -- / /dev/pts devtmpfs and devpts are on different devices -- -- 0:6 / /dev -- -- 0:20 / /dev/pts This has the consequence that the pathname of the parent directory of the devpts filesystem mount at /dev/pts is /. So if /dev/ptmx is a bind-mount of /dev/pts/ptmx then the /dev/ptmx bind-mount and the devpts mount at /dev/pts will end up being located on the same device which is recorded in the superblock of their vfsmount. This means the parent directory of the /dev/ptmx bind-mount will be /ptmx: -- -- ---- /ptmx /dev/ptmx Without the bind-mount resolution patch the kernel will now perform the bind-mount escape check directly on /dev/ptmx. The function responsible for this is devpts_ptmx_path() which calls pts_path() which in turn calls path_parent_directory(). Based on the above explanation, path_parent_directory() will yield / as the parent directory for the /dev/ptmx bind-mount and not the expected /dev. Thus, the kernel detects that /dev/ptmx is escaping its bind-mount and will set /proc/<pid>/fd/<nr> to /. This patch changes the logic to first resolve any bind-mounts. After the bind-mounts have been resolved (i.e. we have traced it back to the associated devpts mount) devpts_ptmx_path() can be called. In order to guarantee correct path generation for the slave file descriptor the kernel now requires that a pts directory is found in the parent directory of the ptmx bind-mount. This implies that when doing bind-mounts the ptmx bind-mount and the devpts mount should have a common parent directory. A valid example is: mount -t devpts devpts /dev/pts mount --bind /dev/pts/ptmx /dev/ptmx an invalid example is: mount -t devpts devpts /dev/pts mount --bind /dev/pts/ptmx /ptmx This allows us to support: - calling open on ptmx devices located inside non-standard devpts mounts: mount -t devpts devpts /mnt master = open("/mnt/ptmx", ...); slave = ioctl(master, TIOCGPTPEER, ...); - calling open on ptmx devices located outside the devpts mount with a common ancestor directory: mount -t devpts devpts /dev/pts mount --bind /dev/pts/ptmx /dev/ptmx master = open("/dev/ptmx", ...); slave = ioctl(master, TIOCGPTPEER, ...); while failing on ptmx devices located outside the devpts mount without a common ancestor directory: mount -t devpts devpts /dev/pts mount --bind /dev/pts/ptmx /ptmx master = open("/ptmx", ...); slave = ioctl(master, TIOCGPTPEER, ...); in which case save path generation cannot be guaranteed. Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Suggested-by: Eric Biederman <ebiederm@xmission.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-14devpts: hoist out check for DEVPTS_SUPER_MAGICChristian Brauner1-11/+15
Hoist the check whether we have already found a suitable devpts filesystem out of devpts_ptmx_path() in preparation for the devpts bind-mount resolution patch. This is a non-functional change. Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: 8250: Add Nuvoton NPCM UARTJoel Stanley4-0/+38
The Nuvoton UART is almost compatible with the 8250 driver when probed via the 8250_of driver, however it requires some extra configuration at startup. Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Joel Stanley <joel@jms.id.au> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: mxs-auart: disable clks of Alphascale ASM9260Alexey Khoroshilov1-13/+23
In case of Alphascale ASM9260 probe() enables s->clk and s->clk_ahb via mxs_get_clks(), but there is no disable of the clocks. The patch adds it to error paths and to mxs_auart_remove(). Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Fixes: 254da0d753fb ("serial: mxs-auart: add Alphascale ASM9260 support") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: 8250_dw: Switch to use acpi_dev_present()Andy Shevchenko1-11/+5
Special settings for APMC0D08 are applied when device is present in the system. To check its presence we may use acpi_dev_present() instead of current open coded variant. Cc: Feng Kan <fkan@apm.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: imx: consistently use imx_uart_ as prefix for all functionsUwe Kleine-König1-213/+213
Having a fixed prefix helps at several places. It ensures that another driver doesn't use the same function name which confuses the linker and tools like ctags. It simplifies working with function tracing and dynamic printk() support which can filter on function names. And last but not least it helps the human source code reader to understand if a given function belongs to a driver or a more general part of the kernel. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: imx: don't prepare to send if no data is availableUwe Kleine-König1-0/+3
serial_core might call the .start_tx callback without any data being available to send. In this case return early instead of going through all the setup needed for sending which might include disabling RX in RS485 half-duplex mode. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: imx: Fix handling of TC irq in combination with DMAUwe Kleine-König1-6/+20
When using RS485 half duplex the Transmitter Complete irq is needed to determine the moment when the transmitter can be disabled. When using DMA this irq must only be enabled when DMA has completed to transfer all data. Otherwise the CPU might busily trigger this irq which is not properly handled and so the also pending irq for the DMA transfer cannot trigger. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: imx: Also enable the aging timer in PIO modeUwe Kleine-König1-3/+12
This allows to increase the RX waterlevel which allows to delay the RRDY irq. The desired effect is that less irqs are needed to handle characters and so reduce irq count of the system. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: imx: ensure that RX irqs are off if RX is offUwe Kleine-König1-28/+64
Make sure that UCR1.RXDMAEN and UCR1.ATDMAEN (for the DMA case) and UCR1.RRDYEN (for the PIO case) are off iff UCR1.RXEN is disabled. This ensures that the fifo isn't read with RX disabled which results in an exception. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: imx: Stop to receive in .stop_rx()Uwe Kleine-König1-9/+0
When the UART is used in DMA mode, .stop_rx() does nothing if the port isn't suspended. This is wrong as .stop_rx() should stop receiving characters unconditionally. When the port is about to be closed the DMA channel is stopped in .shutdown(), so this isn't necessary to be in .stop_rx() here, too. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: imx: setup fifo waterlevel before enabling aging timerUwe Kleine-König1-2/+2
The aging timer fires if there are characters in the RX fifo but the water level isn't reached yet. Make sure that the waterlevel is configured before the aging timer is enabled to trigger a DMA request (UCR1_ATDMAEN). Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: imx: use u32 variables with matching names for registersUwe Kleine-König1-167/+179
The serial/imx driver is full of inconsistently named and typed variables that hold different register values. Consistently use u32 as type (matching what readl and writel use) and name the variables after the register whose value they are holding. This makes it easier to notice when UCR2_RTSEN is written to UCR1. The only difference introduced by this commit in the compiled driver is that twice the second argument to warn_slowpath_null() changed because the two WARN_ON in dma_rx_callback() pass __LINE__ to warn_slowpath_null(). Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: imx: simplify check that prevents starting PIO when DMA is in useUwe Kleine-König1-2/+1
The original code looks as follows: if (sport->dma_is_enabled) { ... make sure TX DMA is running, i.e. .dma_is_txing = 1 } if (sport->dma_is_txing) return; As .dma_is_txing can only be true if .dma_is_enabled is, the return can go at the end of the first if body without an additional check. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: imx: simplify some conditions related to dmaUwe Kleine-König1-3/+3
Neither .dma_is_txing nor .dma_is_rxing can evaluate to true if .dma_is_enabled evaluates to false: The only function that sets .dma_is_txing to a non-zero value is imx_dma_tx() which is only called if .dma_is_enabled is true. Same for .dma_is_rxing and start_rx_dma(). And before .dma_is_enabled is set to 0 when imx_shutdown calls imx_disable_dma(), .dma_is_rxing and .dma_is_txing are reset to zero before, too. For this reason sport->dma_is_enabled && sport->dma_is_rxing has the same value as sport->dma_is_rxing which allows to simplify three if conditions. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: imx: implement shadow registers for UCRx and UFCRUwe Kleine-König1-1/+59
This reduces the amount of read accesses to the register space by shadowing the values for five registers that only change on writing them. There is a single bit in UCR2 that might change without being written to it, this is handled accordingly. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: imx: add wrappers for writel and readlUwe Kleine-König1-184/+199
This prepares implementing shadow copies for the control registers and additionally provides a good place to hook in debug code to trace register usage. Most of this patch was done using pattern substitution: perl -p -i -e ' s/\breadl(?:_relaxed)?\((?:sport->port\.|port->)membase \+/imx_uart_readl(sport,/; s/\bwritel(?:_relaxed)?\(([^,]*), (sport->port\.|port->)membase \+/imx_uart_writel(sport, $1,/; ' drivers/tty/serial/imx.c Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09tty: New RISC-V SBI console driverPalmer Dabbelt3-0/+71
The RISC-V ISA defines a simple console that is availiable via SBI calls on all systems. The SBI console is designed to be availiable at all times, so while it's most natural to use this as an early printk target it's also possible to use this as the system console when there isn't a better one availiable. This patch adds support for the RISC-V SBI console via the HVC infastructure. It's entirely independent from our early printk support, which results in early boot messages appearing twice over the SBI console. As far as I can tell that's the fault of our early printk support (we should support earlycon) as opposed to this driver. There is one checkpatch.pl warning here: to check the MAINTAINERS file. They're all matched by the "K: riscv" line. Signed-off-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: imx: document functions that are called with port.lock takenUwe Kleine-König1-12/+11
Consistently indicate being called with irqs off and the port lock taken for all functions that this applies to. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: imx: Rename register fields to match newer reference manualsUwe Kleine-König1-9/+9
Only the reference manual for the i.MX1 (I have MC9328MX1RM/D Rev 5 from 2004) uses TDMAEN and RDMAEN for these. All reference manuals for the newer chips use TXDMAEN and RXDMAEN. Update to the newer name with the assumption that most imx users don't use an imx1 any more. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial, pci_ids: Move duplicate IDs to PCI IDs databaseAndy Shevchenko3-6/+3
PCI ID database is for IDs used across several drivers. Here is the case for SUNIX combo cards. No functional change intended. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: xuartps: Fix out-of-bounds access through DT aliasGeert Uytterhoeven1-1/+1
The cdns_uart_port[] array is indexed using a value derived from the "serialN" alias in DT, which may lead to an out-of-bounds access. Fix this by adding a range check. Fixes: 928e9263492069ee ("tty: xuartps: Initialize ports according to aliases") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: sirf: Fix out-of-bounds access through DT aliasGeert Uytterhoeven1-0/+5
The sirf_ports[] array is indexed using a value derived from the "serialN" alias in DT, which may lead to an out-of-bounds access. Fix this by adding a range check. Fixes: a6ffe8966acbb66b ("serial: sirf: use dynamic method allocate uart structure") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: sh-sci: Fix out-of-bounds access through DT aliasGeert Uytterhoeven1-0/+4
The sci_ports[] array is indexed using a value derived from the "serialN" alias in DT, which may lead to an out-of-bounds access. Fix this by adding a range check. Note that the array size is defined by a Kconfig symbol (CONFIG_SERIAL_SH_SCI_NR_UARTS), so this can even be triggered using a legitimate DTB. Fixes: 97ed9790c514066b ("serial: sh-sci: Remove unused platform data capabilities field") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: samsung: Fix out-of-bounds access through serial port indexGeert Uytterhoeven1-0/+4
The s3c24xx_serial_ports[] array is indexed using a value derived from the "serialN" alias in DT, or from an incrementing probe index, which may lead to an out-of-bounds access. Fix this by adding a range check. Note that the array size is defined by a Kconfig symbol (CONFIG_SERIAL_SAMSUNG_UARTS), so this can even be triggered using a legitimate DTB or legitimate board code. Fixes: 13a9f6c64fdc55eb ("serial: samsung: Consider DT alias when probing ports") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: pxa: Fix out-of-bounds access through serial port indexGeert Uytterhoeven1-0/+4
The serial_pxa_ports[] array is indexed using a value derived from the "serialN" alias in DT, or from platform data, which may lead to an out-of-bounds access. Fix this by adding a range check. Fixes: 699c20f3e6310aa2 ("serial: pxa: add OF support") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: mxs-auart: Fix out-of-bounds access through serial port indexGeert Uytterhoeven1-0/+4
The auart_port[] array is indexed using a value derived from the "serialN" alias in DT, or from platform data, which may lead to an out-of-bounds access. Fix this by adding a range check. Fixes: 1ea6607d4cdc9179 ("serial: mxs-auart: Allow device tree probing") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: imx: Fix out-of-bounds access through serial port indexGeert Uytterhoeven1-0/+6
The imx_ports[] array is indexed using a value derived from the "serialN" alias in DT, or from platform data, which may lead to an out-of-bounds access. Fix this by adding a range check. Fixes: ff05967a07225ab6 ("serial/imx: add of_alias_get_id() reference back") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: fsl_lpuart: Fix out-of-bounds access through DT aliasGeert Uytterhoeven1-0/+4
The lpuart_ports[] array is indexed using a value derived from the "serialN" alias in DT, which may lead to an out-of-bounds access. Fix this by adding a range check. Fixes: c9e2e946fb0ba5d2 ("tty: serial: add Freescale lpuart driver support") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: arc_uart: Fix out-of-bounds access through DT aliasGeert Uytterhoeven1-0/+5
The arc_uart_ports[] array is indexed using a value derived from the "serialN" alias in DT, which may lead to an out-of-bounds access. Fix this by adding a range check. Note that the array size is defined by a Kconfig symbol (CONFIG_SERIAL_ARC_NR_PORTS), so this can even be triggered using a legitimate DTB. Fixes: ea28fd56fcde69af ("serial/arc-uart: switch to devicetree based probing") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: imx: drop check for enabled dma in .startupUwe Kleine-König1-1/+1
imx_shutdown() calls imx_disable_dma if .dma_is_enabled. So after imx_shudown() completes, .dma_is_enabled is zero. For this reason .dma_is_enabled is also zero when imx_startup() is called. So the check for this variable being zero can be dropped. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Shawn Guo <shawnguo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: imx: simplify tracking of dma being initializedUwe Kleine-König1-8/+4
The .dma_is_inited member is only set to a value != 0 when the port's startup function calls imx_uart_dma_init(). On shutdown of the port imx_uart_dma_exit is called which sets the value back to 0. So .dma_is_inited is always 0 when imx_startup() is called (assuming .startup() and .shutdown() are correctly balanced) and the check for !sport->dma_is_inited can go away. This allows to replace .dma_is_inited by a variable local to imx_startup. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Shawn Guo <shawnguo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: imx: Only handle irqs that are actually enabledUwe Kleine-König1-6/+32
Handling an irq that isn't enabled can have some undesired side effects. Some of these are mentioned in the newly introduced code comment. Some of the irq sources already had their handling right, some don't. Handle them all in the same consistent way. The change for USR1_RRDY and USR1_AGTIM drops the check for dma_is_enabled. This is correct as UCR1_RRDYEN and UCR2_ATEN are always off if dma is enabled. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Shawn Guo <shawnguo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: imx: rename variables to match the register namesUwe Kleine-König1-11/+10
Now the variable holding the value of register USR1 is called usr1 instead of sts which is more straight forward. The same is also done for sts2 which is called usr2 now. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Shawn Guo <shawnguo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: imx: drop if that always evaluates to trueUwe Kleine-König1-2/+1
The check sts & USR1_DTRD was just evaluated to true two lines above. So this change doesn't have any effect on the semantic of the driver. Fixes: 27e16501052e ("serial: imx: implement DSR irq handling for DTE mode") Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Shawn Guo <shawnguo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: mvebu-uart: remove duplicated bit-wise or of STAT_FRM_ERRColin Ian King1-1/+1
Bit pattern STAT_FRM_ERR is being bit-wise or'd twice; remove the redundant 2nd STAT_FRM_ERR Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28tty: serial: imx: allow breaks to be received when using dmaTroy Kisky1-7/+14
This allows me to login after sending a break when service serial-getty@ttymxc0.service is running The "tty_insert_flip_char(port, 0, TTY_BREAK)" in clear_rx_errors fixes this by allowing the higher layers to see a break. Also, call uart_handle_break to handle possible "secure attention key." FYI: Martin said the ROM sdma firmware works with this patch, but external sdma firmware still does not send breaks on a i.mx6UL Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com> Tested-by: Martin Hicks <mort@bork.org> Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: 8250_dw: Allow TX FIFO to drain before writing to UART_LCRJoshua Scott1-0/+18
An issue has been observed on the Marvell Armada 38x serial port. Writes to UART_LCR can result in characters that are currently held in the TX FIFO being lost rather than sent, even if the userspace process has attempted to flush them. This is most visible when using the "resize" command (tested on Busybox), where we have observed the escape code for restoring cursor position becoming mangled. Signed-off-by: Joshua Scott <joshua.scott@alliedtelesis.co.nz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: sh-sci: use hrtimer for receive timeoutUlrich Hecht1-17/+30
High latencies of classic timers cause performance issues for high- speed serial transmissions. This patch transforms rx_timer into an hrtimer to reduce the minimum latency. Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: 8250: 8250_omap: Fix throttling when DMA is enabledVignesh R1-1/+10
omap_8250_throttle() is called when tty RX buffer is about to overflow and can no longer keep up with the rate at which UART is receiving data. So, the expectation of this callback, is that UART stops RX and asserts HW flow control to signal the sender to stop sending more data. omap_8250_throttle() disables RX FIFO interrupts thus FIFO is no longer serviced, leading to assertion of flow control once RX FIFO is full. But, this does not work when DMA is enabled as driver keeps queuing new RX DMA request in completion handler without brothering about throttling request made by the higher layer. This patch introduces a flag that can be used to determine whether or not to queue next RX DMA request based on throttling request. Without this patch, tty buffer overflows are reported at higher baudrates. Signed-off-by: Vignesh R <vigneshr@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: 8250: Don't service RX FIFO if interrupts are disabledVignesh R1-1/+2
Currently, data in RX FIFO is read based on UART_LSR register state even if RDI and RLSI interrupts are disabled in UART_IER register. This is because when IRQ handler is called due to TX FIFO empty event, RX FIFO is serviced based on UART_LSR register status instead of UART_IIR status. This defeats the purpose of disabling UART RX FIFO interrupts during throttling(see, omap_8250_throttle()) as IRQ handler continues to drain UART RX FIFO resulting in overflow of buffer at tty layer. Fix this by making sure that driver drains UART RX FIFO only when UART_IIR_RDI is set along with UART_LSR_BI or UART_LSR_DR bits. Signed-off-by: Vignesh R <vigneshr@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28DT: serial: renesas,sci-serial: document R8A77980 bindingsSergei Shtylyov1-0/+2
R-Car V3H (R8A77980) SoC has the R-Car gen3 compatible SCIF and HSCIF ports, so document the SoC specific bindings. Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Reviewed-by: Rob Herring <robh@kernel.org> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28gpio: serial: max310x: Use HW type for gpio_chip's labelJan Kundrát1-1/+1
Some debugging tools (/sys/kernel/debug/gpio, `lsgpio`) use the gpio_chip's label for displaying an additional context. Right now, the information duplicates stuff which is already available from the parent's device. This is how e.g. `lsgpio`'s output looks like: GPIO chip: gpiochip2, "spi1.2", 16 GPIO lines Comparing the output of other GPIO expanders that I have available: gpiochip4: GPIOs 464-479, parent: spi/spi1.1, mcp23s17, can sleep: gpiochip5: GPIOs 448-463, parent: i2c/0-0020, pca9555, can sleep: gpiochip2: GPIOs 496-511, parent: spi/spi1.2, spi1.2, can sleep: This patch ensures that the type of the real HW device is shown instead of duplicating the SPI path: gpiochip2: GPIOs 496-511, parent: spi/spi1.2, MAX14830, can sleep: Signed-off-by: Jan Kundrát <jan.kundrat@cesnet.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: altera: set RRDY flag also without irqUwe Kleine-König1-10/+10
The UART can be operated without an irq. In this case a timer is setup that regularily calls altera_uart_interrupt(). The receiving part depends on pp->imr having the bit ALTERA_UART_STATUS_RRDY_MSK set, otherwise altera_uart_rx_chars() is never called. So ensure that the bit gets set (disguised as ALTERA_UART_CONTROL_RRDY_MSK) by not returning early from altera_uart_startup() if port->irq is 0. This doesn't affect the hardware as the ALTERA_UART_CONTROL_RRDY_MSK bit isn't actually written to the control register. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: altera: don't enable any irq if the device doesn't feature an irqUwe Kleine-König1-8/+22
If the irq line of an altera UART device isn't used to report interrupts for this device the driver better ensures that this device doesn't pull this line to active state and so disturb the whatever might be connected to this line. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: altera: ensure port->regshift is honored consistentlyUwe Kleine-König1-6/+6
Most register accesses in the altera driver honor port->regshift by using altera_uart_writel(). There are a few accesses however that were missed when the driver was converted to use port->regshift and some others were added later in commit 4d9d7d896d77 ("serial: altera_uart: add earlycon support"). Fixes: 2780ad42f5fe ("tty: serial: altera_uart: Use port->regshift to store bus shift") Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28console: Drop added "static" for newport_conKees Cook1-1/+1
Commit 4fe505119778 ("console: Expand dummy functions for CFI") accidentally added "static" to newport_con instance of struct consw, while trying to normalize the declarations. This, however, needed to stay non-static as it has an extern. Reported-by: kbuild test robot <fengguang.wu@intel.com> Fixes: 4fe505119778 ("console: Expand dummy functions for CFI") Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-27console: Expand dummy functions for CFIKees Cook5-48/+121
This expands the no-op dummy functions into full prototypes to avoid indirect call mismatches when running under Control Flow Integrity checking, like with Clang's -fsanitize=cfi. Co-Developed-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-27console: Fill in struct consw argument namesKees Cook1-26/+32
Reading the function declarations for the console callbacks lacks any hints as to what the arguments are. Instead of going and digging around in various implementations that may each only have a subset of the callbacks, name all the arguments in the declaration. This has no functional change. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-27console: SisUSB2VGA: Drop dummy con_font_get()Kees Cook1-1/+0
As done in commit: 724ba8b30b04 ("console/dummy: leave .con_font_get set to NULL") This drops the dummy .con_font_get(), as it could leave arguments uninitialized. Cc: Thomas Winischhofer <thomas@winischhofer.net> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>