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2019-01-22serial: fsl_lpuart: fix maximum acceptable baud rate with over-samplingTomonori Sakita
Using over-sampling ratio, lpuart can accept baud rate upto uartclk / 4. Signed-off-by: Tomonori Sakita <tomonori.sakita@sord.co.jp> Signed-off-by: Atsushi Nemoto <atsushi.nemoto@sord.co.jp> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-22tty: serial: qcom_geni_serial: Allow mctrl when flow control is disabledMatthias Kaehlcke
The geni set/get_mctrl() functions currently do nothing unless hardware flow control is enabled. Remove this arbitrary limitation. Suggested-by: Johan Hovold <johan@kernel.org> Fixes: 8a8a66a1a18a ("tty: serial: qcom_geni_serial: Add support for flow control") Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Reviewed-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-18serial: 8250: Fix serial8250 initialization crashHe Zhe
The initialization code of interrupt backoff work might reference NULL pointer and cause the following crash, if no port was found. [ 10.017727] CPU 0 Unable to handle kernel paging request at virtual address 000001b0, epc == 807088e0, ra == 8070863c ---- snip ---- [ 11.704470] [<807088e0>] serial8250_register_8250_port+0x318/0x4ac [ 11.747251] [<80708d74>] serial8250_probe+0x148/0x1c0 [ 11.789301] [<80728450>] platform_drv_probe+0x40/0x94 [ 11.830515] [<807264f8>] really_probe+0xf8/0x318 [ 11.870876] [<80726b7c>] __driver_attach+0x110/0x12c [ 11.910960] [<80724374>] bus_for_each_dev+0x78/0xcc [ 11.951134] [<80725958>] bus_add_driver+0x200/0x234 [ 11.989756] [<807273d8>] driver_register+0x84/0x148 [ 12.029832] [<80d72f84>] serial8250_init+0x138/0x198 [ 12.070447] [<80100e6c>] do_one_initcall+0x5c/0x2a0 [ 12.110104] [<80d3a208>] kernel_init_freeable+0x370/0x484 [ 12.150722] [<80a49420>] kernel_init+0x10/0xf8 [ 12.191517] [<8010756c>] ret_from_kernel_thread+0x14/0x1c This patch makes sure the initialization code can be reached only if a port is found. Fixes: 6d7f677a2afa ("serial: 8250: Rate limit serial port rx interrupts during input overruns") Signed-off-by: He Zhe <zhe.he@windriver.com> Reviewed-by: Darwin Dingel <darwin.dingel@alliedtelesis.co.nz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-18uart: Fix crash in uart_write and uart_put_charSamir Virmani
We were experiencing a crash similar to the one reported as part of commit:a5ba1d95e46e ("uart: fix race between uart_put_char() and uart_shutdown()") in our testbed as well. We continue to observe the same crash after integrating the commit a5ba1d95e46e ("uart: fix race between uart_put_char() and uart_shutdown()") On reviewing the change, the port lock should be taken prior to checking for if (!circ->buf) in fn. __uart_put_char and other fns. that update the buffer uart_state->xmit. Traceback: [11/27/2018 06:24:32.4870] Unable to handle kernel NULL pointer dereference at virtual address 0000003b [11/27/2018 06:24:32.4950] PC is at memcpy+0x48/0x180 [11/27/2018 06:24:32.4950] LR is at uart_write+0x74/0x120 [11/27/2018 06:24:32.4950] pc : [<ffffffc0002e6808>] lr : [<ffffffc0003747cc>] pstate: 000001c5 [11/27/2018 06:24:32.4950] sp : ffffffc076433d30 [11/27/2018 06:24:32.4950] x29: ffffffc076433d30 x28: 0000000000000140 [11/27/2018 06:24:32.4950] x27: ffffffc0009b9d5e x26: ffffffc07ce36580 [11/27/2018 06:24:32.4950] x25: 0000000000000000 x24: 0000000000000140 [11/27/2018 06:24:32.4950] x23: ffffffc000891200 x22: ffffffc01fc34000 [11/27/2018 06:24:32.4950] x21: 0000000000000fff x20: 0000000000000076 [11/27/2018 06:24:32.4950] x19: 0000000000000076 x18: 0000000000000000 [11/27/2018 06:24:32.4950] x17: 000000000047cf08 x16: ffffffc000099e68 [11/27/2018 06:24:32.4950] x15: 0000000000000018 x14: 776d726966205948 [11/27/2018 06:24:32.4950] x13: 50203a6c6974755f x12: 74647075205d3333 [11/27/2018 06:24:32.4950] x11: 3a35323a36203831 x10: 30322f37322f3131 [11/27/2018 06:24:32.4950] x9 : 5b205d303638342e x8 : 746164206f742070 [11/27/2018 06:24:32.4950] x7 : 7520736920657261 x6 : 000000000000003b [11/27/2018 06:24:32.4950] x5 : 000000000000817a x4 : 0000000000000008 [11/27/2018 06:24:32.4950] x3 : 2f37322f31312a5b x2 : 000000000000006e [11/27/2018 06:24:32.4950] x1 : ffffffc0009b9cf0 x0 : 000000000000003b [11/27/2018 06:24:32.4950] CPU2: stopping [11/27/2018 06:24:32.4950] CPU: 2 PID: 0 Comm: swapper/2 Tainted: P D O 4.1.51 #3 [11/27/2018 06:24:32.4950] Hardware name: Broadcom-v8A (DT) [11/27/2018 06:24:32.4950] Call trace: [11/27/2018 06:24:32.4950] [<ffffffc0000883b8>] dump_backtrace+0x0/0x150 [11/27/2018 06:24:32.4950] [<ffffffc00008851c>] show_stack+0x14/0x20 [11/27/2018 06:24:32.4950] [<ffffffc0005ee810>] dump_stack+0x90/0xb0 [11/27/2018 06:24:32.4950] [<ffffffc00008e844>] handle_IPI+0x18c/0x1a0 [11/27/2018 06:24:32.4950] [<ffffffc000080c68>] gic_handle_irq+0x88/0x90 Fixes: a5ba1d95e46e ("uart: fix race between uart_put_char() and uart_shutdown()") Cc: stable <stable@vger.kernel.org> Signed-off-by: Samir Virmani <samir@embedur.com> Acked-by: Tycho Andersen <tycho@tycho.ws> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-14Merge tag 'tty-5.0-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial fixes from Greg KH: "Here are 2 tty and serial fixes for 5.0-rc2 that resolve some reported issues. The first is a simple serial driver fix for a regression that showed up in 5.0-rc1. The second one resolves a number of reported issues with the recent tty locking fixes that went into 5.0-rc1. Lots of people have tested the second one and say it resolves their issues. Both have been in linux-next with no reported issues" * tag 'tty-5.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: tty: Don't hold ldisc lock in tty_reopen() if ldisc present serial: lantiq: Do not swap register read/writes
2019-01-09tty/serial: Add RISC-V SBI earlycon supportAnup Patel
In RISC-V, the M-mode runtime firmware provide SBI calls for debug prints. This patch adds earlycon support using RISC-V SBI console calls. To enable it, just pass "earlycon=sbi" in kernel parameters. Signed-off-by: Anup Patel <anup@brainfault.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-01-08serial: lantiq: Do not swap register read/writesHauke Mehrtens
The ltq_r32() and ltq_w32() macros use the __raw_readl() and __raw_writel() functions which do not swap the value to little endian. On the big endian vrx200 SoC the UART is operated in big endian IO mode, the readl() and write() functions convert the value to little endian first and then the driver does not work any more on this SoC. Currently the vrx200 SoC selects the CONFIG_SWAP_IO_SPACE option, without this option the serial driver would work, but PCI devices do not work any more. This patch makes the driver use the __raw_readl() and __raw_writel() functions which do not swap the endianness. On big endian system it is assumed that the device should be access in big endian IO mode and on a little endian system it would be access in little endian mode. Fixes: 89b8bd2082bb ("serial: lantiq: Use readl/writel instead of ltq_r32/ltq_w32") Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de> Acked-by: John Crispin <john@phrozen.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-05Merge tag 'armsoc-late' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc Pull more ARM SoC updates from Olof Johansson: "A few updates that we merged late but are low risk for regressions for other platforms (and a few other straggling patches): - I mis-tagged the 'drivers' branch, and missed 3 patches. Merged in here. They're for a driver for the PL353 SRAM controller and a build fix for the qualcomm scm driver. - A new platform, RDA Micro RDA8810PL (Cortex-A5 w/ integrated Vivante GPU, 256MB RAM, Wifi). This includes some acked platform-specific drivers (serial, etc). This also include DTs for two boards with this SoC, OrangePi 2G and OrangePi i86. - i.MX8 is another new platform (NXP, 4x Cortex-A53 + Cortex-M4, 4K video playback offload). This is the first i.MX 64-bit SoC. - Some minor updates to Samsung boards (adding a few peripherals in DTs). - Small rework for SMP bootup on STi platforms. - A couple of TEE driver fixes. - A couple of new config options (bcm2835 thermal, Uniphier MDMAC) enabled in defconfigs" * tag 'armsoc-late' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (27 commits) ARM: multi_v7_defconfig: enable CONFIG_UNIPHIER_MDMAC arm64: defconfig: Re-enable bcm2835-thermal driver MAINTAINERS: Add entry for RDA Micro SoC architecture tty: serial: Add RDA8810PL UART driver ARM: dts: rda8810pl: Add interrupt support for UART dt-bindings: serial: Document RDA Micro UART ARM: dts: rda8810pl: Add timer support ARM: dts: Add devicetree for OrangePi i96 board ARM: dts: Add devicetree for OrangePi 2G IoT board ARM: dts: Add devicetree for RDA8810PL SoC ARM: Prepare RDA8810PL SoC dt-bindings: arm: Document RDA8810PL and reference boards dt-bindings: Add RDA Micro vendor prefix ARM: sti: remove pen_release and boot_lock arm64: dts: exynos: Add Bluetooth chip to TM2(e) boards arm64: dts: imx8mq-evk: enable watchdog arm64: dts: imx8mq: add watchdog devices MAINTAINERS: add i.MX8 DT path to i.MX architecture arm64: add support for i.MX8M EVK board arm64: add basic DTS for i.MX8MQ ...
2018-12-31tty: serial: Add RDA8810PL UART driverManivannan Sadhasivam
Add UART driver for RDA Micro RDA8810PL SoC. Signed-off-by: Andreas Färber <afaerber@suse.de> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Olof Johansson <olof@lixom.net>
2018-12-28Merge tag 'tty-4.21-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial driver updates from Greg KH: "Here is the large TTY/Serial driver set of patches for 4.21-rc1. A number of small serial driver changes along with some good tty core fixes for long-reported issues with locking. There is also a new console font added to the tree, for high-res screens, so that should be helpful for many. The last patch in the series is a revert of an older one in the tree, it came late but it resolves a reported issue that linux-next was having for some people. Full details are in the shortlog, and all of these, with the exception of the revert, have been in linux-next for a while with no reported issues" * tag 'tty-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (85 commits) Revert "serial: 8250: Default SERIAL_OF_PLATFORM to SERIAL_8250" serial: sccnxp: Allow to use non-standard baud rates serial: sccnxp: Adds a delay between sequential read/write cycles tty: serial: qcom_geni_serial: Fix UART hang tty: serial: qcom_geni_serial: Fix wrap around of TX buffer serial: max310x: Fix tx_empty() callback dt-bindings: serial: sh-sci: Document r8a774c0 bindings dt-bindings: serial: sh-sci: Document r8a774a1 bindings Fonts: New Terminus large console font dt-bindings: serial: lpuart: add imx8qxp compatible string serial: uartps: Fix interrupt mask issue to handle the RX interrupts properly serial: uartps: Fix error path when alloc failed serial: uartps: Check if the device is a console serial: uartps: Add the device_init_wakeup tty: serial: samsung: Increase maximum baudrate tty: serial: samsung: Properly set flags in autoCTS mode tty: Use of_node_name_{eq,prefix} for node name comparisons tty/serial: do not free trasnmit buffer page under port lock serial: 8250: Rate limit serial port rx interrupts during input overruns dt-bindings: serial: 8250: Add rate limit for serial port input overruns ...
2018-12-24Revert "serial: 8250: Default SERIAL_OF_PLATFORM to SERIAL_8250"Greg Kroah-Hartman
This reverts commit 6d11023c345e369bcb9d5a68b271764e362c1f6e. It causes issues with Guenter's test systems and since there seems to not be any agreement about _why_ this is a problem, but reverting it fixes things, let's revert until the root cause is found. Reported-by: Guenter Roeck <linux@roeck-us.net> Cc: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparcLinus Torvalds
Pull sparc fixes from David Miller: "Just some small fixes here and there, and a refcount leak in a serial driver, nothing serious" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc: serial/sunsu: fix refcount leak sparc: Set "ARCH: sunxx" information on the same line sparc: vdso: Drop implicit common-page-size linker flag
2018-12-21serial/sunsu: fix refcount leakYangtao Li
The function of_find_node_by_path() acquires a reference to the node returned by it and that reference needs to be dropped by its caller. su_get_type() doesn't do that. The match node are used as an identifier to compare against the current node, so we can directly drop the refcount after getting the node from the path as it is not used as pointer. Fix this by use a single variable and drop the refcount right after of_find_node_by_path(). Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-20serial: sccnxp: Allow to use non-standard baud ratesAlexander Shiyan
This patch adds support for the use of non-standard baud rates. For these purposes, we use the built-in timer/counter. Signed-off-by: Alexander Shiyan <shc_work@mail.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-20serial: sccnxp: Adds a delay between sequential read/write cyclesAlexander Shiyan
This patch adds a delay between sequential read/write cycles, to ensure the required minimum inactive time (tRWD). A time value from the datasheet has been added for each type of supported chips. The “inline” compiler attribute has been removed from the read/write functions, simply allow the compiler to control this. Signed-off-by: Alexander Shiyan <shc_work@mail.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-20tty: serial: qcom_geni_serial: Fix UART hangRyan Case
If a serial console write occured while a UART transmit command was waiting for a done signal then no further data would be sent until something new kicked the system into gear. If there is already data waiting in the circular buffer we must re-enable the tx watermark so we receive the expected interrupts. Signed-off-by: Ryan Case <ryandcase@chromium.org> Reviewed-by: Evan Green <evgreen@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-20tty: serial: qcom_geni_serial: Fix wrap around of TX bufferMatthias Kaehlcke
Before commit a1fee899e5bed ("tty: serial: qcom_geni_serial: Fix softlock") the size of TX transfers was limited to the TX FIFO size, and wrap arounds of the UART circular buffer were split into two transfers. With the commit wrap around are allowed within a transfer. The TX FIFO of the geni serial port uses a word size of 4 bytes. In case of a circular buffer wrap within a transfer the driver currently may write an incomplete word to the FIFO, with some bytes containing data from the circular buffer and others being zero. Since the transfer isn't completed yet the zero bytes are sent as if they were actual data. Handle wrap arounds of the TX buffer properly and ensure that words written to the TX FIFO always contain valid data (unless the transfer is completed). Fixes: a1fee899e5bed ("tty: serial: qcom_geni_serial: Fix softlock") Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Reviewed-by: Evan Green <evgreen@chromium.org> Tested-by: Ryan Case <ryandcase@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-19serial: max310x: Fix tx_empty() callbackAlexander Shiyan
Function max310x_tx_empty() accesses the IRQSTS register, which is cleared by IC when reading, so if there is an interrupt status, we will lose it. This patch implement the transmitter check only by the current FIFO level. Signed-off-by: Alexander Shiyan <shc_work@mail.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-19serial: uartps: Fix interrupt mask issue to handle the RX interrupts properlyNava kishore Manne
This patch Correct the RX interrupt mask value to handle the RX interrupts properly. Fixes: c8dbdc842d30 ("serial: xuartps: Rewrite the interrupt handling logic") Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-19serial: uartps: Fix error path when alloc failedMichal Simek
When cdns_uart_console allocation failed there is a need to also clear ID from ID list. Fixes: ae1cca3fa347 ("serial: uartps: Change uart ID port allocation") Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-19serial: uartps: Check if the device is a consoleShubhrajyoti Datta
While checking for console_suspend_enabled also check if the device is a console. Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-19serial: uartps: Add the device_init_wakeupShubhrajyoti Datta
Initialise the device wakeup. The device_init_wakeup is needed for the wakeup to work by default. Uart can be configured as the primary wakeup source so it is good to enable wakeup by default. The same functionality is enabled also by 8250_omap, atmel_serial, omap-serial and stm32-usart. Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-17Revert "serial: 8250: Fix clearing FIFOs in RS485 mode again"Paul Burton
Commit f6aa5beb45be ("serial: 8250: Fix clearing FIFOs in RS485 mode again") makes a change to FIFO clearing code which its commit message suggests was intended to be specific to use with RS485 mode, however: 1) The change made does not just affect __do_stop_tx_rs485(), it also affects other uses of serial8250_clear_fifos() including paths for starting up, shutting down or auto-configuring a port regardless of whether it's an RS485 port or not. 2) It makes the assumption that resetting the FIFOs is a no-op when FIFOs are disabled, and as such it checks for this case & explicitly avoids setting the FIFO reset bits when the FIFO enable bit is clear. A reading of the PC16550D manual would suggest that this is OK since the FIFO should automatically be reset if it is later enabled, but we support many 16550-compatible devices and have never required this auto-reset behaviour for at least the whole git era. Starting to rely on it now seems risky, offers no benefit, and indeed breaks at least the Ingenic JZ4780's UARTs which reads garbage when the RX FIFO is enabled if we don't explicitly reset it. 3) By only resetting the FIFOs if they're enabled, the behaviour of serial8250_do_startup() during boot now depends on what the value of FCR is before the 8250 driver is probed. This in itself seems questionable and leaves us with FCR=0 & no FIFO reset if the UART was used by 8250_early, otherwise it depends upon what the bootloader left behind. 4) Although the naming of serial8250_clear_fifos() may be unclear, it is clear that callers of it expect that it will disable FIFOs. Both serial8250_do_startup() & serial8250_do_shutdown() contain comments to that effect, and other callers explicitly re-enable the FIFOs after calling serial8250_clear_fifos(). The premise of that patch that disabling the FIFOs is incorrect therefore seems wrong. For these reasons, this reverts commit f6aa5beb45be ("serial: 8250: Fix clearing FIFOs in RS485 mode again"). Signed-off-by: Paul Burton <paul.burton@mips.com> Fixes: f6aa5beb45be ("serial: 8250: Fix clearing FIFOs in RS485 mode again"). Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Daniel Jedrychowski <avistel@gmail.com> Cc: Marek Vasut <marex@denx.de> Cc: linux-mips@vger.kernel.org Cc: linux-serial@vger.kernel.org Cc: stable <stable@vger.kernel.org> # 4.10+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-17tty: serial: samsung: Increase maximum baudrateSeung-Woo Kim
This driver can be used to communicate with Bluetooth chip in high-speed UART mode, so increase the maximum baudrate to 3Mbps. Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com> [mszyprow: rephrased commit message] Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-17tty: serial: samsung: Properly set flags in autoCTS modeBeomho Seo
Commit 391f93f2ec9f ("serial: core: Rework hw-assited flow control support") has changed the way the autoCTS mode is handled. According to that change, serial drivers which enable H/W autoCTS mode must set UPSTAT_AUTOCTS to prevent the serial core from inadvertently disabling TX. This patch adds proper handling of UPSTAT_AUTOCTS flag. Signed-off-by: Beomho Seo <beomho.seo@samsung.com> [mszyprow: rephrased commit message] Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-17tty: Use of_node_name_{eq,prefix} for node name comparisonsRob Herring
Convert string compares of DT node names to use of_node_name_eq helper instead. This removes direct access to the node name pointer. For hvc, the code can also be simplified by using of_stdout pointer instead of searching again for the stdout node. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-serial@vger.kernel.org Cc: sparclinux@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-17tty/serial: do not free trasnmit buffer page under port lockSergey Senozhatsky
LKP has hit yet another circular locking dependency between uart console drivers and debugobjects [1]: CPU0 CPU1 rhltable_init() __init_work() debug_object_init uart_shutdown() /* db->lock */ /* uart_port->lock */ debug_print_object() free_page() printk() call_console_drivers() debug_check_no_obj_freed() /* uart_port->lock */ /* db->lock */ debug_print_object() So there are two dependency chains: uart_port->lock -> db->lock And db->lock -> uart_port->lock This particular circular locking dependency can be addressed in several ways: a) One way would be to move debug_print_object() out of db->lock scope and, thus, break the db->lock -> uart_port->lock chain. b) Another one would be to free() transmit buffer page out of db->lock in UART code; which is what this patch does. It makes sense to apply a) and b) independently: there are too many things going on behind free(), none of which depend on uart_port->lock. The patch fixes transmit buffer page free() in uart_shutdown() and, additionally, in uart_port_startup() (as was suggested by Dmitry Safonov). [1] https://lore.kernel.org/lkml/20181211091154.GL23332@shao2-debian/T/#u Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Waiman Long <longman@redhat.com> Cc: Dmitry Safonov <dima@arista.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-17serial: 8250: Rate limit serial port rx interrupts during input overrunsDarwin Dingel
When a serial port gets faulty or gets flooded with inputs, its interrupt handler starts to work double time to get the characters to the workqueue for the tty layer to handle them. When this busy time on the serial/tty subsystem happens during boot, where it is also busy on the userspace trying to initialise, some processes can continuously get preempted and will be on hold until the interrupts subside. The fix is to backoff on processing received characters for a specified amount of time when an input overrun is seen (received a new character before the previous one is processed). This only stops receive and will continue to transmit characters to serial port. After the backoff period is done, it receive will be re-enabled. This is optional and will only be enabled by setting 'overrun-throttle-ms' in the dts. Signed-off-by: Darwin Dingel <darwin.dingel@alliedtelesis.co.nz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-17tty: serial: qcom_geni_serial: Remove interrupt stormRyan Case
Disable M_TX_FIFO_WATERMARK_EN after we've sent all data for a given transaction so we don't continue to receive a flurry of free space interrupts while waiting for the M_CMD_DONE notification. Re-enable the watermark when establishing the next transaction. Also clear the watermark interrupt after filling the FIFO so we do not receive notification again prior to actually having free space. Signed-off-by: Ryan Case <ryandcase@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Tested-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-17serial: sh-sci: Resume PIO in sci_rx_interrupt() on DMA failureGeert Uytterhoeven
On (H)SCIF, sci_submit_rx() is called in the receive interrupt handler. Hence if DMA submission fails, the interrupt handler should resume handling reception using PIO, else no more data is received. Make sci_submit_rx() return an error indicator, so the receive interrupt handler can act appropriately. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-17serial: sh-sci: Fix crash in rx_timer_fn() on PIO fallbackGeert Uytterhoeven
When falling back to PIO, active_rx must be set to a different value than cookie_rx[i], else sci_dma_rx_find_active() will incorrectly find a match, leading to a NULL pointer dereference in rx_timer_fn() later. Use zero instead, which is the same value as after driver initialization. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-17serial: sh-sci: Fix locking in sci_submit_rx()Geert Uytterhoeven
Some callers of sci_submit_rx() hold the port spinlock, others don't. During fallback to PIO, the driver needs to obtain the port spinlock. If the lock was already held, spinlock recursion is detected, causing a deadlock: BUG: spinlock recursion on CPU#0. Fix this by adding a flag parameter to sci_submit_rx() for the caller to indicate the port spinlock is already held, so spinlock recursion can be avoided. Move the spin_lock_irqsave() up, so all DMA disable steps are protected, which is safe as the recently introduced dmaengine_terminate_async() can be called in atomic context. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-10Merge 4.20-rc6 into tty-nextGreg Kroah-Hartman
We want the TTY changes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-09Merge tag 'tty-4.20-rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty driver fixes from Greg KH: "Here are three small tty driver fixes for 4.20-rc6 Nothing major, just some bug fixes for reported issues. Full details are in the shortlog. All of these have been in linux-next for a while with no reported issues" * tag 'tty-4.20-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: kgdboc: fix KASAN global-out-of-bounds bug in param_set_kgdboc_var() tty: serial: 8250_mtk: always resume the device in probe. tty: do not set TTY_IO_ERROR flag if console port
2018-12-06kgdboc: fix KASAN global-out-of-bounds bug in param_set_kgdboc_var()Macpaul Lin
This patch is trying to fix KE issue due to "BUG: KASAN: global-out-of-bounds in param_set_kgdboc_var+0x194/0x198" reported by Syzkaller scan." [26364:syz-executor0][name:report8t]BUG: KASAN: global-out-of-bounds in param_set_kgdboc_var+0x194/0x198 [26364:syz-executor0][name:report&]Read of size 1 at addr ffffff900e44f95f by task syz-executor0/26364 [26364:syz-executor0][name:report&] [26364:syz-executor0]CPU: 7 PID: 26364 Comm: syz-executor0 Tainted: G W 0 [26364:syz-executor0]Call trace: [26364:syz-executor0][<ffffff9008095cf8>] dump_bacIctrace+Ox0/0x470 [26364:syz-executor0][<ffffff9008096de0>] show_stack+0x20/0x30 [26364:syz-executor0][<ffffff90089cc9c8>] dump_stack+Oxd8/0x128 [26364:syz-executor0][<ffffff90084edb38>] print_address_description +0x80/0x4a8 [26364:syz-executor0][<ffffff90084ee270>] kasan_report+Ox178/0x390 [26364:syz-executor0][<ffffff90084ee4a0>] _asan_report_loadi_noabort+Ox18/0x20 [26364:syz-executor0][<ffffff9008b092ac>] param_set_kgdboc_var+Ox194/0x198 [26364:syz-executor0][<ffffff900813af64>] param_attr_store+Ox14c/0x270 [26364:syz-executor0][<ffffff90081394c8>] module_attr_store+0x60/0x90 [26364:syz-executor0][<ffffff90086690c0>] sysfs_kl_write+Ox100/0x158 [26364:syz-executor0][<ffffff9008666d84>] kernfs_fop_write+0x27c/0x3a8 [26364:syz-executor0][<ffffff9008508264>] do_loop_readv_writev+0x114/0x1b0 [26364:syz-executor0][<ffffff9008509ac8>] do_readv_writev+0x4f8/0x5e0 [26364:syz-executor0][<ffffff9008509ce4>] vfs_writev+0x7c/Oxb8 [26364:syz-executor0][<ffffff900850ba64>] SyS_writev+Oxcc/0x208 [26364:syz-executor0][<ffffff90080883f0>] elO_svc_naked +0x24/0x28 [26364:syz-executor0][name:report&] [26364:syz-executor0][name:report&]The buggy address belongs to the variable: [26364:syz-executor0][name:report&] kgdb_tty_line+Ox3f/0x40 [26364:syz-executor0][name:report&] [26364:syz-executor0][name:report&]Memory state around the buggy address: [26364:syz-executor0] ffffff900e44f800: 00 00 00 00 00 04 fa fa fa fa fa fa 00 fa fa fa [26364:syz-executor0] ffffff900e44f880: fa fa fa fa 00 fa fa fa fa fa fa fa 00 fa fa fa [26364:syz-executor0]> ffffff900e44f900: fa fa fa fa 04 fa fa fa fa fa fa fa 00 00 00 00 [26364:syz-executor0][name:report&] ^ [26364:syz-executor0] ffffff900e44f980: 00 fa fa fa fa fa fa fa 04 fa fa fa fa fa fa fa [26364:syz-executor0] ffffff900e44fa00: 04 fa fa fa fa fa fa fa 00 fa fa fa fa fa fa fa [26364:syz-executor0][name:report&] [26364:syz-executor0][name:panic&]Disabling lock debugging due to kernel taint [26364:syz-executor0]------------[cut here]------------ After checking the source code, we've found there might be an out-of-bounds access to "config[len - 1]" array when the variable "len" is zero. Signed-off-by: Macpaul Lin <macpaul@gmail.com> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-06Revert "tty: xilinx_uartps: Correct return value in probe"Greg Kroah-Hartman
This reverts commit eca42d4cf3c591c36312c52707e0a712e0c7256a. During review it was rejected, so drop it from the tree. Cc: Rajan Vaja <RAJANV@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-05tty: serial: 8250_mtk: always resume the device in probe.Peter Shih
serial8250_register_8250_port calls uart_config_port, which calls config_port on the port before it tries to power on the port. So we need the port to be on before calling serial8250_register_8250_port. Change the code to always do a runtime resume in probe before registering port, and always do a runtime suspend in remove. This basically reverts the change in commit 68e5fc4a255a ("tty: serial: 8250_mtk: use pm_runtime callbacks for enabling"), but still use pm_runtime callbacks. Fixes: 68e5fc4a255a ("tty: serial: 8250_mtk: use pm_runtime callbacks for enabling") Signed-off-by: Peter Shih <pihsun@chromium.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-05serial: 8250-mtk: add uart DMA supportLong Cheng
Modify uart register to support DMA function. Signed-off-by: Long Cheng <long.cheng@mediatek.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-05tty: xilinx_uartps: Correct return value in probeRajan Vaja
Existing driver checks for alternate clock if devm_clk_get() fails and returns error code for last clock failure. If xilinx_uartps is called before clock driver, devm_clk_get() returns -EPROBE_DEFER. In this case, probe should not check for alternate clock as main clock is already present in DTS and return -EPROBE_DEFER only. This patch fixes it by not checking for alternate clock when main clock get returns -EPROBE_DEFER. Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-05tty: serial: qcom_geni_serial: Fix softlockRyan Case
Transfers were being divided into device FIFO sized (64 byte max) operations which would poll for completion within a spin_lock_irqsave / spin_unlock_irqrestore block. This both made things slow by waiting for the FIFO to completely drain before adding further data and would also result in softlocks on large transmissions. This patch allows larger transfers with continuous FIFO additions as space becomes available and removes polling from the interrupt handler. Signed-off-by: Ryan Case <ryandcase@chromium.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-05Revert "serial/sunsu: add missing of_node_put()"Greg Kroah-Hartman
This reverts commit 20d8e8611eb0596047fd4389be7a7203a883b9bf. As David Miller points out, it's wrong. Reported-by: David Miller <davem@davemloft.net> Cc: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-02drivers/tty: add missing of_node_put()Yangtao Li
of_find_node_by_path() acquires a reference to the node returned by it and that reference needs to be dropped by its caller. This place is not doing this, so fix it. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-27serial: imx: fix error handling in console_setupStefan Agner
The ipg clock only needs to be unprepared in case preparing per clock fails. The ipg clock has already disabled at the point. Fixes: 1cf93e0d5488 ("serial: imx: remove the uart_console() check") Signed-off-by: Stefan Agner <stefan@agner.ch> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-27serial: mvebu-uart: initialize over sampling stack registerMiquel Raynal
The baudrate derivation relies on the state of the programmable over sampling stack (OSAMP register) being empty, while never initializing it. Set all the fields of this register to 0 (except reserved areas) to ensure a x16 divisor, as assumed by the driver. The suspend/resume callbacks are untouched because they already save/restore correctly this register. Suggested-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-27serial: mvebu-uart: clarify the baud rate derivationMiquel Raynal
The current comment in ->set_baud_rate() is rather incomplete as it fails to describe what are the actual stages for the baudrate derivation. Replace this comment with something more explicit and close to the functional specification. Also adapt the variable names to it. Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-27serial/sunsu: add missing of_node_put()Yangtao Li
of_find_node_by_path() acquires a reference to the node returned by it and that reference needs to be dropped by its caller. This place is not doing this, so fix it. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-27drivers/tty: add missing of_node_put()Yangtao Li
of_find_node_by_path() acquires a reference to the node returned by it and that reference needs to be dropped by its caller. This place is not doing this, so fix it. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-27serial-uartlite: fix null pointer dereference on pointer portColin Ian King
Pointer port is dereferenced on port->private_data when assigning pointer pdata before port is null checked, leading to a potential null pointer dereference. Fix this by assigning pdata after the null pointer check on port. Detected by CoverityScan, CID#1475434 ("Dereference before null check") Fixes: 3b209d253e7f ("serial-uartlite: Do not use static struct uart_driver out of probe()") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-11Merge 4.20-rc2 into tty-nextGreg Kroah-Hartman
We want the tty/serial fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-10Merge tag 'tty-4.20-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial fixes from Greg KH: "Here are some small tty fixes for 4.20-rc2 One of these missed the original 4.19-final release, I missed that I hadn't done a pull request for it as it was in linux-next and my branch for a long time, that's my fault. The others are small, fixing some reported issues and finally fixing the termios mess for alpha so that glibc has a chance to implement some missing functionality that has been pending for many years now. All of these have been in linux-next with no reported issues" * tag 'tty-4.20-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: serial: sh-sci: Fix could not remove dev_attr_rx_fifo_timeout arch/alpha, termios: implement BOTHER, IBSHIFT and termios2 termios, tty/tty_baudrate.c: fix buffer overrun vt: fix broken display when running aptitude serial: sh-sci: Fix receive on SCIFA/SCIFB variants with DMA