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2013-11-07Merge tag 'tty-3.13-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial driver updates from Greg KH: "Here's the big tty/serial driver update for 3.13-rc1. There's some more minor n_tty work here, but nothing like previous kernel releases. Also some new driver ids, driver updates for new hardware, and other small things. All of this has been in linux-next for a while with no issues" * tag 'tty-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (84 commits) serial: omap: fix missing comma serial: sh-sci: Enable the driver on all ARM platforms serial: mfd: Staticize local symbols serial: omap: fix a few checkpatch warnings serial: omap: improve RS-485 performance mrst_max3110: fix unbalanced IRQ issue during resume serial: omap: Add support for optional wake-up serial: sirf: remove duplicate defines tty: xuartps: Fix build error when COMMON_CLK is not set tty: xuartps: Fix build error due to missing forward declaration tty: xuartps: Fix "may be used uninitialized" build warning serial: 8250_pci: add Pericom PCIe Serial board Support (12d8:7952/4/8) - Chip PI7C9X7952/4/8 tty: xuartps: Update copyright information tty: xuartps: Implement suspend/resume callbacks tty: xuartps: Dynamically adjust to input frequency changes tty: xuartps: Updating set_baud_rate() tty: xuartps: Force enable the UART in xuartps_console_write tty: xuartps: support 64 byte FIFO size tty: xuartps: Add polled mode support for xuartps tty: xuartps: Implement BREAK detection, add SYSRQ support ...
2013-10-31serial: omap: fix missing commaPhilippe Proulx
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>, Signed-off-by: Philippe Proulx <philippe.proulx@savoirfairelinux.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-29serial: sh-sci: Enable the driver on all ARM platformsLaurent Pinchart
Renesas ARM platforms are transitioning from single-platform to multi-platform kernels using the new ARCH_SHMOBILE_MULTI. Make the driver available on all ARM platforms to enable it on both ARCH_SHMOBILE and ARCH_SHMOBILE_MULTI, and increase build testing coverage with COMPILE_TEST. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-29serial: mfd: Staticize local symbolsJingoo Han
These local symbols are used only in this file. Fix the following sparse warnings: drivers/tty/serial/mfd.c:296:6: warning: symbol 'hsu_dma_tx' was not declared. Should it be static? drivers/tty/serial/mfd.c:343:6: warning: symbol 'hsu_dma_start_rx_chan' was not declared. Should it be static? drivers/tty/serial/mfd.c:389:6: warning: symbol 'hsu_dma_rx' was not declared. Should it be static? drivers/tty/serial/mfd.c:1186:17: warning: symbol 'serial_hsu_pops' was not declared. Should it be static? Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-29serial: omap: fix a few checkpatch warningsPhilippe Proulx
Signed-off-by: Philippe Proulx <philippe.proulx@savoirfairelinux.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-29serial: omap: improve RS-485 performancePhilippe Proulx
If RS-485 is enabled, make the OMAP UART fire THR interrupts when both TX FIFO and TX shift register are empty instead of polling the equivalent status bit. This removes the burst of interrupt requests seen at every end of transmission. Also: the comment said that the TX FIFO trigger level was set at 16 characters when it's 32 in reality. Signed-off-by: Philippe Proulx <philippe.proulx@savoirfairelinux.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-29mrst_max3110: fix unbalanced IRQ issue during resumeChen, Jie
During resume, a startup will request_irq again, meantime resume function's enable_irq will cause unbalanced IRQ issue. Fix this issue by moving request_irq to probe function. Signed-off-by: David Cohen <david.a.cohen@linux.intel.com> Signed-off-by: Chen, Jie <jie.d.chen@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-29serial: omap: Add support for optional wake-upTony Lindgren
With the recent pinctrl-single changes, omaps can treat wake-up events from deeper idle states as interrupts. There's a separate "io chain" controller on most omaps that stays enabled when the device hits off-idle and the regular interrupt controller is powered off. Let's add support for the optional second interrupt for wake-up events. And then serial-omap can manage the wake-up interrupt from it's runtime PM calls to avoid spurious interrupts during runtime. Note that the wake interrupt is board specific as it uses the UART RX pin, and for omap3, there are six pin options for UART3 RX pin. Also Note that the legacy platform based booting handles the wake-ups in the legacy mux driver and does not need to pass the wake-up interrupt to the driver. And finally, to pass the wake-up interrupt in the dts file, either interrupt-map or the pending interrupts-extended property needs to be passed. It's probably best to use interrupts-extended when it's available. Cc: Felipe Balbi <balbi@ti.com> Cc: Kevin Hilman <khilman@linaro.org> Cc: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Felipe Balbi <balbi@ti.com> Reviewed-by: Roger Quadros <rogerq@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-29serial: sirf: remove duplicate definesMichael Opdenacker
This patch removes duplicate defines in drivers/tty/serial/sirfsoc_uart.h Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-29tty: xuartps: Fix build error when COMMON_CLK is not setSoren Brinkmann
Clock notifiers are only available when CONFIG_COMMON_CLK is enabled. Hence all notifier related code has to be protected by corresponsing ifdefs. Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-29tty: xuartps: Fix build error due to missing forward declarationSoren Brinkmann
If CONFIG_PM_SLEEP is enabled and CONFIG_SERIAL_XILINX_PS_UART_CONSOLE is not, a forward declaration of the uart_driver struct is not included, leading to a build error due to an undeclared variable. Fixing this by moving the definition of the struct uart_driver before the definition of the suspend/resume callbacks. Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-29tty: xuartps: Fix "may be used uninitialized" build warningSoren Brinkmann
Initialize varibles for which a 'may be used uninitalized' warning is issued. Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19serial: 8250_pci: add Pericom PCIe Serial board Support (12d8:7952/4/8) - ↵Angelo Butti
Chip PI7C9X7952/4/8 Signed-off-by: Angelo Butti <buttiangelo@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19tty: xuartps: Update copyright informationSoren Brinkmann
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19tty: xuartps: Implement suspend/resume callbacksSoren Brinkmann
Implement suspend and resume callbacks in order to support system suspend/hibernation. Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19tty: xuartps: Dynamically adjust to input frequency changesSoren Brinkmann
Add a clock notifier to dynamically handle frequency changes of the input clock by reprogramming the UART in order to keep the baud rate constant. Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19tty: xuartps: Updating set_baud_rate()Soren Brinkmann
The original algorithm to find the best baud rate dividers does not necessarily find the best set of dividers. And in the worst case may even write illegal values to the hardware. The new function should make better use of the hardware capabilities and be able to provide valid settings for a wider range of baud rates and also input clocks. Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19tty: xuartps: Force enable the UART in xuartps_console_writeLars-Peter Clausen
It is possible that under certain circumstances xuartps_console_write is entered while the UART disabled. When this happens the code will busy loop in xuartps_console_putchar, since the character is never written and the TXEMPTY flag is never set. The result is a system lockup. This patch force enables the UART for the duration of xuartps_console_write to avoid this. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: John Linn <john.linn@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19tty: xuartps: support 64 byte FIFO sizeSuneel
Changes to use the 64 byte FIFO depth and fix the issue by clearing the txempty interrupt in isr status for tx after filling in data in start_tx function Signed-off-by: Suneel Garapati <suneelg@xilinx.com> Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19tty: xuartps: Add polled mode support for xuartpsVlad Lungu
This allows KDB/KGDB to run. Signed-off-by: Vlad Lungu <vlad.lungu@windriver.com> Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19tty: xuartps: Implement BREAK detection, add SYSRQ supportVlad Lungu
The Cadence UART does not do break detection, even if the datasheet says it does. This patch adds break detection in software (tested in 8N1 mode only) and enables SYSRQ, allowing for Break-g to enter KDB and all the other goodies. Signed-off-by: Vlad Lungu <vlad.lungu@windriver.com> Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19tty: xuartps: Use devm_kzallocSoren Brinkmann
Use the device managed interface for memory allocation, simplifying error paths. Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19tty: xuartps: Use devm_clk_get()Soren Brinkmann
Use the device managed interface for clocks, simplifying error paths. Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-17tty/serial: at91: add a fallback option to determine uart/usart propertyNicolas Ferre
On older SoC, the "name" field is not filled in the register map. Fix the way to figure out if the serial port is an uart or an usart for these older products (with corresponding properties). Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-17tty/serial: at91: fix uart/usart selection for older productsNicolas Ferre
Since commit 055560b04a8cd063aea916fd083b7aec02c2adb8 (serial: at91: distinguish usart and uart) the older products which do not have a name field in their register map are unable to use their serial output. As the main console output is usually the serial interface (aka DBGU) it is pretty unfortunate. So, instead of failing during probe() we just silently configure the serial peripheral as an uart. It allows us to use these serial outputs. The proper solution is proposed in another patch. Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-17tty/serial: at91: fix uart/usart selection for older productsNicolas Ferre
Since commit 055560b04a8cd063aea916fd083b7aec02c2adb8 (serial: at91: distinguish usart and uart) the older products which do not have a name field in their register map are unable to use their serial output. As the main console output is usually the serial interface (aka DBGU) it is pretty unfortunate. So, instead of failing during probe() we just silently configure the serial peripheral as an uart. It allows us to use these serial outputs. The proper solution is proposed in another patch. Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-17serial: 8250_pci: add support for Fintek 4, 8, and 12 port cardsGreg Kroah-Hartman
This adds support for Fintek's 4, 8, and 12 port PCIE serial cards. Thanks to Fintek for the sample devices, and the spec needed in order to implement this. Cc: Amanda Ying <amanda_ying@fintek.com.tw> Cc: Felix Shih <felix_shih@fintek.com.tw> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16serial: imx: optimization: remove the workqueues for DMAHuang Shijie
I worried that the delay of the sdma_run_channel0() maybe too long for interrupt context, so I added the workqueues for RX/TX DMA. But tested with bluetooth device, I find that the delay of sdma_run_channel0() is about 8us (tested in imx6dl sabreauto board). I think the delay is acceptable. This patch removes the RX/TX workqueues for DMA, it makes the code more clear. Signed-off-by: Huang Shijie <b32955@freescale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16serial: vt8500: add missing bracesRoel Kluin
Due to missing braces on an if statement, in presence of a device_node a port was always assigned -1, regardless of any alias entries in the device tree. Conversely, if device_node was NULL, an unitialized port ended up being used. This patch adds the missing braces, fixing the issues. Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Acked-by: Tony Prisk <linux@prisktech.co.nz> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16serial: imx: use the dmaengine_tx_statusHuang Shijie
Use the dmaengine_tx_status to simplify the code, do not change any logic. Signed-off-by: Huang Shijie <b32955@freescale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16serial: imx: fix the wrong number of scatterlist entries when xmit->head is 0Huang Shijie
When the (xmit->tail > xmit->head) is true and the xmit->head is 0, we only need one DMA scatterlist in actually. Current code uses two DMA scatterlists in this case, this is obviously wrong. This patch fixes it. Signed-off-by: Huang Shijie <b32955@freescale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16serial: imx: check the DMA for imx_tx_emptyHuang Shijie
Assume the following situation: If the DMA is enabled, and the a TX DMA operation is working, But we have not issued the TX DMA operation (or we have issued the TX DMA operation with dma_async_issue_pending(), but the DMA has not started to move the data from the memory to the TXFIFO). At this time, we may get the wrong status of the transmitter when we call the imx_tx_empty. In such situation, only check the USR2_TXDC does not enough for us. This patch checks the DMA's situation, and return 0 when the TX DMA is working. Signed-off-by: Huang Shijie <b32955@freescale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16serial: imx: implement the flush_buffer hookHuang Shijie
The current driver does not implement the flush_buffer hook for uart_ops. When we enable the DMA for the driver, and test it with Bluetooth, we may meet the following bug for TX: [1] User application may call the flush operation at any time. The uart_flush_buffer() calls the uart_circ_clear() to set the xmit->head and xmit->tail with 0. [2] The TX DMA callback can be called at any time too. The dma_tx_call() will update the xmit->tail. If [2] occurs just after the [1], we will get the wrong xmit->tail. This patch implements the flush_buffer hook to fix this issue. Signed-off-by: Huang Shijie <b32955@freescale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16serial: pch_uart: remove reference to .set_wake()Linus Walleij
This callback is gone and not coming back, so will not be supported later. Cc: Johan Hovold <jhovold@gmail.com> Acked-by: Darren Hart <dvhart@linux.intel.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16serial: mpc52xx: remove reference to .set_wake()Linus Walleij
This callback is gone and not coming back, so will not be supported later. Cc: Gerhard Sittig <gsi@denx.de> Cc: Anatolij Gustschin <agust@denx.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16serial: sa1100: delete .set_wake callbackLinus Walleij
This callback is unused by the serial core since pre-git days and is not coming back. Delete it. Enabling wakeup on the SA1100 platforms should be done in the suspend() callback so the platform hook is left in the serial port struct for later enablement. Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16serial: omap: delete .set_wake callbackLinus Walleij
This callback is unused by the serial core since pre-git days and is not coming back. Delete it. Enabling wakeup on the OMAP serial driver is done through other runpaths these days. Cc: Tony Lindgren <tony@atomide.com> Cc: Kevin Hilman <khilman@deeprootsystems.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16tty: Remove unnecessary semicolonsJoe Perches
These aren't necessary after switch and while blocks. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16serial: mrst_max3110: Fix race condition between spi transfersBin Gao
There is a race between termios configuration and xmit that can cause the intel_mid_ssp_spi driver to stall. Serializing spi transactions fixes the problem. Signed-off-by: Bin Gao <bin.gao@intel.com> Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16serial: mrst_max3110: Check the irq number before enable/disabe irq in PM hooksFeng Tang
We should check the validity of the irq number before calling disable_irq() and enable_irq() in the suspend/resume function, as "max->irq == 0" means the irq is not enabled for max3110 device, otherwise it will hurt device whose irq number is really 0. Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16serial8250-em: convert to clk_prepare/unprepareShinya Kuribayashi
Add calls to clk_prepare and unprepare so that EMMA Mobile EV2 can migrate to the common clock framework. Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com> [takashi.yoshii.ze@renesas.com: edited for conflicts] Signed-off-by: Takashi Yoshii <takashi.yoshii.zj@renesas.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Magnus Damm <damm@opensource.se> Signed-off-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-07Revert "serial: i.MX: evaluate linux,stdout-path property"Greg Kroah-Hartman
This reverts commit f7d2c0bbdb7b784cc035cacb7d36b379ba1c3bef, as it causes build errors when the driver is built as a module. Reported-by: Guenter Roeck <linux@roeck-us.net> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Fabio Estevam <fabio.estevam@freescale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-07serial: bfin_uart: remove deprecated IRQF_DISABLEDMichael Opdenacker
This patch proposes to remove the use of the IRQF_DISABLED flag It's a NOOP since 2.6.35 and it will be removed one day. Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-07serial: tegra: remove deprecated IRQF_DISABLEDMichael Opdenacker
This patch proposes to remove the use of the IRQF_DISABLED flag It's a NOOP since 2.6.35 and it will be removed one day. Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-05serial: mxs-auart: set the FIFO size to DMA buffer sizeHector Palacios
When DMA is enabled (with hardware flow control enabled) the FIFO size must be set to the size of the DMA buffer, as this is the size the tty subsystem can use. Signed-off-by: Hector Palacios <hector.palacios@digi.com> Reviewed-by: Marek Vasut <marex@denx.de> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-03serial: Remove unnecessary amba_set_drvdata()Michal Simek
Driver core clears the driver data to NULL after device_release or on probe failure, so just remove it from here. Driver core change: "device-core: Ensure drvdata = NULL when no driver is bound" (sha1: 0998d0631001288a5974afc0b2a5f568bcdecb4d) Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-03serial: 8250_dw: Improve unwritable LCR workaroundTim Kryger
When configured with UART_16550_COMPATIBLE=NO or in versions prior to the introduction of this option, the Designware UART will ignore writes to the LCR if the UART is busy. The current workaround saves a copy of the last written LCR and re-writes it in the ISR for a special interrupt that is raised when a write was ignored. Unfortunately, interrupts are typically disabled prior to performing a sequence of register writes that include the LCR so the point at which the retry occurs is too late. An example is serial8250_do_set_termios() where an ignored LCR write results in the baud divisor not being set and instead a garbage character is sent out the transmitter. Furthermore, since serial_port_out() offers no way to indicate failure, a serious effort must be made to ensure that the LCR is actually updated before returning back to the caller. This is difficult, however, as a UART that was busy during the first attempt is likely to still be busy when a subsequent attempt is made unless some extra action is taken. This updated workaround reads back the LCR after each write to confirm that the new value was accepted by the hardware. Should the hardware ignore a write, the TX/RX FIFOs are cleared and the receive buffer read before attempting to rewrite the LCR out of the hope that doing so will force the UART into an idle state. While this may seem unnecessarily aggressive, writes to the LCR are used to change the baud rate, parity, stop bit, or data length so the data that may be lost is likely not important. Admittedly, this is far from ideal but it seems to be the best that can be done given the hardware limitations. Lastly, the revised workaround doesn't touch the LCR in the ISR, so it avoids the possibility of a "serial8250: too much work for irq" lock up. This problem is rare in real situations but can be reproduced easily by wiring up two UARTs and running the following commands. # stty -F /dev/ttyS1 echo # stty -F /dev/ttyS2 echo # cat /dev/ttyS1 & [1] 375 # echo asdf > /dev/ttyS1 asdf [ 27.700000] serial8250: too much work for irq96 [ 27.700000] serial8250: too much work for irq96 [ 27.710000] serial8250: too much work for irq96 [ 27.710000] serial8250: too much work for irq96 [ 27.720000] serial8250: too much work for irq96 [ 27.720000] serial8250: too much work for irq96 [ 27.730000] serial8250: too much work for irq96 [ 27.730000] serial8250: too much work for irq96 [ 27.740000] serial8250: too much work for irq96 Signed-off-by: Tim Kryger <tim.kryger@linaro.org> Reviewed-by: Matt Porter <matt.porter@linaro.org> Reviewed-by: Markus Mayer <markus.mayer@linaro.org> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-30serial: 8250_pci: clean up printk() callsGreg Kroah-Hartman
Move the printk() calls to to dev_*() instead, to tie into the dynamic debugging infrastructure. Also change some "raw" printk() calls to dev_err() to provide a better error message to userspace so it can properly identify the device and not just have to guess. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-29Merge 3.12-rc3 into tty-nextGreg Kroah-Hartman
We want the tty/serial fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-27serial: 8250_dw: fix broken function callHeikki Krogerus
The stub for dw8250_probe_acpi() is missing an argument. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>