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* tty: serial: men_z135_uart: Fix driver for changes in hardwareJohannes Thumshirn2015-02-021-46/+109
| | | | | | | | | | | | | | | | | | | | | | 16z135 IP Core has changed so the driver needs to be updated to respect these changes. The following changes have been made: * Don't invert the 16z135 modem status register when reading. * Add module parameter to configure the (baud rate dependent) RX timeout. Character timeout in seconds = (timeout_reg * baud_reg * 4)/freq_reg. * Enable the handling of UART core's automatic flow control feature. When AFE is active disable generation of modem status IRQs. * Rework the handling of IRQs to be conform with newer FPGA versions and take precautions not to miss an interrupt because of the destructive read of the IIR register. * Correct men_z135_handle_modem_status(), MSR is stat_reg[15:8] not stat_reg[7:0] * Correct calling of uart_handle_{dcd,cts}_change() * Reset CLOCAL when CRTSCTS is set Signed-off-by: Johannes Thumshirn <johannes.thumshirn@men.de> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: Simplify console suspend logic in uart_suspend_port()Peter Hurley2015-02-021-18/+17
| | | | | | | | | | | | | | | | | | | When the uart port being suspended is a console and consoles are not suspending (kernel command line contains no_console_suspend), then no action is performed for that port, and the function can return early. If the function has not returned early, then one of the conditions is not true, so the expression (console_suspend_enabled || !uart_console(uport)) must be true and can be eliminated. Similarly, the expression (console_suspend_enabled && uart_console(uport)) simplifies to just uart_console(uport). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Specify PCI based UART for earlyprintkStuart R. Anderson2015-02-021-16/+166
| | | | | | | | | | Add support for specifying PCI based UARTs for earlyprintk using a syntax like "earlyprintk=pciserial,00:18.1,115200", where 00:18.1 is the BDF of a UART device. [Slightly tidied from Stuart's original patch] Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* n_tty: Fix signal handling flushesPeter Hurley2015-02-023-15/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRKINT and ISIG requires input and output flush when a signal char is received. However, the order of operations is significant since parallel i/o may be ongoing. Merge the signal handling for BRKINT with ISIG handling. Process the signal first. This ensures any ongoing i/o is aborted; without this, a waiting writer may continue writing after the flush occurs and after the signal char has been echoed. Write lock the termios_rwsem, which excludes parallel writers from pushing new i/o until after the output buffers are flushed; claiming the write lock is necessary anyway to exclude parallel readers while the read buffer is flushed. Subclass the termios_rwsem for ptys since the slave pty performing the flush may appear to reorder the termios_rwsem->tty buffer lock lock order; adding annotation clarifies that slave tty_buffer lock-> slave termios_rwsem -> master tty_buffer lock is a valid lock order. Flush the echo buffer. In this context, the echo buffer is 'output'. Otherwise, the output will appear discontinuous because the output buffer was cleared which contains older output than the echo buffer. Open-code the read buffer flush since the input worker does not need kicking (this is the input worker). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* pty: Fix buffer flush deadlockPeter Hurley2015-02-023-1/+19
| | | | | | | | | | | | | | | | | The pty driver does not clear its write buffer when commanded. This is to avoid an apparent deadlock between parallel flushes from both pty ends; specifically when handling either BRK or INTR input. However, parallel flushes from this source is not possible since the pty master can never be set to BRKINT or ISIG. Parallel flushes from other sources are possible but these do not threaten deadlocks. Annotate the tty buffer mutex for lockdep to represent the nested tty_buffer locking which occurs when the pty slave is processing input (its buffer mutex held) and receives INTR or BRK and acquires the linked tty buffer mutex via tty_buffer_flush(). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Make lock subclasses available for other tty locksPeter Hurley2015-02-022-11/+18
| | | | | | | | | | | Besides nested legacy_mutex locking which is required on pty pair teardown, other nested pty operations require lock subclassing. Move lock subclass definition to tty interface header, include/linux/tty.h, and document its use. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* n_tty: Fix read buffer overwrite when no newlinePeter Hurley2015-02-021-30/+62
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In canon mode, the read buffer head will advance over the buffer tail if the input > 4095 bytes without receiving a line termination char. Discard additional input until a line termination is received. Before evaluating for overflow, the 'room' value is normalized for I_PARMRK and 1 byte is reserved for line termination (even in !icanon mode, in case the mode is switched). The following table shows the transform: actual buffer | 'room' value before overflow calc space avail | !I_PARMRK | I_PARMRK -------------------------------------------------- 0 | -1 | -1 1 | 0 | 0 2 | 1 | 0 3 | 2 | 0 4+ | 3 | 1 When !icanon or when icanon and the read buffer contains newlines, normalized 'room' values of -1 and 0 are clamped to 0, and 'overflow' is 0, so read_head is not adjusted and the input i/o loop exits (setting no_room if called from flush_to_ldisc()). No input is discarded since the reader does have input available to read which ensures forward progress. When icanon and the read buffer does not contain newlines and the normalized 'room' value is 0, then overflow and room are reset to 1, so that the i/o loop will process the next input char normally (except for parity errors which are ignored). Thus, erasures, signalling chars, 7-bit mode, etc. will continue to be handled properly. If the input char processed was not a line termination char, then the canon_head index will not have advanced, so the normalized 'room' value will now be -1 and 'overflow' will be set, which indicates the read_head can safely be reset, effectively erasing the last char processed. If the input char processed was a line termination, then the canon_head index will have advanced, so 'overflow' is cleared to 0, the read_head is not reset, and 'room' is cleared to 0, which exits the i/o loop (because the reader now have input available to read which ensures forward progress). Note that it is possible for a line termination to be received, and for the reader to copy the line to the user buffer before the input i/o loop is ready to process the next input char. This is why the i/o loop recomputes the room/overflow state with every input char while handling overflow. Finally, if the input data was processed without receiving a line termination (so that overflow is still set), the pty driver must receive a write wakeup. A pty writer may be waiting to write more data in n_tty_write() but without unthrottling here that wakeup will not arrive, and forward progress will halt. (Normally, the pty writer is woken when the reader reads data out of the buffer and more space become available). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* n_tty: Fix PARMRK over-throttlingPeter Hurley2015-02-021-8/+4
| | | | | | | | | | | | | | | | | | | If PARMRK is enabled, the available read buffer space computation is overly-pessimistic, which results in severely throttled i/o, even in the absence of parity errors. For example, if the 4k read buffer contains 1k processed data, the input worker will compute available space of 333 bytes, despite 3k being available. At 1365 chars of processed data, 0 space available is computed. *Divide remaining space* by 3, truncating down (if left == 2, left = 0). Reported-by: Christian Riesch <christian.riesch@omicron.at> Conflicts: drivers/tty/n_tty.c Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* n_tty: Fix unordered accesses to lockless read bufferPeter Hurley2015-02-021-53/+48
| | | | | | | | | | | | | | | | | | | | | Add commit_head buffer index, which the producer-side publishes after input processing in non-canon mode. This ensures the consumer-side observes correctly-ordered writes in non-canonical mode (ie., the buffer data is written before the buffer index is advanced). Fix consumer-side uses of read_cnt() to use commit_head instead. Add required memory barriers to the tail index to guarantee the consumer-side has completed the loads before the producer-side begins writing new data. Open-code the producer-side receive_room() into the i/o loop. Remove no-longer-referenced receive_room(). Based on work by Christian Riesch <christian.riesch@omicron.at> Cc: Christian Riesch <christian.riesch@omicron.at> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* n_tty: Simplify throttle threshold calculationPeter Hurley2015-02-021-1/+1
| | | | | | | | | | The adjustments performed by receive_room() are to ensure a line termination can always be written to the read buffer. However, these adjustments are irrelevant to the throttle threshold (because the threshold < buffer limit). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* n_tty: Fix throttle for canon lines > 3967 charsPeter Hurley2015-02-021-0/+5
| | | | | | | | | | | | | The tty driver will be mistakenly throttled if a line termination has not been received, and the line exceeds 3967 chars. Thus, it is possible for the driver to stop sending when it has not yet sent the newline. This does not apply to the pty driver. Don't throttle until at least one line termination has been received. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* n_tty: Eliminate receive_room() from consumer/exclusive pathsPeter Hurley2015-02-021-11/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The input worker never reschedules itself; it only processes input until either there is no more input or the read buffer is full. So the reader is responsible for restarting the input worker only if the read buffer was previously full (no_room == 1) _and_ space is now available to process more input because the reader has consumed data from the read buffer. However, computing the actual space available is not required to determine if the reader has consumed data from the read buffer. This condition is evaluated in 5 situations, each of which the space avail is already known: 1. n_tty_flush_buffer() - the read buffer is empty; kick the worker 2. n_tty_set_termios() - no data has been consumed; do not kick the worker (although it may have kicked the reader so data _will be_ consumed) 3. n_tty_check_unthrottle - avail space > 3968; kick the worker 4. n_tty_read, before leaving - only kick the worker if the reader has moved the tail. This prevents unnecessarily kicking the worker when timeout-style reading is used. 5. n_tty_read, before sleeping - although it is possible for the read buffer to be full and input_available_p() to be false, this can only happen when the input worker is racing the reader, in which case the reader will have been woken and won't sleep. Rename n_tty_set_room() to n_tty_kick_worker() to reflect what the function actually does. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ARM: dts: exynos4: Add stdout-path propertiesTomasz Figa2015-02-029-0/+15
| | | | | | | | | | This patch adds stdout-path property to chosen nodes of Exynos4 boards to enable use of earlycon feature without the need to hardcode port number in kernel itself. Signed-off-by: Tomasz Figa <t.figa@samsung.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: samsung: Add support for early consoleTomasz Figa2015-02-023-0/+116
| | | | | | | | | | | | | | This patch adds support for early console initialized from device tree and kernel command line to all variants of Samsung serial driver. Signed-off-by: Tomasz Figa <t.figa@samsung.com> [mszyprow: added support for command line based initialization, fixed comments, added documentation] Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com> Tested-by: Alim Akhtar <alim.akhtar@samsung.com> Tested-by: Chanwoo Choi <cw00.choi@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: sh-sci: Fix R-Car SCIF and HSCIF overrun handlingHisashi Nakamura2015-02-021-1/+13
| | | | | | | | | | When fifo overrun happened, the interrupt status refers to SCLSR register in R-Car SCIF and HSCIF. Thus, overrun handling takes SCLSR register into account. Signed-off-by: Hisashi Nakamura <hisashi.nakamura.ak@renesas.com> Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: sh-sci: Use dev_dbg() to log an error messageYoshihiro Kaneko2015-02-021-1/+1
| | | | | | | | | | | | Since the driver cannot return from overrun error if characters are output during overrun process, use dev_dbg() instead of dev_notice() to log the error message of overrun in syslog. Based on a patch by Hisashi Nakamura. Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com> Acked-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: 8250_dma: don't bother DMA with small transfersAndy Shevchenko2015-02-021-0/+4
| | | | | | | | If we would like to send amount of data less than FIFO size we better would do this via PIO mode. Otherwise the overhead could be significant. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: 8250_core: remove redundant else keywordAndy Shevchenko2015-02-021-2/+4
| | | | | | | | Since we return in the first branch the second one doesn't require an additional else keyword. The patch removes it. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sh-sci: extend PM methodsSergei Shtylyov2015-02-021-6/+3
| | | | | | | | | | | | | In order to make it possible to restore from hibernation not only in Linux but also in e.g. U-Boot, we have to use sci_{suspend|remove}() for the PM {freeze| thaw|restore}() methods. It's handy to achieve this by using SIMPLE_DEV_PM_OPS() macro, however we have to annotate sci_{suspend|remove}() with '__maybe_unused' in order to avoid compilation warnings when CONFIG_PM_SLEEP is undefined. Based on orignal patch by Mikhail Ulyanov <mikhail.ulyanov@cogentembedded.com>. Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* pty: Fix overlimit memory usePeter Hurley2015-02-021-14/+3
| | | | | | | | | | The pty_space() computation is broken; the space already consumed in the tty buffer is not accounted for. Use tty_buffer_set_limit(), which enforces the limit automatically. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: xuartps: Fix RX hang, and TX corruption in termios callNathan Rossi2015-02-021-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The implementation of flushing the RX FIFO breaks in a number of cases, it is impossible to ensure an complete flush of the RX FIFO due to the hardware not allowing the use of the FIFOs when the receiver is disabled (Reading from the FIFO register does not remove it from the FIFO when the RX_EN=0 or RX_DIS=1). Additionally during an initial set_termios call where RX_DIS=1 causes a hang waiting forever for the RX FIFO to empty. On top of this the FIFO will be cleared by the use of the RXRST bits on the Control Register, making the RX flush pointless (as it does not preserve the data read anyway). Due to the TXRST the TX FIFO and transmitter can be interrupted during frame trasmission, causing corruption and additionally data lost in the FIFO. Most other serial drivers do not flush or clear the FIFOs during a termios configuration change and as such do not have issues with corruption. For this UART controller is it required that the TXRST/RXRST bit be flagged during the change, this means that the data in the FIFO will be dropped when changing configuration. In order to prevent data loss and corruption of the transmitted data, wait until the TX FIFO is empty before changing the configuration. The performance of this may cause the set_termios call to take a longer amount of time especially on lower baud rates, however it is comparable to the same performance hit that a console_write call costs. Signed-off-by: Nathan Rossi <nathan.rossi@xilinx.com> Acked-by: Anirudha Sarangi <anirudh@xilinx.com> Acked-by: Harini Katakam <harinik@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty/isicom: fix big-endian compile warningArnd Bergmann2015-02-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Building an arm allmodconfig kernel triggers a lengthy but harmless warning in the isicom driver: drvers/tty/isicom.c: In function 'isicom_send_break': uapi/linux/swab.h:13:15: warning: integer overflow in expression [-Woverflow] (((__u16)(x) & (__u16)0x00ffU) << 8) | \ ^ uapi/linux/swab.h:107:2: note: in expansion of macro '___constant_swab16' ___constant_swab16(x) : \ ^ uapi/linux/byteorder/big_endian.h:34:43: note: in expansion of macro '__swab16' #define __cpu_to_le16(x) ((__force __le16)__swab16((x))) ^ linux/byteorder/generic.h:89:21: note: in expansion of macro '__cpu_to_le16' #define cpu_to_le16 __cpu_to_le16 ^ include/asm/io.h:270:6: note: in expansion of macro 'cpu_to_le16' cpu_to_le16(v),__io(p)); }) ^ drivers/tty/isicom.c:1058:2: note: in expansion of macro 'outw' outw((length & 0xff00), base); ^ Apparently, the problem is related to the fact that the value 0xff00, when used as a 16-bit number, is negative and passed into bitwise operands of the generic byte swapping code. Marking the input argument as unsigned in both technically correct and avoids the warning. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mxs-auart: Remove unneeded zeroing of 'ret'Fabio Estevam2015-02-021-1/+1
| | | | | | | | | | | | There is no need to explicitly zero the 'ret' variable as it is properly initialized in a few lines below as: ret = serial_mxs_probe_dt(s, pdev); Remove the unneeded zeroing of 'ret'. Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mxs-auart: Check for platform_get_irq() errorFabio Estevam2015-02-021-0/+3
| | | | | | | | We should check whether platform_get_irq() failed, and in the case of error this needs to be propagated. Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mxs-auart: Remove irq from private structureFabio Estevam2015-02-021-6/+4
| | | | | | | | | | | | | The irq number is only used inside the probe function, so there is no need to keep it in the private mxs_auart_port structure. Use a local 'irq' variable for storing the irq number instead. Also make its type of 'int' as platform_get_irq() may fail and return a negative number. Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty/serial: digicolor: remove sysrq referenceBaruch Siach2015-02-021-4/+1
| | | | | | | | | | | | | | | The Digicolor USART hardware does not support detecting the BREAK condition. This means that we can't support sysrq on this hardware. Remove all reference to sysrq from the code. This also fixes build when sysrq is disabled: drivers/tty/serial/digicolor-usart.c: In function 'digicolor_uart_console_write': drivers/tty/serial/digicolor-usart.c:407:33: error: 'struct uart_port' has no member named 'sysrq' Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: 8250_pnp: Enable PNP_CONSOLE for console portsPeter Hurley2015-02-021-1/+7
| | | | | | | | | | | | | | | | When the kernel command line parameter, no_console_suspend, is used, the console should continue to output console messages during and after system suspend. For a serial console, the serial core ensures that the device is not shutdown when no_console_suspend is specified. However, the default operation of the pnp bus will disable and suspend the device and no further output occurs. When registering the 8250 port, if the serial device is a console set the PNP_CONSOLE capability, which prevents device power-off if consoles are not suspending. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* PNP: Allow console to override ACPI device sleepPeter Hurley2015-02-022-3/+11
| | | | | | | | | | | | | If the serial console is an ACPI PNP device, the PNP bus always powers down the device at system suspend, even though the no_console_suspend command line parameter is specified (eg., when debugging suspend/resume). Add PNP_CONSOLE capability, which when set, prevents calling both the ->disable() and ->suspend() PNP protocol methods if console suspend is disabled. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: serial: msm_serial: Remove console unregistration from driver exit.Pramod Gurav2015-02-021-3/+0
| | | | | | | | | | unregister_console() will be called from uart_remove_one_port() while removing the platform driver. So not necessary to call it in driver exit path. Signed-off-by: Pramod Gurav <pramod.gurav@smartplayin.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: serial: msm_serial: code cleanup in msm_console_setupPramod Gurav2015-02-021-20/+4
| | | | | | | | | | | | | | | | The change does following: - baud, flow, bits, parity were being overwritten as they were being reinitialized after parsing. Initialize them when they are declared so that user provided setting are not overwritten. - msm_set_baud_rate() is anyway called in uart_set_options when it calls msm_set_termios(). msm_reset() is called when we change the baud rate. Hence doing away with both of these calls. - CR_CMD_PROTECTION_EN and CR_TX_ENABLE settings are done in msm_set_baud_rate. So do away with this here. Signed-off-by: Pramod Gurav <pramod.gurav@smartplayin.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: 8250_pci: remove one useless explicit type conversionHeikki Krogerus2015-02-021-2/+2
| | | | | Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86, mrst: remove Moorestown specific serial driversAndy Shevchenko2015-02-029-1242/+4
| | | | | | | | | | | | | Intel Moorestown platform support was removed few years ago. This is a follow up which removes Moorestown specific code for the serial devices. It includes mrst_max3110 and earlyprintk bits. This was used on SFI (Medfield, Clovertrail) based platforms as well, though new ones use normal serial interface for the console service. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: David Cohen <david.a.cohen@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: imx: Fix imx_flush_buffer()Fabio Estevam2015-02-021-0/+26
| | | | | | | | | | | | | | | When running an userspace program that does a 'tcflush(fd, TCIOFLUSH)' call we still see the last received character in the URXD register afterwards. Clear UCR2_SRST bit so that the UART FIFO is flushed properly. Since UCR2_SRST also resets some UART registers, we need to save and restore some of them. Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Tested-by: Fugang Duan <B38611@freescale.com> Acked-by: Jason Liu <r64343@freecale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: serial: fsl_lpuart: terminate DMA on buffer flushStefan Agner2015-02-021-0/+11
| | | | | | | | | | | | | | | On uart buffer flush, serial core resets the circular buffer. If a DMA transfer is in progress at that time, the callback lpuart_dma_tx_complete will move buffer's tail unconditionally, hence tail moves beyond head. Use the flush_buffer hook to terminate the DMA imeaditely and avoid lpuart_dma_tx_complete being called in this situation. This bug often showed up while shutdown and lead to duplicate serial console output. Signed-off-by: Stefan Agner <stefan@agner.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: fsl-lpuart: disable interrupt when suspendYuan Yao2015-02-021-0/+13
| | | | | | | | | | | For power management support, we should disable TX and TX interrupt so that kernel can prepare for deep sleep. Retain RX and RX interrupt for wakeup the kernel when receive the input character. Signed-off-by: Yuan Yao <yao.yuan@freescale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: fsl_lpuart: update RX timer on successful DMA transferStefan Agner2015-02-021-0/+1
| | | | | | | | | | | | | | | To end a DMA transfer which did not consume a whole buffer (e.g. one character only), a RX timer is used. When lots of data are received the DMA transfer will complete and setup another DMA transfer, which in turn might complete again. In this cases, it is not necessary to abort the DMA transfers using the RX timer. This change pushes the RX timer timeout into the future each time a DMA transfer completed. Aborting the DMA was not very harmful, since the next received character lead to setup of another RX DMA. Signed-off-by: Stefan Agner <stefan@agner.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: fsl_lpuart: move DMA channel request to probeStefan Agner2015-02-021-52/+44
| | | | | | | | | | | Move the DMA channel request to probe to avoid requesting the DMA channel on each opening of the ttyLPx device. This also fixes a potential issue that TX channel is not freed when only RX channel allocation fails. The DMA channels are now handled independently, so one could use UART with DMA only in TX direction for instance. Signed-off-by: Stefan Agner <stefan@agner.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: fsl_lpuart: avoid new transfer while DMA is runningStefan Agner2015-02-021-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the UART is in DMA receive mode (RDMAS set) and one character just arrived while another interrupt is handled (e.g. TX), the RDRF (receiver data register full flag) is set due to the water level of 1. But since the DMA will take care of this character, there is no need to handle it by calling lpuart_prepare_rx. Handling it leads to adding the RX timeout timer twice: [ 74.336698] Kernel BUG at 80053070 [verbose debug info unavailable] [ 74.342999] Internal error: Oops - BUG: 0 [#1] ARM0:00.00 khungtaskd [ 74.347817] Modules linked in: 0 S 0.0 0.0 0:00.00 writeback [ 74.350926] CPU: 0 PID: 0 Comm: swapper Not tainted 3.19.0-rc3-00001-g39d78e2 #1788 [ 74.358617] Hardware name: Freescale Vybrid VF610 (Device Tree)t [ 74.364563] task: 807a7678 ti: 8079c000 task.ti: 8079c000 kblockd [ 74.370002] PC is at add_timer+0x24/0x28.0 0.0 0:00.09 kworker/u2:1 [ 74.373960] LR is at lpuart_int+0x15c/0x3d8 [ 74.378171] pc : [<80053070>] lr : [<802e0d88>] psr: a0010193 [ 74.378171] sp : 8079de10 ip : 8079de20 fp : 8079de1c [ 74.389694] r10: 807d44c0 r9 : 8688c300 r8 : 00000013 [ 74.394943] r7 : 20010193 r6 : 00000000 r5 : 000000a0 r4 : 86997210 [ 74.401498] r3 : ffffa7da r2 : 80817868 r1 : 86997210 r0 : 86997344 [ 74.408052] Flags: NzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel [ 74.415489] Control: 10c5387d Table: 8611c059 DAC: 00000015 [ 74.421265] Process swapper (pid: 0, stack limit = 0x8079c230) ... Solve this by only execute the receiver path (lpuart_prepare_rx) if the DMA receive mode (RDMAS) is not set. Also, make sure the flag is cleared on initialization, in case it has been left set. This can be best reproduced using UART as a serial console, then running top while dd'ing data into the terminal. Signed-off-by: Stefan Agner <stefan@agner.ch> Cc: stable <stable@vger.kernel.org> # 3.14 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: fsl_lpuart: delete timer on shutdownStefan Agner2015-02-021-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the serial port gets closed while a RX transfer is in progress, the timer might fire after the serial port shutdown finished. This leads in a NULL pointer dereference: [ 7.508324] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [ 7.516590] pgd = 86348000 [ 7.519445] [00000000] *pgd=86179831, *pte=00000000, *ppte=00000000 [ 7.526145] Internal error: Oops: 17 [#1] ARM [ 7.530611] Modules linked in: [ 7.533876] CPU: 0 PID: 123 Comm: systemd Not tainted 3.19.0-rc3-00004-g5b11ea7 #1778 [ 7.541827] Hardware name: Freescale Vybrid VF610 (Device Tree) [ 7.547862] task: 861c3400 ti: 86ac8000 task.ti: 86ac8000 [ 7.553392] PC is at lpuart_timer_func+0x24/0xf8 [ 7.558127] LR is at lpuart_timer_func+0x20/0xf8 [ 7.562857] pc : [<802df99c>] lr : [<802df998>] psr: 600b0113 [ 7.562857] sp : 86ac9b90 ip : 86ac9b90 fp : 86ac9bbc [ 7.574467] r10: 80817180 r9 : 80817b98 r8 : 80817998 [ 7.579803] r7 : 807acee0 r6 : 86989000 r5 : 00000100 r4 : 86997210 [ 7.586444] r3 : 86ac8000 r2 : 86ac9bc0 r1 : 86997210 r0 : 00000000 [ 7.593085] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user [ 7.600341] Control: 10c5387d Table: 86348059 DAC: 00000015 [ 7.606203] Process systemd (pid: 123, stack limit = 0x86ac8230) Setup the timer on UART startup which allows to delete the timer unconditionally on shutdown. This also saves the initialization on each transfer. Signed-off-by: Stefan Agner <stefan@agner.ch> Cc: stable <stable@vger.kernel.org> # 3.14 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Prevent untrappable signals from malicious programPeter Hurley2015-02-021-0/+3
| | | | | | | | | | | | | | | | | | Commit 26df6d13406d1a5 ("tty: Add EXTPROC support for LINEMODE") allows a process which has opened a pty master to send _any_ signal to the process group of the pty slave. Although potentially exploitable by a malicious program running a setuid program on a pty slave, it's unknown if this exploit currently exists. Limit to signals actually used. Cc: Theodore Ts'o <tytso@mit.edu> Cc: Howard Chu <hyc@symas.com> Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> Cc: Jiri Slaby <jslaby@suse.cz> Cc: <stable@vger.kernel.org> # 2.6.36+ Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vt: provide notifications on selection changesNicolas Pitre2015-02-021-1/+3
| | | | | | | | | | | | | The vcs device's poll/fasync support relies on the vt notifier to signal changes to the screen content. Notifier invocations were missing for changes that comes through the selection interface though. Fix that. Tested with BRLTTY 5.2. Signed-off-by: Nicolas Pitre <nico@linaro.org> Cc: Dave Mielke <dave@mielke.cc> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vt_buffer: drop console buffer copying optimisationsDave Airlie2015-02-021-4/+0
| | | | | | | | | | | | | | | | | | | These two copy to/from VGA memory, however on the Silicon Motion SMI750 VGA card on a 64-bit system cause console corruption. This is due to the hw being buggy and not handling a 64-bit transaction correctly. We could try and create a 32-bit version of these routines, but I'm not sure the optimisation is worth much today. Fixes https://bugzilla.redhat.com/show_bug.cgi?id=1132826 Tested-by: Huawei engineering. Signed-off-by: Dave Airlie <airlied@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge 3.19-rc5 into tty-nextGreg Kroah-Hartman2015-01-19613-4336/+6256
|\ | | | | | | | | | | We want those tty fixes in that release in this branch as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * Linux 3.19-rc5v3.19-rc5Linus Torvalds2015-01-181-1/+1
| |
| * Merge tag 'armsoc-for-linus' of ↵Linus Torvalds2015-01-1832-80/+272
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc Pull ARM SoC fixes from Olof Johansson: "We've been sitting on our fixes branch for a while, so this batch is unfortunately on the large side. A lot of these are tweaks and fixes to device trees, fixing various bugs around clocks, reg ranges, etc. There's also a few defconfig updates (which are on the late side, no more of those). All in all the diffstat is bigger than ideal at this time, but nothing in here seems particularly risky" * tag 'armsoc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (31 commits) reset: sunxi: fix spinlock initialization ARM: dts: disable CCI on exynos5420 based arndale-octa drivers: bus: check cci device tree node status ARM: rockchip: disable jtag/sdmmc autoswitching on rk3288 ARM: nomadik: fix up leftover device tree pins ARM: at91: board-dt-sama5: add phy_fixup to override NAND_Tree ARM: at91/dt: sam9263: Add missing clocks to lcdc node ARM: at91: sama5d3: dt: correct the sound route ARM: at91/dt: sama5d4: fix the timer reg length ARM: exynos_defconfig: Enable LM90 driver ARM: exynos_defconfig: Enable options for display panel support arm: dts: Use pmu_system_controller phandle for dp phy ARM: shmobile: sh73a0 legacy: Set .control_parent for all irqpin instances ARM: dts: berlin: correct BG2Q's SM GPIO location. ARM: dts: berlin: add broken-cd and set bus width for eMMC in Marvell DMP DT ARM: dts: berlin: fix io clk and add missing core clk for BG2Q sdhci2 host ARM: dts: Revert disabling of smc91x for n900 ARM: dts: imx51-babbage: Fix ULPI PHY reset modelling ARM: dts: dra7-evm: fix qspi device tree partition size ARM: omap2plus_defconfig: use CONFIG_CPUFREQ_DT ...
| | * Merge tag 'samsung-fixes-3.19' of ↵Olof Johansson2015-01-173-4/+20
| | |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung into fixes Merge "Samsung fixes for v3.19" from Kukjin Kim: Samsung fixes for v3.19 - exynos_defconfig: enable LM90 driver and display panel support - HWMON - SENSORS_LM90 - Direct Rendering Manager (DRM) - DRM bridge registration and lookup framework - Parade ps8622/ps8625 eDP/LVDS bridge - NXP ptn3460 eDP/LVDS bridge - Exynos Fully Interactive Mobile Display controller (FIMD) - Panel registration and lookup framework - Simple panels - Backlight & LCD device support - use pmu_system_controller phandle for dp phy : DP PHY requires pmu_system_controller to handle PMU reg. now * tag 'samsung-fixes-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung: ARM: exynos_defconfig: Enable LM90 driver ARM: exynos_defconfig: Enable options for display panel support arm: dts: Use pmu_system_controller phandle for dp phy Signed-off-by: Olof Johansson <olof@lixom.net>
| | | * ARM: exynos_defconfig: Enable LM90 driverAndreas Faerber2015-01-121-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | multi_v7_defconfig has it as Y already, so build it in here, too, for consistency, and therefore build in HWMON as well. Signed-off-by: Andreas Faerber <afaerber@suse.de> Reviewed-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk> Signed-off-by: Kukjin Kim <kgene@kernel.org>
| | | * ARM: exynos_defconfig: Enable options for display panel supportJavier Martinez Canillas2015-01-121-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many Exynos devices have a display panel. Most of them just have a simple panel while others have more complex configurations that requires an embedded DisplayPort (eDP) to LVDS bridges. This patch enables the following features to be built in the kernel image to support both setups: - Direct Rendering Manager (DRM) - DRM bridge registration and lookup framework - Parade ps8622/ps8625 eDP/LVDS bridge - NXP ptn3460 eDP/LVDS bridge - Exynos Fully Interactive Mobile Display controller (FIMD) - Panel registration and lookup framework - Simple panels - Backlight & LCD device support Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk> Tested-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Kukjin Kim <kgene@kernel.org>
| | | * arm: dts: Use pmu_system_controller phandle for dp phyVivek Gautam2015-01-082-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | DP PHY now require pmu-system-controller to handle PMU register to control PHY's power isolation. Adding the same to dp-phy node. Signed-off-by: Vivek Gautam <gautam.vivek@samsung.com> Reviewed-by: Jingoo Han <jg1.han@samsung.com> Tested-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk> Signed-off-by: Kukjin Kim <kgene@kernel.org>
| | * | reset: sunxi: fix spinlock initializationTyler Baker2015-01-171-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Call spin_lock_init() before the spinlocks are used, both in early init and probe functions preventing a lockdep splat. I have been observing lockdep complaining [1] during boot on my a80 optimus [2] when CONFIG_PROVE_LOCKING has been enabled. This patch resolves the splat, and has been tested on a few other sunxi platforms without issue. [1] http://storage.kernelci.org/next/next-20150107/arm-multi_v7_defconfig+CONFIG_PROVE_LOCKING=y/lab-tbaker/boot-sun9i-a80-optimus.html [2] http://kernelci.org/boot/?a80-optimus Signed-off-by: Tyler Baker <tyler.baker@linaro.org> Cc: <stable@vger.kernel.org> Acked-by: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Olof Johansson <olof@lixom.net>
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