summaryrefslogtreecommitdiffstats
path: root/drivers/tty
AgeCommit message (Collapse)AuthorFilesLines
2019-07-19Merge tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/socLinus Torvalds2-4/+43
Pull ARM SoC platform updates from Olof Johansson: "SoC platform changes. Main theme this merge window: - The Netx platform (Netx 100/500) platform is removed by Linus Walleij-- the SoC doesn't have active maintainers with hardware, and in discussions with the vendor the agreement was that it's OK to remove. - Russell King has a series of patches that cleans up and refactors SA1101 and RiscPC support" * tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (47 commits) ARM: stm32: use "depends on" instead of "if" after prompt ARM: sa1100: convert to common clock framework ARM: exynos: Cleanup cppcheck shifting warning ARM: pxa/lubbock: remove lubbock_set_misc_wr() from global view ARM: exynos: Only build MCPM support if used arm: add missing include platform-data/atmel.h ARM: davinci: Use GPIO lookup table for DA850 LEDs ARM: OMAP2: drop explicit assembler architecture ARM: use arch_extension directive instead of arch argument ARM: imx: Switch imx7d to imx-cpufreq-dt for speed-grading ARM: bcm: Enable PINCTRL for ARCH_BRCMSTB ARM: bcm: Enable ARCH_HAS_RESET_CONTROLLER for ARCH_BRCMSTB ARM: riscpc: enable chained scatterlist support ARM: riscpc: reduce IRQ handling code ARM: riscpc: move RiscPC assembly files from arch/arm/lib to mach-rpc ARM: riscpc: parse video information from tagged list ARM: riscpc: add ecard quirk for Atomwide 3port serial card MAINTAINERS: mvebu: Add git entry soc: ti: pm33xx: Add a print while entering RTC only mode with DDR in self-refresh ARM: OMAP2+: Make some variables static ...
2019-07-18proc/sysctl: add shared variables for range checkMatteo Croce1-4/+2
In the sysctl code the proc_dointvec_minmax() function is often used to validate the user supplied value between an allowed range. This function uses the extra1 and extra2 members from struct ctl_table as minimum and maximum allowed value. On sysctl handler declaration, in every source file there are some readonly variables containing just an integer which address is assigned to the extra1 and extra2 members, so the sysctl range is enforced. The special values 0, 1 and INT_MAX are very often used as range boundary, leading duplication of variables like zero=0, one=1, int_max=INT_MAX in different source files: $ git grep -E '\.extra[12].*&(zero|one|int_max)' |wc -l 248 Add a const int array containing the most commonly used values, some macros to refer more easily to the correct array member, and use them instead of creating a local one for every object file. This is the bloat-o-meter output comparing the old and new binary compiled with the default Fedora config: # scripts/bloat-o-meter -d vmlinux.o.old vmlinux.o add/remove: 2/2 grow/shrink: 0/2 up/down: 24/-188 (-164) Data old new delta sysctl_vals - 12 +12 __kstrtab_sysctl_vals - 12 +12 max 14 10 -4 int_max 16 - -16 one 68 - -68 zero 128 28 -100 Total: Before=20583249, After=20583085, chg -0.00% [mcroce@redhat.com: tipc: remove two unused variables] Link: http://lkml.kernel.org/r/20190530091952.4108-1-mcroce@redhat.com [akpm@linux-foundation.org: fix net/ipv6/sysctl_net_ipv6.c] [arnd@arndb.de: proc/sysctl: make firmware loader table conditional] Link: http://lkml.kernel.org/r/20190617130014.1713870-1-arnd@arndb.de [akpm@linux-foundation.org: fix fs/eventpoll.c] Link: http://lkml.kernel.org/r/20190430180111.10688-1-mcroce@redhat.com Signed-off-by: Matteo Croce <mcroce@redhat.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Kees Cook <keescook@chromium.org> Reviewed-by: Aaron Tomlin <atomlin@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-15Merge branch 'for-arm-soc' of git://git.armlinux.org.uk/~rmk/linux-arm into ↵Olof Johansson2-4/+43
arm/soc * 'for-arm-soc' of git://git.armlinux.org.uk/~rmk/linux-arm: (21 commits) ARM: sa1100: convert to common clock framework ARM: riscpc: enable chained scatterlist support ARM: riscpc: reduce IRQ handling code ARM: riscpc: move RiscPC assembly files from arch/arm/lib to mach-rpc ARM: riscpc: parse video information from tagged list ARM: riscpc: add ecard quirk for Atomwide 3port serial card ARM: sa1100/neponset: convert serial to use gpiod APIs ARM: sa1100/hackkit: remove empty serial mctrl functions ARM: sa1100/badge4: remove commented out modem control initialisers ARM: sa1100/h3xxx: convert serial to gpiod APIs ARM: sa1100/assabet: convert serial to gpiod APIs serial: sa1100: add note about modem control signals serial: sa1100: add support for mctrl gpios ARM: riscpc: dma: use __iomem pointers for writing DMA ARM: riscpc: dma: improve address/length writing ARM: riscpc: dma: make state a local variable ARM: riscpc: dma: eliminate "cur_sg" scatterlist usage ARM: riscpc: fix DMA ARM: riscpc: fix ecard printing ARM: riscpc: fix lack of keyboard interrupts after irq conversion ... Signed-off-by: Olof Johansson <olof@lixom.net>
2019-07-15docs: serial: move it to the driver-apiMauro Carvalho Chehab2-3/+3
The contents of this directory is mostly driver-api stuff. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-15docs: driver-api: add a series of orphaned documentsMauro Carvalho Chehab1-1/+1
There are lots of documents under Documentation/*.txt and a few other orphan documents elsehwere that belong to the driver-API book. Move them to their right place. Reviewed-by: Cornelia Huck <cohuck@redhat.com> # vfio-related parts Acked-by: Logan Gunthorpe <logang@deltatee.com> # switchtec Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-15docs: arm: convert docs to ReST and rename to *.rstMauro Carvalho Chehab1-1/+1
Converts ARM the text files to ReST, preparing them to be an architecture book. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Reviewed-by Corentin Labbe <clabbe.montjoie@gmail.com> # For sun4i-ss
2019-07-15docs: console.txt: convert docs to ReST and rename to *.rstMauro Carvalho Chehab1-1/+1
Convert this small file to ReST in preparation for adding it to the driver-api book. While this is not part of the driver-api book, mark it as :orphan:, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
2019-07-13Merge tag 'powerpc-5.3-1' of ↵Linus Torvalds1-1/+15
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "Notable changes: - Removal of the NPU DMA code, used by the out-of-tree Nvidia driver, as well as some other functions only used by drivers that haven't (yet?) made it upstream. - A fix for a bug in our handling of hardware watchpoints (eg. perf record -e mem: ...) which could lead to register corruption and kernel crashes. - Enable HAVE_ARCH_HUGE_VMAP, which allows us to use large pages for vmalloc when using the Radix MMU. - A large but incremental rewrite of our exception handling code to use gas macros rather than multiple levels of nested CPP macros. And the usual small fixes, cleanups and improvements. Thanks to: Alastair D'Silva, Alexey Kardashevskiy, Andreas Schwab, Aneesh Kumar K.V, Anju T Sudhakar, Anton Blanchard, Arnd Bergmann, Athira Rajeev, Cédric Le Goater, Christian Lamparter, Christophe Leroy, Christophe Lombard, Christoph Hellwig, Daniel Axtens, Denis Efremov, Enrico Weigelt, Frederic Barrat, Gautham R. Shenoy, Geert Uytterhoeven, Geliang Tang, Gen Zhang, Greg Kroah-Hartman, Greg Kurz, Gustavo Romero, Krzysztof Kozlowski, Madhavan Srinivasan, Masahiro Yamada, Mathieu Malaterre, Michael Neuling, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Nishad Kamdar, Oliver O'Halloran, Qian Cai, Ravi Bangoria, Sachin Sant, Sam Bobroff, Satheesh Rajendran, Segher Boessenkool, Shaokun Zhang, Shawn Anastasio, Stewart Smith, Suraj Jitindar Singh, Thiago Jung Bauermann, YueHaibing" * tag 'powerpc-5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (163 commits) powerpc/powernv/idle: Fix restore of SPRN_LDBAR for POWER9 stop state. powerpc/eeh: Handle hugepages in ioremap space ocxl: Update for AFU descriptor template version 1.1 powerpc/boot: pass CONFIG options in a simpler and more robust way powerpc/boot: add {get, put}_unaligned_be32 to xz_config.h powerpc/irq: Don't WARN continuously in arch_local_irq_restore() powerpc/module64: Use symbolic instructions names. powerpc/module32: Use symbolic instructions names. powerpc: Move PPC_HA() PPC_HI() and PPC_LO() to ppc-opcode.h powerpc/module64: Fix comment in R_PPC64_ENTRY handling powerpc/boot: Add lzo support for uImage powerpc/boot: Add lzma support for uImage powerpc/boot: don't force gzipped uImage powerpc/8xx: Add microcode patch to move SMC parameter RAM. powerpc/8xx: Use IO accessors in microcode programming. powerpc/8xx: replace #ifdefs by IS_ENABLED() in microcode.c powerpc/8xx: refactor programming of microcode CPM params. powerpc/8xx: refactor printing of microcode patch name. powerpc/8xx: Refactor microcode write powerpc/8xx: refactor writing of CPM microcode arrays ...
2019-07-13Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparcLinus Torvalds1-1/+1
Pull sparc updates from David Miller: "Just a few small changes: - Fix console naming inconsistency with hypervisor consoles, from John Paul Adrian Glaubitz - Fix userland compilation due to use of u_int, from Masahiro Yamada" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc: sparc64: Add missing newline at end of file sparc: fix unknown type name u_int in uapi header sparc: configs: Remove useless UEVENT_HELPER_PATH sparc: Remove redundant copy of the LGPL-2.0 sunhv: Fix device naming inconsistency between sunhv_console and sunhv_reg
2019-07-11Merge tag 'tty-5.3-rc1' of ↵Linus Torvalds27-2552/+864
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty / serial driver updates from Greg KH: "Here is the "large" TTY and Serial driver update for 5.3-rc1. It's in the negative number of lines overall as we removed an obsolete serial driver that was causing problems for some people who were trying to clean up some apis (the mpsc.c driver, which only worked for some pre-production hardware that no one has anymore.) Other than that, lots of tiny changes, cleaning up small things along with some platform-specific serial driver updates. All of these have been in linux-next for a while now with no reported issues" * tag 'tty-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (68 commits) tty: serial: fsl_lpuart: add imx8qxp support serial: imx: set_termios(): preserve RTS state serial: imx: set_termios(): clarify RTS/CTS bits calculation serial: imx: set_termios(): factor-out 'ucr2' initial value serial: sh-sci: Terminate TX DMA during buffer flushing serial: sh-sci: Fix TX DMA buffer flushing and workqueue races serial: mpsc: Remove obsolete MPSC driver serial: 8250: 8250_core: Fix missing unlock on error in serial8250_register_8250_port() serial: stm32: add RX and TX FIFO flush serial: stm32: add support of RX FIFO threshold serial: stm32: add support of TX FIFO threshold serial: stm32: update PIO transmission serial: stm32: add support of timeout interrupt for RX Revert "serial: 8250: Don't service RX FIFO if interrupts are disabled" tty/serial/8250: use mctrl_gpio helpers serial: mctrl_gpio: Check if GPIO property exisits before requesting it serial: 8250: pericom_do_set_divisor can be static tty: serial_core: Set port active bit in uart_port_activate serial: 8250: Add MSR/MCR TIOCM conversion wrapper functions serial: 8250: factor out serial8250_{set,clear}_THRI() helpers ...
2019-07-09Merge tag 'docs-5.3' of git://git.lwn.net/linuxLinus Torvalds1-1/+1
Pull Documentation updates from Jonathan Corbet: "It's been a relatively busy cycle for docs: - A fair pile of RST conversions, many from Mauro. These create more than the usual number of simple but annoying merge conflicts with other trees, unfortunately. He has a lot more of these waiting on the wings that, I think, will go to you directly later on. - A new document on how to use merges and rebases in kernel repos, and one on Spectre vulnerabilities. - Various improvements to the build system, including automatic markup of function() references because some people, for reasons I will never understand, were of the opinion that :c:func:``function()`` is unattractive and not fun to type. - We now recommend using sphinx 1.7, but still support back to 1.4. - Lots of smaller improvements, warning fixes, typo fixes, etc" * tag 'docs-5.3' of git://git.lwn.net/linux: (129 commits) docs: automarkup.py: ignore exceptions when seeking for xrefs docs: Move binderfs to admin-guide Disable Sphinx SmartyPants in HTML output doc: RCU callback locks need only _bh, not necessarily _irq docs: format kernel-parameters -- as code Doc : doc-guide : Fix a typo platform: x86: get rid of a non-existent document Add the RCU docs to the core-api manual Documentation: RCU: Add TOC tree hooks Documentation: RCU: Rename txt files to rst Documentation: RCU: Convert RCU UP systems to reST Documentation: RCU: Convert RCU linked list to reST Documentation: RCU: Convert RCU basic concepts to reST docs: filesystems: Remove uneeded .rst extension on toctables scripts/sphinx-pre-install: fix out-of-tree build docs: zh_CN: submitting-drivers.rst: Remove a duplicated Documentation/ Documentation: PGP: update for newer HW devices Documentation: Add section about CPU vulnerabilities for Spectre Documentation: platform: Delete x86-laptop-drivers.txt docs: Note that :c:func: should no longer be used ...
2019-07-09Merge tag 'fbdev-v5.3' of git://github.com/bzolnier/linuxLinus Torvalds1-0/+18
Pull fbdev updates from Bartlomiej Zolnierkiewicz: - remove fbdev notifier usage for fbcon (as prep work to clean up the fbcon locking), add locking checks in vt/console code and make assorted cleanups in fbdev and backlight code (Daniel Vetter) - add COMPILE_TEST support to atmel_lcdfb, da8xx-fb, gbefb, imxfb, pvr2fb and pxa168fb drivers (me) - fix DMA API abuse in au1200fb and jz4740_fb drivers (Christoph Hellwig) - add check for new BGRT status field rotation bits in efifb driver (Hans de Goede) - mark expected switch fall-throughs in s3c-fb driver (Gustavo A. R. Silva) - remove fbdev mxsfb driver in favour of the drm version (Fabio Estevam) - remove broken rfbi code from omap2fb driver (me) - misc fixes (Arnd Bergmann, Shobhit Kukreti, Wei Yongjun, me) - misc cleanups (Gustavo A. R. Silva, Colin Ian King, me) * tag 'fbdev-v5.3' of git://github.com/bzolnier/linux: (62 commits) video: fbdev: imxfb: fix a typo in imxfb_probe() video: fbdev: s3c-fb: Mark expected switch fall-throughs video: fbdev: s3c-fb: fix sparse warnings about using incorrect types video: fbdev: don't print error message on framebuffer_alloc() failure video: fbdev: intelfb: return -ENOMEM on framebuffer_alloc() failure video: fbdev: s3c-fb: return -ENOMEM on framebuffer_alloc() failure vga_switcheroo: Depend upon fbcon being built-in, if enabled video: fbdev: omap2: remove rfbi video: fbdev: atmel_lcdfb: remove redundant initialization to variable ret video: fbdev-MMP: Use struct_size() in devm_kzalloc() video: fbdev: controlfb: fix warnings about comparing pointer to 0 efifb: BGRT: Add check for new BGRT status field rotation bits jz4740_fb: fix DMA API abuse video: fbdev: pvr2fb: fix link error for pvr2fb_pci_exit video: fbdev: s3c-fb: add COMPILE_TEST support video: fbdev: imxfb: fix sparse warnings about using incorrect types video: fbdev: pvr2fb: fix build warning when compiling as module fbcon: Export fbcon_update_vcs backlight: simplify lcd notifier staging/olpc_dcon: Add drm conversion to TODO ...
2019-07-04tty: serial: fsl_lpuart: add imx8qxp supportFugang Duan1-20/+86
The lpuart of imx8ulp is basically the same as imx7ulp, but it has new feature support based on imx7ulp, like it can assert a DMA request on EOP(end-of-packet). imx8ulp lpuart use two clocks, one is ipg bus clock that is used to access registers, the other is baud clock that is used to transmit-receive data. Signed-off-by: Fugang Duan <fugang.duan@nxp.com> Link: https://lore.kernel.org/r/20190704134007.2316-1-fugang.duan@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-03serial: imx: set_termios(): preserve RTS stateSergey Organov1-5/+9
imx_set_termios() cleared RTS on every call, now fixed. Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de> Tested-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Sergey Organov <sorganov@gmail.com> Link: https://lore.kernel.org/r/1561558293-7683-5-git-send-email-sorganov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-03serial: imx: set_termios(): clarify RTS/CTS bits calculationSergey Organov1-24/+14
Avoid repeating the same code for rs485 twice. Make it obvious we clear CRTSCTS bit in termios->c_cflag whenever sport->have_rtscts is false. Make it obvious we clear UCR2_IRTS whenever CRTSCTS is set. Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de> Tested-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Sergey Organov <sorganov@gmail.com> Link: https://lore.kernel.org/r/1561558293-7683-4-git-send-email-sorganov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-03serial: imx: set_termios(): factor-out 'ucr2' initial valueSergey Organov1-3/+2
Set common bits in a separate statement to make initialization explicit and not repeat the common part. Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de> Tested-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Sergey Organov <sorganov@gmail.com> Reviewed-by: Uwe Kleine-Knig <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/1561558293-7683-3-git-send-email-sorganov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-03serial: sh-sci: Terminate TX DMA during buffer flushingGeert Uytterhoeven1-2/+9
While the .flush_buffer() callback clears sci_port.tx_dma_len since commit 1cf4a7efdc71cab8 ("serial: sh-sci: Fix race condition causing garbage during shutdown"), it does not terminate a transmit DMA operation that may be in progress. Fix this by terminating any pending DMA operations, and resetting the corresponding cookie. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Eugeniu Rosca <erosca@de.adit-jv.com> Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com> Link: https://lore.kernel.org/r/20190624123540.20629-3-geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-03serial: sh-sci: Fix TX DMA buffer flushing and workqueue racesGeert Uytterhoeven1-7/+15
When uart_flush_buffer() is called, the .flush_buffer() callback zeroes the tx_dma_len field. This may race with the work queue function handling transmit DMA requests: 1. If the buffer is flushed before the first DMA API call, dmaengine_prep_slave_single() may be called with a zero length, causing the DMA request to never complete, leading to messages like: rcar-dmac e7300000.dma-controller: Channel Address Error happen and, with debug enabled: sh-sci e6e88000.serial: sci_dma_tx_work_fn: ffff800639b55000: 0...0, cookie 126 and DMA timeouts. 2. If the buffer is flushed after the first DMA API call, but before the second, dma_sync_single_for_device() may be called with a zero length, causing the transmit data not to be flushed to RAM, and leading to stale data being output. Fix this by: 1. Letting sci_dma_tx_work_fn() return immediately if the transmit buffer is empty, 2. Extending the critical section to cover all DMA preparational work, so tx_dma_len stays consistent for all of it, 3. Using local copies of circ_buf.head and circ_buf.tail, to make sure they match the actual operation above. Reported-by: Eugeniu Rosca <erosca@de.adit-jv.com> Suggested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Eugeniu Rosca <erosca@de.adit-jv.com> Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com> Link: https://lore.kernel.org/r/20190624123540.20629-2-geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-03serial: mpsc: Remove obsolete MPSC driverMark Greer3-2153/+0
Support for the Marvell MV64x60 line of bridge chips that contained MPSC controllers has been removed and there are no other components that have that controller so remove its driver. Signed-off-by: Mark Greer <mgreer@animalcreek.com> Link: https://lore.kernel.org/r/20190626160553.28518-1-mgreer@animalcreek.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-03serial: 8250: 8250_core: Fix missing unlock on error in ↵Wei Yongjun1-2/+5
serial8250_register_8250_port() Add the missing unlock before return from function serial8250_register_8250_port() in the error handling case. Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Link: https://lore.kernel.org/r/20190703055908.141294-1-weiyongjun1@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-21serial: stm32: add RX and TX FIFO flushErwan Le Ray1-5/+15
Adds a flush of RX and TX FIFOs, and fixes some errors: - adds RX FIFO flush in startup fonction - removes the useless transmitter enabling in startup fonction (e.g. receiver only, see Documentation/serial/driver) - configures FIFO threshold before enabling it, rather than after - flushes both TX and RX in set_termios function Signed-off-by: Erwan Le Ray <erwan.leray@st.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-21serial: stm32: add support of RX FIFO thresholdErwan Le Ray2-3/+25
Adds the support of RX FIFO threshold in order to improve the RX FIFO management. This is done by enabling fifo threshold interrupt, instead of relying on rx empty/fifo not full irq. That basically generates one irq/char currently. With this patch: - RXCFG is set to half fifo size (e.g. 16/2 = 8 data for a 16 data depth FIFO) - irq rate may be reduced by up to 1/RXCFG, e.g. 1 over 8 with current RXCFG setting. - Receiver timeout is used to gather chars when FIFO threshold isn't reached. Signed-off-by: Erwan Le Ray <erwan.leray@st.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-21serial: stm32: add support of TX FIFO thresholdErwan Le Ray2-9/+55
Adds the support of TX FIFO threshold in order to improve the TX FIFO management: - TX FIFO threshold irq enabling (instead of relying on tx empty / fifo not full irq that generates one irq/char) - TXCFG is set to half fifo size (e.g. 16/2 = 8 data for a 16 data depth FIFO) - irq rate may be reduced by up to 1/TXCFG, e.g. 1 over 8 with current TXCFG setting. Signed-off-by: Erwan Le Ray <erwan.leray@st.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-21serial: stm32: update PIO transmissionErwan Le Ray1-14/+13
Improves PIO transmission: - Replaces the FIFO filling per character by a filling per blocks of characters, which provides better performances - Replaces the active waiting loop by TX empty interrupt dynamic handling. TXE interrupt is now enabled when data has to be sent (ie when uart_circ is not empty), and inhibited when there is no more data to send (ie when uart_circ is empty). Signed-off-by: Erwan Le Ray <erwan.leray@st.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-21serial: stm32: add support of timeout interrupt for RXErwan Le Ray2-6/+26
Add support of RX timeout interrupts to limit the number of interrupts. RX timeout is a number of bits (baud clock cycles) without transmission seen in the receiver. One character is used as an arbitrary RX timeout value. If parity is enabled, the number of bits has to include parity bit. Signed-off-by: Gerald Baeza <gerald.baeza@st.com> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Signed-off-by: Erwan Le Ray <erwan.leray@st.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-21Revert "serial: 8250: Don't service RX FIFO if interrupts are disabled"Oliver Barta1-2/+1
This reverts commit 2e9fe539108320820016f78ca7704a7342788380. Reading LSR unconditionally but processing the error flags only if UART_IIR_RDI bit was set before in IIR may lead to a loss of transmission error information on UARTs where the transmission error flags are cleared by a read of LSR. Information are lost in case an error is detected right before the read of LSR while processing e.g. an UART_IIR_THRI interrupt. Signed-off-by: Oliver Barta <o.barta89@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Fixes: 2e9fe5391083 ("serial: 8250: Don't service RX FIFO if interrupts are disabled") Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-21tty/serial/8250: use mctrl_gpio helpersYegor Yefremov5-15/+61
This patch permits the usage for GPIOs to control the CTS/RTS/DTR/DSR/DCD/RI signals. Changed by Stefan: Only call mctrl_gpio_init(), if the device has no ACPI companion device to not break existing ACPI based systems. Also only use the mctrl_gpio_ functions when "gpios" is available. Use MSR / MCR <-> TIOCM wrapper functions. Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com> Signed-off-by: Stefan Roese <sr@denx.de> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Tested-by: Yegor Yefremov <yegorslists@googlemail.com> Cc: Mika Westerberg <mika.westerberg@linux.intel.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Giulio Benetti <giulio.benetti@micronovasrl.com> Cc: Yegor Yefremov <yegorslists@googlemail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-21serial: mctrl_gpio: Check if GPIO property exisits before requesting itStefan Roese1-0/+14
This patch adds a check for the GPIOs property existence, before the GPIO is requested. This fixes an issue seen when the 8250 mctrl_gpio support is added (2nd patch in this patch series) on x86 platforms using ACPI. Here Mika's comments from 2016-08-09: " I noticed that with v4.8-rc1 serial console of some of our Broxton systems does not work properly anymore. I'm able to see output but input does not work. I bisected it down to commit 4ef03d328769eddbfeca1f1c958fdb181a69c341 ("tty/serial/8250: use mctrl_gpio helpers"). The reason why it fails is that in ACPI we do not have names for GPIOs (except when _DSD is used) so we use the "idx" to index into _CRS GPIO resources. Now mctrl_gpio_init_noauto() goes through a list of GPIOs calling devm_gpiod_get_index_optional() passing "idx" of 0 for each. The UART device in Broxton has following (simplified) ACPI description: Device (URT4) { ... Name (_CRS, ResourceTemplate () { GpioIo (Exclusive, PullDefault, 0x0000, 0x0000, IoRestrictionOutputOnly, "\\_SB.GPO0", 0x00, ResourceConsumer) { 0x003A } GpioIo (Exclusive, PullDefault, 0x0000, 0x0000, IoRestrictionOutputOnly, "\\_SB.GPO0", 0x00, ResourceConsumer) { 0x003D } }) In this case it finds the first GPIO (0x003A which happens to be RX pin for that UART), turns it into GPIO which then breaks input for the UART device. This also breaks systems with bluetooth connected to UART (those typically have some GPIOs in their _CRS). Any ideas how to fix this? We cannot just drop the _CRS index lookup fallback because that would break many existing machines out there so maybe we can limit this to only DT enabled machines. Or alternatively probe if the property first exists before trying to acquire the GPIOs (using device_property_present()). " This patch implements the fix suggested by Mika in his statement above. Signed-off-by: Stefan Roese <sr@denx.de> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Tested-by: Yegor Yefremov <yegorslists@googlemail.com> Cc: Mika Westerberg <mika.westerberg@linux.intel.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Yegor Yefremov <yegorslists@googlemail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Giulio Benetti <giulio.benetti@micronovasrl.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18serial: 8250: pericom_do_set_divisor can be statickbuild test robot1-1/+1
Fixes: 6bf4e42f1d19 ("serial: 8250: Add support for higher baud rates to Pericom chips") Signed-off-by: kbuild test robot <lkp@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18tty: serial_core: Set port active bit in uart_port_activateSerge Semin1-1/+6
A bug was introduced by commit b3b576461864 ("tty: serial_core: convert uart_open to use tty_port_open"). It caused a constant warning printed into the system log regarding the tty and port counter mismatch: [ 21.644197] ttyS ttySx: tty_port_close_start: tty->count = 1 port count = 2 in case if session hangup was detected so the warning is printed starting from the second open-close iteration. Particularly the problem was discovered in situation when there is a serial tty device without hardware back-end being setup. It is considered by the tty-serial subsystems as a hardware problem with session hang up. In this case uart_startup() will return a positive value with TTY_IO_ERROR flag set in corresponding tty_struct instance. The same value will get passed to be returned from the activate() callback and then being returned from tty_port_open(). But since in this case tty_port_block_til_ready() isn't called the TTY_PORT_ACTIVE flag isn't set (while the method had been called before tty_port_open conversion was introduced and the rest of the subsystem code expected the bit being set in this case), which prevents the uart_hangup() method to perform any cleanups including the tty port counter setting to zero. So the next attempt to open/close the tty device will discover the counters mismatch. In order to fix the problem we need to manually set the TTY_PORT_ACTIVE flag in case if uart_startup() returned a positive value. In this case the hang up procedure will perform a full set of cleanup actions including the port ref-counter resetting. Fixes: b3b576461864 "tty: serial_core: convert uart_open to use tty_port_open" Signed-off-by: Serge Semin <fancer.lancer@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18serial: 8250: Add MSR/MCR TIOCM conversion wrapper functionsStefan Roese2-22/+57
This patch adds wrapper functions to convert MSR <-> TIOCM and also MCR <-> TIOCM. These functions are used now in serial8250_do_set_mctrl() and serial8250_do_get_mctrl(). Signed-off-by: Stefan Roese <sr@denx.de> Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Yegor Yefremov <yegorslists@googlemail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Giulio Benetti <giulio.benetti@micronovasrl.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18serial: 8250: factor out serial8250_{set,clear}_THRI() helpersAndy Shevchenko4-27/+26
Factor out similar code pieces that set or clear UART_IER_THRI bit to serial8250_{set,clear}_THRI() helpers. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18serial: fsl_lpuart: Remove unneeded OOM error messageFabio Estevam1-3/+1
There is no need to add an out-of-memory error message inside the driver because the core MM code will take care of it. Remove the unneeded OOM error message. Signed-off-by: Fabio Estevam <festevam@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18serial: uartps: Remove useless return from cdns_uart_poll_put_charNava kishore Manne1-2/+0
There is no reason to call return at the end of function which should return void. The patch is also remove one checkpatch warning: WARNING: void function return statements are not generally useful + return; +} Fixes: 6ee04c6c5488 ("tty: xuartps: Add polled mode support for xuartps") Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18serial: uartps: Do not add a trailing semicolon to macroNava kishore Manne1-1/+1
This patch fixes this checkpatch warning: WARNING: macros should not use a trailing semicolon +#define to_cdns_uart(_nb) container_of(_nb, struct cdns_uart, \ + clk_rate_change_nb); Fixes: d9bb3fb12685 ("tty: xuartps: Rebrand driver as Cadence UART") Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18serial: uartps: Fix long line over 80 charsNava kishore Manne1-1/+2
Trivial patch which fixes one checkpatch warning: WARNING: line over 80 characters + !(readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXFULL)) { Fixes: c8dbdc842d30 ("serial: xuartps: Rewrite the interrupt handling logic") Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18serial: uartps: Fix multiple line dereferenceNava kishore Manne1-2/+2
Trivial patch which fixes this checkpatch warning: WARNING: Avoid multiple line dereference - prefer 'port->state->xmit.tail' + port->state->xmit.buf[port->state->xmit. + tail], port->membase + CDNS_UART_FIFO); Fixes: c8dbdc842d30 ("serial: xuartps: Rewrite the interrupt handling logic") Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18serial: uartps: Use octal permission for module_param()Nava kishore Manne1-2/+2
Octal permission is preffered compare to symbolic one. This patch fixes checkpatch warnings: Symbolic permissions 'S_IRUGO' are not preferred. Consider using octal permissions '0444'. Fixes: 85baf542d54e ("tty: xuartps: support 64 byte FIFO size") Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18serial: uartps: Use the same dynamic major number for all portsShubhrajyoti Datta1-2/+3
Let kernel to find out major number dynamically for the first device and then reuse it for other instances. This fixes the issue that each uart is registered with a different major number. After the patch: crw------- 1 root root 253, 0 Jun 10 08:31 /dev/ttyPS0 crw--w---- 1 root root 253, 1 Jan 1 1970 /dev/ttyPS1 Fixes: 024ca329bfb9 ("serial: uartps: Register own uart console and driver structures") 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>
2019-06-18serial: 8250: Add support for higher baud rates to Pericom chipsJay Dolan1-18/+79
The Pericom chips can achieve additional baud rates by programming the sample clock register. The baud rates can be described as 921600 * 16 / (16 - scr) for scr values 5 to 15. The divisor is set to 1 for these baud rates. Adds new quirk for Pericom chips other than the four port chips to use the Signed-off-by: Jay Dolan <jay.dolan@accesio.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18serial: imx: fix locking in set_termios()Sergey Organov1-10/+13
imx_uart_set_termios() called imx_uart_rts_active(), or imx_uart_rts_inactive() before taking port->port.lock. As a consequence, sport->port.mctrl that these functions modify could have been changed without holding port->port.lock. Moved locking of port->port.lock above the calls to fix the issue. Signed-off-by: Sergey Organov <sorganov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-17locking/lockdep: Rename lockdep_assert_held_exclusive() -> ↵Nikolay Borisov1-4/+4
lockdep_assert_held_write() All callers of lockdep_assert_held_exclusive() use it to verify the correct locking state of either a semaphore (ldisc_sem in tty, mmap_sem for perf events, i_rwsem of inode for dax) or rwlock by apparmor. Thus it makes sense to rename _exclusive to _write since that's the semantics callers care. Additionally there is already lockdep_assert_held_read(), which this new naming is more consistent with. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190531100651.3969-1-nborisov@suse.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-14docs: fb: convert docs to ReST and rename to *.rstMauro Carvalho Chehab1-1/+1
The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Also, removed the Maintained by, as requested by Geert. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-14powerpc/pseries/hvconsole: Fix stack overread via udbgDaniel Axtens1-1/+15
While developing KASAN for 64-bit book3s, I hit the following stack over-read. It occurs because the hypercall to put characters onto the terminal takes 2 longs (128 bits/16 bytes) of characters at a time, and so hvc_put_chars() would unconditionally copy 16 bytes from the argument buffer, regardless of supplied length. However, udbg_hvc_putc() can call hvc_put_chars() with a single-byte buffer, leading to the error. ================================================================== BUG: KASAN: stack-out-of-bounds in hvc_put_chars+0xdc/0x110 Read of size 8 at addr c0000000023e7a90 by task swapper/0 CPU: 0 PID: 0 Comm: swapper Not tainted 5.2.0-rc2-next-20190528-02824-g048a6ab4835b #113 Call Trace: dump_stack+0x104/0x154 (unreliable) print_address_description+0xa0/0x30c __kasan_report+0x20c/0x224 kasan_report+0x18/0x30 __asan_report_load8_noabort+0x24/0x40 hvc_put_chars+0xdc/0x110 hvterm_raw_put_chars+0x9c/0x110 udbg_hvc_putc+0x154/0x200 udbg_write+0xf0/0x240 console_unlock+0x868/0xd30 register_console+0x970/0xe90 register_early_udbg_console+0xf8/0x114 setup_arch+0x108/0x790 start_kernel+0x104/0x784 start_here_common+0x1c/0x534 Memory state around the buggy address: c0000000023e7980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 c0000000023e7a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 >c0000000023e7a80: f1 f1 01 f2 f2 f2 00 00 00 00 00 00 00 00 00 00 ^ c0000000023e7b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 c0000000023e7b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== Document that a 16-byte buffer is requred, and provide it in udbg. Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-13sunhv: Fix device naming inconsistency between sunhv_console and sunhv_regJohn Paul Adrian Glaubitz1-1/+1
In d5a2aa24, the name in struct console sunhv_console was changed from "ttyS" to "ttyHV" while the name in struct uart_ops sunhv_pops remained unchanged. This results in the hypervisor console device to be listed as "ttyHV0" under /proc/consoles while the device node is still named "ttyS0": root@osaka:~# cat /proc/consoles ttyHV0 -W- (EC p ) 4:64 tty0 -WU (E ) 4:1 root@osaka:~# readlink /sys/dev/char/4:64 ../../devices/root/f02836f0/f0285690/tty/ttyS0 root@osaka:~# This means that any userland code which tries to determine the name of the device file of the hypervisor console device can not rely on the information provided by /proc/consoles. In particular, booting current versions of debian- installer inside a SPARC LDOM will fail with the installer unable to determine the console device. After renaming the device in struct uart_ops sunhv_pops to "ttyHV" as well, the inconsistency is fixed and it is possible again to determine the name of the device file of the hypervisor console device by reading the contents of /proc/console: root@osaka:~# cat /proc/consoles ttyHV0 -W- (EC p ) 4:64 tty0 -WU (E ) 4:1 root@osaka:~# readlink /sys/dev/char/4:64 ../../devices/root/f02836f0/f0285690/tty/ttyHV0 root@osaka:~# With this change, debian-installer works correctly when installing inside a SPARC LDOM. Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-13Revert "serial: stm32: select pinctrl state in each suspend/resume function"Greg Kroah-Hartman1-4/+0
This reverts commit c70669ecef4e34af8913108fae4b8a9b1dc63fa1 as it breaks the build. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Reported-by: kbuild test robot <lkp@intel.com> Cc: Bich Hemon <bich.hemon@st.com> Cc: Erwan Le Ray <erwan.leray@st.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-12vt: More locking checksDaniel Vetter1-0/+16
I honestly have no idea what the subtle differences between con_is_visible, con_is_fg (internal to vt.c) and con_is_bound are. But it looks like both vc->vc_display_fg and con_driver_map are protected by the console_lock, so probably better if we hold that when checking this. To do that I had to deinline the con_is_visible function. Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Reviewed-by: Sam Ravnborg <sam@ravnborg.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Martin Hostettler <textshell@uchuujin.de> Cc: Adam Borowski <kilobyte@angband.pl> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Mikulas Patocka <mpatocka@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190528090304.9388-5-daniel.vetter@ffwll.ch
2019-06-12vt: might_sleep() annotation for do_blank_screenDaniel Vetter1-0/+2
For symmetry reasons with do_unblank_screen, except without the oops_in_progress special case. Just a drive-by annotation while I'm trying to untangle the fbcon vs. fbdev screen blank/unblank maze. Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Reviewed-by: Sam Ravnborg <sam@ravnborg.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Adam Borowski <kilobyte@angband.pl> Cc: Martin Hostettler <textshell@uchuujin.de> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Mikulas Patocka <mpatocka@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190528090304.9388-4-daniel.vetter@ffwll.ch
2019-06-10tty: serial: msm_serial: avoid system lockup conditionJorge Ramirez-Ortiz1-0/+4
The function msm_wait_for_xmitr can be taken with interrupts disabled. In order to avoid a potential system lockup - demonstrated under stress testing conditions on SoC QCS404/5 - make sure we wait for a bounded amount of time. Tested on SoC QCS404. Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-10serial: 8250: Fix TX interrupt handling conditionRautkoski Kimmo EXT1-1/+2
Interrupt handler checked THRE bit (transmitter holding register empty) in LSR to detect if TX fifo is empty. In case when there is only receive interrupts the TX handling got called because THRE bit in LSR is set when there is no transmission (FIFO empty). TX handling caused TX stop, which in RS-485 half-duplex mode actually resets receiver FIFO. This is not desired during reception because of possible data loss. The fix is to check if THRI is set in IER in addition of the TX fifo status. THRI in IER is set when TX is started and cleared when TX is stopped. This ensures that TX handling is only called when there is really transmission on going and an interrupt for THRE and not when there are only RX interrupts. Signed-off-by: Kimmo Rautkoski <ext-kimmo.rautkoski@vaisala.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>