aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/tty
Commit message (Collapse)AuthorAgeFilesLines
* tty: Allow uart_register/unregister/registerAlan Cox2012-06-011-0/+1
| | | | | | | | | | | | commit 1e66cded334e6cea596c72f6f650eec351b1e959 upstream. This is legitimate but because we don't clear the drv->state pointer in the unregister code causes a bogus BUG(). Resolves-bug: https://bugzilla.kernel.org/show_bug.cgi?id=42880 Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Add missing call to uart_update_timeout()Lothar Waßmann2012-06-011-0/+2
| | | | | | | | | | | commit 8b979f7c6bf13a57e7b6002f1175312a44773960 upstream. This patch fixes a problem reported here: http://article.gmane.org/gmane.linux.ports.arm.kernel/155242/match=auart Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* drivers/tty/amiserial.c: add missing tty_unlockJulia Lawall2012-04-271-1/+3
| | | | | | | | | | | commit d3a7b83f865b46bb7b5e1ed18a129ce1af349db4 upstream. tty_unlock is used on all other exits from the function. Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Acked-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* pch_uart: Fix dma channel unallocated issueTomoya MORINAGA2012-04-271-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | commit af6d17cdc8c89aeb3101f0d27cd32fc0592b40b2 upstream. This driver anticipates pch_uart_verify_port() is not called during installation. However, actually pch_uart_verify_port() is called during installation. As a result, memory access violation occurs like below. 0. initial value: use_dma=0 1. starup() - dma channel is not allocated because use_dma=0 2. pch_uart_verify_port() - Set use_dma=1 3. UART processing acts DMA mode because use_dma=1 - memory access violation occurs! This patch fixes the issue. Solution: Whenever pch_uart_verify_port() is called and then dma channel is not allocated, the channel should be allocated. Signed-off-by: Tomoya MORINAGA <tomoya.rohm@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ARM: clps711x: serial driver hungs are a result of call disable_irq within ISRAlexander Shiyan2012-04-271-6/+8
| | | | | | | | | | | | commit 7a6fbc9a887193a1e9f8658703881c528040afbc upstream. Since 2.6.30-rc1 clps711x serial driver hungs system. This is a result of call disable_irq from ISR. synchronize_irq waits for end of interrupt and goes to infinite loop. This patch fix this problem. Signed-off-by: Alexander Shiyan <shc_work@mail.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* 8250_pci: Fix kernel panic when pch_uart is disabledTomoya MORINAGA2012-04-221-0/+10
| | | | | | | | | | | | | | | | | | | | | commit 64d91cfaade2155ad048fe3b65238a052e29dde4 upstream. Currently, ".setup" function is not set. As a result, when detecting our IOH's uart device without pch_uart, kernel panic occurs at the following of pciserial_init_ports(). for (i = 0; i < nr_ports; i++) { if (quirk->setup(priv, board, &serial_port, i)) break; So, this patch adds the ".setup" function. We can use pci_default_setup because our IOH's uart is compatible with 16550. Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.lapis-semi.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Tomoya MORINAGA <tomoya.rohm@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* pch_uart: Set PCIe bus number using probe parameterTomoya MORINAGA2012-04-221-1/+2
| | | | | | | | | | | | | commit 6c4b47d243112e98811ce0da7bbb32cc3857dd1a upstream. Currently, PCIe bus number is set as fixed value "2". However, PCIe bus number is not always "2". This patch sets bus number using probe() parameter. Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com> Signed-off-by: Tomoya MORINAGA <tomoya.rohm@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: PL011: move interrupt clearingLinus Walleij2012-04-221-4/+4
| | | | | | | | | | | | | | | | | | | | | commit c3d8b76f61586714cdc5f219ba45592a54caaa55 upstream. Commit 360f748b204275229f8398cb2f9f53955db1503b "serial: PL011: clear pending interrupts" attempts to clear interrupts by writing to a yet-unassigned memory address. This fixes the issue. The breaking patch is marked for stable so should be carried along with the other patch. Cc: Shreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Nicolas Pitre <nico@fluxnic.net> Reported-by: Viresh Kumar <viresh.kumar@st.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: PL011: clear pending interruptsLinus Walleij2012-04-221-4/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | commit 9b96fbacda34079dea0638ee1e92c56286f6114a upstream. Chanho Min reported that when the boot loader transfers control to the kernel, there may be pending interrupts causing the UART to lock up in an eternal loop trying to pick tokens from the FIFO (since the RX interrupt flag indicates there are tokens) while in practice there are no tokens - in fact there is only a pending IRQ flag. This patch address the issue with a combination of two patches suggested by Russell King that clears and mask all interrupts at probe() and clears any pending error and RX interrupts at port startup time. We suspect the spurious interrupts are a side-effect of switching the UART from FIFO to non-FIFO mode. Cc: Shreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com> Reported-by: Chanho Min <chanho0207@gmail.com> Suggested-by: Russell King <linux@arm.linux.org.uk> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Jong-Sung Kim <neidhard.kim@lge.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: serial: altera_uart: Check for NULL platform_data in probe.Yuriy Kozlov2012-04-221-2/+2
| | | | | | | | | | | commit acede70d6561f2d042d9dbb153d9a3469479c0ed upstream. Follow altera_jtag_uart. This fixes a crash if there is a mistake in the DTS. Signed-off-by: Yuriy Kozlov <ykozlov@ptcusa.com> Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: sh-sci: fix a race of DMA submit_tx on transferYoshii Takashi2012-04-021-5/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 49d4bcaddca977fffdea8b0b71f6e5da96dac78e upstream. When DMA is enabled, sh-sci transfer begins with uart_start() sci_start_tx() if (cookie_tx < 0) schedule_work() Then, starts DMA when wq scheduled, -- (A) process_one_work() work_fn_rx() cookie_tx = desc->submit_tx() And finishes when DMA transfer ends, -- (B) sci_dma_tx_complete() async_tx_ack() cookie_tx = -EINVAL (possible another schedule_work()) This A to B sequence is not reentrant, since controlling variables (for example, cookie_tx above) are not queues nor lists. So, they must be invoked as A B A B..., otherwise results in kernel crash. To ensure the sequence, sci_start_tx() seems to test if cookie_tx < 0 (represents "not used") to call schedule_work(). But cookie_tx will not be set (to a cookie, also means "used") until in the middle of work queue scheduled function work_fn_tx(). This gap between the test and set allows the breakage of the sequence under the very frequently call of uart_start(). Another gap between async_tx_ack() and another schedule_work() results in the same issue, too. This patch introduces a new condition "cookie_tx == 0" just to mark it is "busy" and assign it within spin-locked region to fill the gaps. Signed-off-by: Takashi Yoshii <takashi.yoshii.zj@renesas.com> Reviewed-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Signed-off-by: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* TTY: Wrong unicode value copied in con_set_unimap()Liz Clark2012-04-021-8/+43
| | | | | | | | | | | | | | | | | | commit 4a4c61b7ce26bfc9d49ea4bd121d52114bad9f99 upstream. Bugzilla 40012: PIO_UNIMAP bug: error updating Unicode-to-font map https://bugzilla.kernel.org/show_bug.cgi?id=40012 The unicode font map for the virtual console is a 32x32x64 table which allocates rows dynamically as entries are added. The unicode value increases sequentially and should count all entries even in empty rows. The defect is when copying the unicode font map in con_set_unimap(), the unicode value is not incremented properly. The wrong unicode value is entered in the new font map. Signed-off-by: Liz Clark <liz.clark@hp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: moxa: fix bit test in moxa_start()Dan Carpenter2012-04-021-1/+1
| | | | | | | | | | | | | commit 58112dfbfe02d803566a2c6c8bd97b5fa3c62cdc upstream. This is supposed to be doing a shift before the comparison instead of just doing a bitwise AND directly. The current code means the start() just returns without doing anything. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* drivers/tty/vt/vt_ioctl.c: fix KDFONTOP 32bit compatibility layerSamuel Thibault2012-02-131-1/+0
| | | | | | | | | | | | | | | | | | | | | | | commit cbcb8346054073d000ecac324763372d6abd44ac upstream. KDFONTOP(GET) currently fails with EIO when being run in a 32bit userland with a 64bit kernel if the font width is not 8. This is because of the setting of the KD_FONT_FLAG_OLD flag, which makes con_font_get return EIO in such case. This flag should *not* be set for KDFONTOP, since it's actually the whole point of this flag (see comment in con_font_set for instance). Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Cc: Arthur Taylor <art@ified.ca> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* jsm: Fixed EEH recovery errorLucas Kannebley Tavares2012-02-031-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 26aa38cafae0dbef3b2fe75ea487c83313c36d45 upstream. There was an error on the jsm driver that would cause it to be unable to recover after a second error is detected. At the first error, the device recovers properly: [72521.485691] EEH: Detected PCI bus error on device 0003:02:00.0 [72521.485695] EEH: This PCI device has failed 1 times in the last hour: ... [72532.035693] ttyn3 at MMIO 0x0 (irq = 49) is a jsm [72532.105689] jsm: Port 3 added However, at the second error, it cascades until EEH disables the device: [72631.229549] Call Trace: ... [72641.725687] jsm: Port 3 added [72641.725695] EEH: Detected PCI bus error on device 0003:02:00.0 [72641.725698] EEH: This PCI device has failed 3 times in the last hour: It was caused because the PCI state was not being saved after the first restore. Therefore, at the second recovery the PCI state would not be restored. Signed-off-by: Lucas Kannebley Tavares <lucaskt@linux.vnet.ibm.com> Signed-off-by: Breno Leitao <brenohl@br.ibm.com> Acked-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: amba-pl011: lock console writes against interruptsRabin Vincent2012-02-031-0/+14
| | | | | | | | | | | | | | | | | | | | | | | commit ef605fdb33883d687cff5ba75095a91b313b4966 upstream. Protect against pl011_console_write() and the interrupt for the console UART running concurrently on different CPUs. Otherwise the console_write could spin for a long time waiting for the UART to become not busy, while the other CPU continuously services UART interrupts and keeps the UART busy. The checks for sysrq and oops_in_progress are taken from 8250.c. Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com> Reviewed-by: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com> Reviewed-by: Bibek Basu <bibek.basu@stericsson.com> Reviewed-by: Shreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* TTY: fix UV serial console regressionJiri Slaby2012-02-031-5/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 0eee50af5b13e00b3fb7a5fe8480419a71b8235d upstream. Commit 74c2107759d (serial: Use block_til_ready helper) and its fixup 3f582b8c110 (serial: fix termios settings in open) introduced a regression on UV systems. The serial eventually freezes while being used. It's completely unpredictable and sometimes needs a heap of traffic to happen first. To reproduce this, yast installation was used as it turned out to be pretty reliable in reproducing. Especially during installation process where one doesn't have an SSH daemon running. And no monitor as the HW is completely headless. So this was fun to find. Given the machine doesn't boot on vanilla before 2.6.36 final. (And the commits above are older.) Unless there is some bad race in the code, the hardware seems to be pretty broken. Otherwise pure MSR read should not cause such a bug, or? So to prevent the bug, revert to the old behavior. I.e. read modem status only if we really have to -- for non-CLOCAL set serials. Non-CLOCAL works on this hardware OK, I tried. See? I don't. And document that shit. Signed-off-by: Jiri Slaby <jslaby@suse.cz> References: https://lkml.org/lkml/2011/12/6/573 References: https://bugzilla.novell.com/show_bug.cgi?id=718518 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* atmel_serial: fix spinlock lockup in RS485 codeClaudio Scordino2012-01-121-2/+3
| | | | | | | | | | | | | | | commit dbf1115d3f8c7052788aa4e6e46abd27f3b3eeba upstream. Patch to fix a spinlock lockup in the driver that sometimes happens when the tasklet starts. Signed-off-by: Claudio Scordino <claudio@evidence.eu.com> Signed-off-by: Dave Bender <codehero@gmail.com> Tested-by: Dave Bender <codehero@gmail.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* TTY: ldisc, wait for ldisc infinitely in hangupJiri Slaby2011-11-261-2/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 0c73c08ec73dbe080b9ec56696ee21d32754d918 upstream. For /dev/console case, we do not kill all ldisc users. It's due to redirected_tty_write test in __tty_hangup. In that case there still might be a process waiting e.g. in n_tty_read for input. We wait for such processes to disappear. The problem is that we use a timeout. After this timeout, we continue closing the ldisc and start freeing tty resources. It obviously leads to crashes when the other process is woken. So to fix this, we wait infinitely before reiniting the ldisc. (The tiocsetd remains untouched -- times out after 5s.) This is nicely reproducible with this run from shell: exec 0<>/dev/console 1<>/dev/console 2<>/dev/console and stopping a getty like: systemctl stop serial-getty@ttyS0.service The crash proper may be produced only under load or with constified timing the same as for 92f6fa09b. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Dave Young <hidave.darkstar@gmail.com> Cc: Dave Jones <davej@redhat.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Dmitriy Matrosov <sgf.dma@gmail.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* TTY: ldisc, move wait idle to callerJiri Slaby2011-11-261-2/+2
| | | | | | | | | | | | | | | | | | | commit 300420722e0734a4254f3b634e0f82664495d210 upstream. It is the only place where reinit is called from. And we really need to wait for the old ldisc to go once. Actually this is the place where the waiting originally was (before removed and re-added later). This will make the fix in the following patch easier to implement. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Dave Young <hidave.darkstar@gmail.com> Cc: Dave Jones <davej@redhat.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Dmitriy Matrosov <sgf.dma@gmail.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* TTY: ldisc, allow waiting for ldisc arbitrarily longJiri Slaby2011-11-261-5/+6
| | | | | | | | | | | | | | | | | | | | commit df92d0561de364de53c42abc5d43e04ab6f326a5 upstream. To fix a nasty bug in ldisc hup vs. reinit we need to wait infinitely long for ldisc to be gone. So here we add a parameter to tty_ldisc_wait_idle to allow that. This is only a preparation for the real fix which is done in the following patches. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Dave Young <hidave.darkstar@gmail.com> Cc: Dave Jones <davej@redhat.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Dmitriy Matrosov <sgf.dma@gmail.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: hvc_dcc: Fix duplicate character inputsStephen Boyd2011-11-261-0/+2
| | | | | | | | | | | | | | | | | | | | | | | commit c2a3e84f950e7ddba1f3914b005861d46ae60359 upstream. Reading from the DCC grabs a character from the buffer and clears the status bit. Since this is a context-changing operation, instructions following the character read that rely on the status bit being accurate need to be synchronized with an ISB. In this case, the status bit check needs to execute after the character read otherwise we run the risk of reading the character and checking the status bit before the read can clear the status bit in the first place. When this happens, the user will see the same character they typed twice, instead of once. Add an ISB after the read and the write, so that the status check is synchronized with the read/write operations. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* pch_uart: Support new device LAPIS Semiconductor ML7831 IOHTomoya MORINAGA2011-11-262-7/+15
| | | | | | | | | | | commit 8249f743f732ccbc3056428945ab1d9bd36d46bf upstream. ML7831 is companion chip for Intel Atom E6xx series. Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.lapis-semi.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* pch_uart: Fix DMA resource leak issueTomoya MORINAGA2011-11-261-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 90f04c2926cfb5bf74533b0a7766bc896f6a0c0e upstream. Changing UART mode PIO->DMA->PIO->DMA like below, pch_uart driver can't get DMA channel resource. setserial /dev/ttyPCH0 ^low_latency setserial /dev/ttyPCH0 low_latency CAUSE: Changing mode using setserial command, ".startup" function which gets DMA channel is called before ".verify_port" function which sets dma-flag(use_dma/use_dma_flag) as 1. PIO->DMA .startup: Since dma-flag is 0, DMA channel is not requested. .verify_port: dma-flag is set as 1. .shutdown: N/A DMA->PIO .startup: Since dma-flag is 1, DMA channel is requested. .verify_port: dma-flag is set as 0. .shutdown: Since dma-flag is 0, DMA channel is not released. This means DMA channel resource leak occurs. Next time, this driver can't get DMA channel resource forever. MODIFICATION: Currently, when release DMA channel resource, this driver checks dma-flag. However, this specification occurs the above issue. This driver must check whether dma_request_channel is executed or not. The values are saved in private data variable "chan_tx/chan_tx". These variables mean if the value is NULL, DMA channel is not requested, if not NULL, DMA channel is requested. This patch fixes the issue. Signed-off-by: Tomoya MORINAGA <tomoya.rohm@gmail.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* pch_uart: Fix hw-flow control issueTomoya MORINAGA2011-11-261-0/+1
| | | | | | | | | | | | | commit a1d7cfe29f13cf45f8094929864b9c66bf0cd91b upstream. Using hardware flow control, currently, register of the control-bit(AFE) is not set. This patch fixes the issue. Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.lapis-semi.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* jsm: remove buggy write queueThadeu Lima de Souza Cascardo2011-11-114-103/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 9d898966c4a07e4a5092215b5a2829d0ef02baa2 upstream. jsm uses a write queue that copies from uart_core circular buffer. This copying however has some bugs, like not wrapping the head counter. Since this write queue is also a circular buffer, the consumer function is ready to use the uart_core circular buffer directly. This buggy copying function was making some bytes be dropped when transmitting to a raw tty, doing something like this. [root@hostname ~]$ cat /dev/ttyn1 > cascardo/dump & [1] 2658 [root@hostname ~]$ cat /proc/tty/drivers > /dev/ttyn0 [root@hostname ~]$ cat /proc/tty/drivers /dev/tty /dev/tty 5 0 system:/dev/tty /dev/console /dev/console 5 1 system:console /dev/ptmx /dev/ptmx 5 2 system /dev/vc/0 /dev/vc/0 4 0 system:vtmaster jsm /dev/ttyn 250 0-31 serial serial /dev/ttyS 4 64-95 serial hvc /dev/hvc 229 0-7 system pty_slave /dev/pts 136 0-1048575 pty:slave pty_master /dev/ptm 128 0-1048575 pty:master unknown /dev/tty 4 1-63 console [root@hostname ~]$ cat cascardo/dump /dev/tty /dev/tty 5 0 system:/dev/tty /dev/console /dev/console 5 1 system:console /dev/ptmx /dev/ptmx 5 2 system /dev/vc/0 /dev/vc/0 4 0 system:vtmaste[root@hostname ~]$ This patch drops the driver write queue entirely, using the circular buffer from uart_core only. Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* serial-core: power up uart port early before we do set_termios when resumingNing Jiang2011-11-111-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 94abc56f4d90f289ea32a0a11d3577fcd8cb28fb upstream. The following patch removed uart_change_pm() in uart_resume_port(): commit 5933a161abcb8d83a2c145177f48027c3c0a8995 Author: Yin Kangkai <kangkai.yin@linux.intel.com> serial-core: reset the console speed on resume It will break the pxa serial driver when the system resumes from suspend mode as it will try to set baud rate divider register in set_termios but with clock off. The register value can not be set correctly on some platform if the clock is disabled. The pxa driver will check the value and report the following warning: ------------[ cut here ]------------ WARNING: at drivers/tty/serial/pxa.c:545 serial_pxa_set_termios+0x1dc/0x250() Modules linked in: [<c0281f30>] (unwind_backtrace+0x0/0xf0) from [<c029341c>] (warn_slowpath_common+0x4c/0x64) [<c029341c>] (warn_slowpath_common+0x4c/0x64) from [<c029344c>] (warn_slowpath_null+0x18/0x1c) [<c029344c>] (warn_slowpath_null+0x18/0x1c) from [<c044b1e4>] (serial_pxa_set_termios+0x1dc/0x250) [<c044b1e4>] (serial_pxa_set_termios+0x1dc/0x250) from [<c044a840>] (uart_resume_port+0x128/0x2dc) [<c044a840>] (uart_resume_port+0x128/0x2dc) from [<c044bbe0>] (serial_pxa_resume+0x18/0x24) [<c044bbe0>] (serial_pxa_resume+0x18/0x24) from [<c0454d34>] (platform_pm_resume+0x40/0x4c) [<c0454d34>] (platform_pm_resume+0x40/0x4c) from [<c0457ebc>] (pm_op+0x68/0xb4) [<c0457ebc>] (pm_op+0x68/0xb4) from [<c0458368>] (device_resume+0xb0/0xec) [<c0458368>] (device_resume+0xb0/0xec) from [<c04584c8>] (dpm_resume+0xe0/0x194) [<c04584c8>] (dpm_resume+0xe0/0x194) from [<c0458588>] (dpm_resume_end+0xc/0x18) [<c0458588>] (dpm_resume_end+0xc/0x18) from [<c02c518c>] (suspend_devices_and_enter+0x16c/0x1ac) [<c02c518c>] (suspend_devices_and_enter+0x16c/0x1ac) from [<c02c5278>] (enter_state+0xac/0xdc) [<c02c5278>] (enter_state+0xac/0xdc) from [<c02c48ec>] (state_store+0xa0/0xbc) [<c02c48ec>] (state_store+0xa0/0xbc) from [<c0408f7c>] (kobj_attr_store+0x18/0x1c) [<c0408f7c>] (kobj_attr_store+0x18/0x1c) from [<c034a6a4>] (sysfs_write_file+0x108/0x140) [<c034a6a4>] (sysfs_write_file+0x108/0x140) from [<c02fb798>] (vfs_write+0xac/0x134) [<c02fb798>] (vfs_write+0xac/0x134) from [<c02fb8cc>] (sys_write+0x3c/0x68) [<c02fb8cc>] (sys_write+0x3c/0x68) from [<c027c700>] (ret_fast_syscall+0x0/0x2c) ---[ end trace 88289eceb4675b04 ]--- This patch fix the problem by adding the power on opertion back for uart console when console_suspend_enabled is true. Signed-off-by: Ning Jiang <ning.jiang@marvell.com> Tested-by: Mayank Rana <mrana@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* serial: pxa: work around for errata #20Marcus Folkesson2011-11-111-0/+20
| | | | | | | | | | | | | commit e44aabd649c80e8be16ede3ed3cbff6fb2561ca9 upstream. Errata E20: UART: Character Timeout interrupt remains set under certain software conditions. Implication: The software servicing the UART can be trapped in an infinite loop. Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* TTY: pty, release tty in all ptmx_open fail pathsJiri Slaby2011-11-111-5/+5
| | | | | | | | | | | | | | | | | | commit 1177c0efc04d032644895b8d757f55b433912596 upstream. Mistakenly, commit 64ba3dc3143d (tty: never hold BTM while getting tty_mutex) switched one fail path in ptmx_open to not free the newly allocated tty. Fix that by jumping to the appropriate place. And rename the labels so that it's clear what is going on there. Introduced-in: v2.6.36-rc2 Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* TTY: make tty_add_file non-failingJiri Slaby2011-11-112-17/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit fa90e1c935472281de314e6d7c9a37db9cbc2e4e upstream. If tty_add_file fails at the point it is now, we have to revert all the changes we did to the tty. It means either decrease all refcounts if this was a tty reopen or delete the tty if it was newly allocated. There was a try to fix this in v3.0-rc2 using tty_release in 0259894c7 (TTY: fix fail path in tty_open). But instead it introduced a NULL dereference. It's because tty_release dereferences filp->private_data, but that one is set even in our tty_add_file. And when tty_add_file fails, it's still NULL/garbage. Hence tty_release cannot be called there. To circumvent the original leak (and the current NULL deref) we split tty_add_file into two functions, making the latter non-failing. In that case we may do the former early in open, where handling failures is easy. The latter stays as it is now. So there is no change in functionality. The original bug (leak) was introduced by f573bd176 (tty: Remove __GFP_NOFAIL from tty_add_file()). Thanks Dan for reporting this. Later, we may split tty_release into more functions and call only some of them in this fail path instead. (If at all possible.) Introduced-in: v2.6.37-rc2 Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* TTY: drop driver reference in tty_open fail pathJiri Slaby2011-11-111-0/+1
| | | | | | | | | | | | | | | | | | | | commit c290f8358acaeffd8e0c551ddcc24d1206143376 upstream. When tty_driver_lookup_tty fails in tty_open, we forget to drop a reference to the tty driver. This was added by commit 4a2b5fddd5 (Move tty lookup/reopen to caller). Fix that by adding tty_driver_kref_put to the fail path. I will refactor the code later. This is for the ease of backporting to stable. Introduced-in: v2.6.28-rc2 Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Acked-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* cris: fix a build error in drivers/tty/serial/crisv10.cWANG Cong2011-11-111-2/+2
| | | | | | | | | | | | | | | | | | | | | commit 2f7861de111bb8e33e6ab9f9607583c6fbc00132 upstream. This patch fixes the following build error: drivers/tty/serial/crisv10.c:4453: error: 'if_ser0' undeclared (first use in this function): 2 errors in 2 logs v3.1-rc4/cris/cris-allmodconfig v3.1-rc4/cris/cris-allyesconfig drivers/tty/serial/crisv10.c:4453: error: (Each undeclared identifier is reported only once: 2 errors in 2 logs v3.1-rc4/cris/cris-allmodconfig v3.1-rc4/cris/cris-allyesconfig drivers/tty/serial/crisv10.c:4453: error: for each function it appears in.): 2 errors in 2 logs v3.1-rc4/cris/cris-allmodconfig v3.1-rc4/cris/cris-allyesconfig "if_ser0" is a typo, it should be "if_serial_0". Cc: Mikael Starvik <starvik@axis.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* TTY: pty, fix pty countingJiri Slaby2011-10-032-4/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 24d406a6bf736f7aebdc8fa0f0ec86e0890c6d24 upstream. tty_operations->remove is normally called like: queue_release_one_tty ->tty_shutdown ->tty_driver_remove_tty ->tty_operations->remove However tty_shutdown() is called from queue_release_one_tty() only if tty_operations->shutdown is NULL. But for pty, it is not. pty_unix98_shutdown() is used there as ->shutdown. So tty_operations->remove of pty (i.e. pty_unix98_remove()) is never called. This results in invalid pty_count. I.e. what can be seen in /proc/sys/kernel/pty/nr. I see this was already reported at: https://lkml.org/lkml/2009/11/5/370 But it was not fixed since then. This patch is kind of a hackish way. The problem lies in ->install. We allocate there another tty (so-called tty->link). So ->install is called once, but ->remove twice, for both tty and tty->link. The fix here is to count both tty and tty->link and divide the count by 2 for user. And to have ->remove called, let's make tty_driver_remove_tty() global and call that from pty_unix98_shutdown() (tty_operations->shutdown). While at it, let's document that when ->shutdown is defined, tty_shutdown() is not called. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: Add "spi:" prefix for spi modaliasAxel Lin2011-10-033-3/+3
| | | | | | | | | | | | | commit 8c4074cd2254606aeb788d518ccc27c9f97129e1 upstream. Since commit e0626e38 (spi: prefix modalias with "spi:"), the spi modalias is prefixed with "spi:". This patch adds "spi:" prefix and removes "-spi" suffix in the modalias. Signed-off-by: Axel Lin <axel.lin@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* 8250: Fix race condition in serial8250_backup_timeout().Al Cooper2011-10-031-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit dbb3b1ca5609d1f3848cd387d06cc60aaacf7f98 upstream. This is to fix an issue where output will suddenly become very slow. The problem occurs on 8250 UARTS with the hardware bug UART_BUG_THRE. BACKGROUND For normal UARTs (without UART_BUG_THRE): When the serial core layer gets new transmit data and the transmitter is idle, it buffers the data and calls the 8250s' serial8250_start_tx() routine which will simply enable the TX interrupt in the IER register and return. This should immediately fire a THRE interrupt and begin transmitting the data. For buggy UARTs (with UART_BUG_THRE): merely enabling the TX interrupt in IER does not necessarily generate a new THRE interrupt. Therefore, a background timer periodically checks to see if there is pending data, and starts transmission if that is the case. The bug happens on SMP systems when the system has nothing to transmit, the transmit interrupt is disabled and the following sequence occurs: - CPU0: The background timer routine serial8250_backup_timeout() starts and saves the state of the interrupt enable register (IER) and then disables all interrupts in IER. NOTE: The transmit interrupt (TI) bit is saved as disabled. - CPU1: The serial core gets data to transmit, grabs the port lock and calls serial8250_start_tx() which enables the TI in IER. - CPU0: serial8250_backup_timeout() waits for the port lock. - CPU1: finishes (with TI enabled) and releases the port lock. - CPU0: serial8250_backup_timeout() calls the interrupt routine which will transmit the next fifo's worth of data and then restores the IER from the previously saved value (TI disabled). At this point, as long as the serial core has more transmit data buffered, it will not call serial8250_start_tx() again and the background timer routine will slowly transmit the data. The fix is to have serial8250_start_tx() get the port lock before it saves the IER state and release it after restoring IER. This will prevent serial8250_start_tx() from running in parallel. Signed-off-by: Al Cooper <alcooperx@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* 8250_pci: add support for Rosewill RC-305 4x serial port cardEric Smith2011-10-031-1/+5
| | | | | | | | | | | | | | | | | | | | commit 44178176ecc55ad370b837dd2c4b4b8bed1e3823 upstream. This patch adds support for the Rosewill RC-305 four-port PCI serial card, and probably any other four-port serial cards based on the Moschip MCS9865 chip, assuming that the EEPROM on the card was programmed in accordance with Table 6 of the MCS9865 EEPROM Application Note version 0.3 dated 16-May-2008, available from the Moschip web site (registration required). This patch is based on an earlier patch [1] for the SYBA 6x serial port card by Ira W. Snyder. [1]: http://www.gossamer-threads.com/lists/linux/kernel/1162435 Signed-off-by: Eric Smith <eric@brouhaha.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* serial: 8250_pnp: add Intermec CV60 touchscreen deviceBjorn Helgaas2011-10-031-0/+3
| | | | | | | | | | | | | | commit ab8ba3a2d2cba6a658ef596cd5b2e0905b6c8a9f upstream. It would have been nice if Intermec had supplied a PNP0501 _CID for the COM3 device, but they didn't, so we have to recognize it explicitly. Reference: https://bugzilla.kernel.org/show_bug.cgi?id=40612 CC: Jeff Chua <jeff.chua.linux@gmail.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* omap-serial: Allow IXON and IXOFF to be disabled.Nick Pelly2011-10-031-2/+1
| | | | | | | | | | | | | | commit b280a97d1caf6fe1d38b51ebb31219391f5ad1a0 upstream. Fixes logic bug that software flow control cannot be disabled, because serial_omap_configure_xonxoff() is not called if both IXON and IXOFF bits are cleared. Signed-off-by: Nick Pelly <npelly@google.com> Acked-by: Govindraj.R <govindraj.raja@ti.com> Tested-by: Govindraj.R <govindraj.raja@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* hvc_console: Improve tty/console put_chars handlingHendrik Brueckner2011-08-041-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | commit 8c2381af0d3ef62a681dac5a141b6dabb27bf2e1 upstream. Currently, the hvc_console_print() function drops console output if the hvc backend's put_chars() returns 0. This patch changes this behavior to allow a retry through returning -EAGAIN. This change also affects the hvc_push() function. Both functions are changed to handle -EAGAIN and to retry the put_chars() operation. If a hvc backend returns -EAGAIN, the retry handling differs: - hvc_console_print() spins to write the complete console output. - hvc_push() behaves the same way as for returning 0. Now hvc backends can indirectly control the way how console output is handled through the hvc console layer. Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Acked-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* SERIAL: SC26xx: Fix link error.Ralf Baechle2011-08-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | commit f2eb3cdf14457fccb14ae8c4d7d7cee088cd3957 upstream. Kconfig allows enabling console support for the SC26xx driver even when it's configured as a module resulting in a: ERROR: "uart_console_device" [drivers/tty/serial/sc26xx.ko] undefined! modpost error since the driver was merged in eea63e0e8a60d00485b47fb6e75d9aa2566b989b [SC26XX: New serial driver for SC2681 uarts] in 2.6.25. Fixed by only allowing console support to be enabled if the driver is builtin. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty/serial: Fix XSCALE serial ports, e.g. ce4100Stephen Warren2011-08-041-1/+1
| | | | | | | | | | | | | | | | | | commit 5568181f188ae9485a0cdbea5ea48f63d186a298 upstream. Commit 4539c24fe4f92c09ee668ef959d3e8180df619b9 "tty/serial: Add explicit PORT_TEGRA type" introduced separate flags describing the need for IER bits UUE and RTOIE. Both bits are required for the XSCALE port type. While that patch updated uart_config[] as required, the auto-probing code wasn't updated to set the RTOIE flag when an XSCALE port type was detected. This caused such ports to stop working. This patch rectifies that. Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* n_gsm: fix the wrong FCS handlingDu, Alek2011-08-041-4/+0
| | | | | | | | | | | | | | | commit f086ced17191fa0c5712539d2b680eae3dc972a1 upstream. FCS could be GSM0_SOF, so will break state machine... [This byte isn't quoted in any way so a SOF here doesn't imply an error occurred.] Signed-off-by: Alek Du <alek.du@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> [Trivial but best backported once its in 3.1rc I think] Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Merge branch 'at91/fixes' of ↵Linus Torvalds2011-07-041-1/+2
|\ | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/arm/linux-2.6-arm-soc * 'at91/fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/linux-2.6-arm-soc: AT91: Change nand buswidth logic to match hardware default configuration at91: Use "pclk" as con_id on at91cap9 and at91rm9200 at91: fix udc, ehci and mmc clock device name for cap9/9g45/9rl atmel_serial: fix internal port num at91: fix at91_set_serial_console: use platform device id
| * atmel_serial: fix internal port numJean-Christophe PLAGNIOL-VILLARD2011-06-251-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | the atmel_ports is link to the console number and not the device id this was not detected on at91 as we always register the dbgu on the console as ttyS0 tested on at91sam9263 by setting the dbgu as ttyS1 and use as console diff --git a/arch/arm/mach-at91/board-sam9263ek.c b/arch/arm/mach-at91/board-sam9263ek.c index 70e5646..9b8a14f 100644 - a/arch/arm/mach-at91/board-sam9263ek.c + b/arch/arm/mach-at91/board-sam9263ek.c @@ -58,14 +58,14 @@ static void __init ek_init_early(void) /* Initialize processor: 16.367 MHz crystal */ at91_initialize(16367660); - /* DBGU on ttyS0. (Rx & Tx only) */ - at91_register_uart(0, 0, 0); + /* DBGU on ttyS1. (Rx & Tx only) */ + at91_register_uart(0, 1, 0); - /* USART0 on ttyS1. (Rx, Tx, RTS, CTS) */ - at91_register_uart(AT91SAM9263_ID_US0, 1, ATMEL_UART_CTS | ATMEL_UART_RTS); + /* USART0 on ttyS0. (Rx, Tx, RTS, CTS) */ + at91_register_uart(AT91SAM9263_ID_US0, 0, ATMEL_UART_CTS | ATMEL_UART_RTS); - /* set serial console to ttyS0 (ie, DBGU) */ - at91_set_serial_console(0); + /* set serial console to ttyS1 (ie, DBGU) */ + at91_set_serial_console(1); } /* Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Cc: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Alan Cox <alan@linux.intel.com> Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
* | Merge branch 'tty-linus' of ↵Linus Torvalds2011-06-289-15/+223
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6 * 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: serial: bcm63xx_uart: fix irq storm after rx fifo overrun. amba pl011: platform data for reg lockup and glitch v2 amba pl011: workaround for uart registers lockup tty: n_gsm: improper skb_pull() use was leaking framed data tty: n_gsm: Fixed logic to decode break signal from modem status TTY: ntty, add one more sanity check TTY: ldisc, do not close until there are readers 8250: Fix capabilities when changing the port type 8250_pci: Fix missing const from merges ARM: SAMSUNG: serial: Fix on handling of one clock source for UART serial: ioremap warning fix for jsm driver. 8250_pci: add -ENODEV code for Intel EG20T PCH
| * | serial: bcm63xx_uart: fix irq storm after rx fifo overrun.Maxime Bizon2011-06-161-4/+14
| | | | | | | | | | | | | | | | | | | | | RX fifo reset is required to clear irq. Signed-off-by: Maxime Bizon <mbizon@freebox.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * | amba pl011: workaround for uart registers lockupShreshtha Kumar Sahu2011-06-161-1/+122
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This workaround aims to break the deadlock situation which raises during continuous transfer of data for long duration over uart with hardware flow control. It is observed that CTS interrupt cannot be cleared in uart interrupt register (ICR). Hence further transfer over uart gets blocked. It is seen that during such deadlock condition ICR don't get cleared even on multiple write. This leads pass_counter to decrease and finally reach zero. This can be taken as trigger point to run this UART_BT_WA. Workaround backups the register configuration, does soft reset of UART using BIT-0 of PRCC_K_SOFTRST_SET/CLEAR registers and restores the registers. This patch also provides support for uart init and exit function calls if present. Signed-off-by: Shreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * | tty: n_gsm: improper skb_pull() use was leaking framed dataRuss Gorby2011-06-161-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | gsm_dlci_data_output_framed() was doing: memcpy(dp, skb_pull(dlci->skb, len), len); The problem is skb_pull() returns the post-increment data ptr so the first chunk of dlci->skb->data is leaked. Signed-off-by: Russ Gorby <russ.gorby@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * | tty: n_gsm: Fixed logic to decode break signal from modem statusRuss Gorby2011-06-161-5/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The modem status can be one or 2 octets and contains the V.24 signals and in the 2 octet case also the break signal. We were improperly decoding the break signal from the modem in the 2 octet case. Signed-off-by: Russ Gorby <russ.gorby@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * | TTY: ntty, add one more sanity checkJiri Slaby2011-06-071-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the previous patch, we fixed another bug where read_buf was freed while we still was in n_tty_read. We currently check whether read_buf is NULL at the start of the function. Add one more check after we wake up from waiting for input. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>