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| * | | | drivers: PL011: add ACPI probing for SBSA UARTGraeme Gregory2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add the necessary driver boilerplate to let the driver be used when the respective ACPI table is discovered by the ACPI subsystem. [Andre: change table name, add MODULE_DEVICE_TABLE entry and improve commit message] Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Graeme Gregory <graeme.gregory@linaro.org> Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: Naresh Bhat <nbhat@cavium.com> Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | drivers: PL011: add support for the ARM SBSA generic UARTAndre Przywara2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ARM Server Base System Architecture[1] document describes a generic UART which is a subset of the PL011 UART. It lacks DMA support, baud rate control and modem status line control, among other things. The idea is to move the UART initialization and setup into the firmware (which does this job today already) and let the kernel just use the UART for sending and receiving characters. We use the recent refactoring to build a new struct uart_ops variable which points to some new functions avoiding access to the missing registers. We reuse as much existing PL011 code as possible. In contrast to the PL011 the SBSA UART does not define any AMBA or PrimeCell relations, so we go with a pretty generic probe function which only uses platform device functions. A DT binding is provided with this patch, ACPI support is added in a separate one. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: Naresh Bhat <nbhat@cavium.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | drivers: PL011: allow to supply fixed option stringAndre Przywara2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The SBSA UART has a fixed baud rate and flow control setting, which cannot be changed or queried by software. Add a vendor specific property to always return fixed values when trying to read the console options. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: Naresh Bhat <nbhat@cavium.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | drivers: PL011: allow avoiding UART enabling/disablingAndre Przywara2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The SBSA UART should not be enabled or disabled (it is always on), and consequently the spec lacks the UART_CR register. Add a vendor specific property to skip disabling or enabling of the UART. This will be used later by the SBSA UART support. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: Naresh Bhat <nbhat@cavium.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | drivers: PL011: move cts_event workaround into separate functionAndre Przywara2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To avoid lines with more than 80 characters and to make the pl011_int() function more readable, move the workaround out into a separate function. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: Naresh Bhat <nbhat@cavium.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | drivers: PL011: replace UART_MIS reading with _RIS & _IMSCAndre Przywara2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The PL011 register UART_MIS is actually a bitwise AND of the UART_RIS and the UART_MISC register. Since the SBSA UART does not include the _MIS register, use the two separate registers to get the same behaviour. Since we are inside the spinlock and we read the _IMSC register only once, there should be no race issue. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: Naresh Bhat <nbhat@cavium.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | drivers: PL011: refactor pl011_probe()Andre Przywara2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the pl011_probe() function is relying on some AMBA IDs and a device tree node to initialize the driver and a port. Both features are not necessarily required for the driver: - we lack AMBA IDs in the ARM SBSA generic UART and - we lack a DT node in ACPI systems. So lets refactor the function to ease later reuse. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: Naresh Bhat <nbhat@cavium.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | drivers: PL011: refactor pl011_set_termios()Andre Przywara2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Split the pl011_set_termios() function into smaller chunks to allow easier reuse later when adding SBSA support. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: Naresh Bhat <nbhat@cavium.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | drivers: PL011: refactor pl011_shutdown()Andre Przywara2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Split the pl011_shutdown() function into smaller chunks to allow easier reuse later when adding SBSA support. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: Naresh Bhat <nbhat@cavium.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | drivers: PL011: refactor pl011_startup()Andre Przywara2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Split the pl011_startup() function into smaller chunks to allow easier reuse later when adding SBSA support. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: Naresh Bhat <nbhat@cavium.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | drivers: PL011: avoid potential unregister_driver callAndre Przywara2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Although we care about not unregistering the driver if there are still ports connected during the .remove callback, we do miss this check in the pl011_probe function. So if the current port allocation fails, but there are other ports already registered, we will kill those. So factor out the port removal into a separate function and use that in the probe function, too. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: Naresh Bhat <nbhat@cavium.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | tty: serial/8250: remove console dependency for mediatekArnd Bergmann2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the mediatek serial port driver is built-in, but serial console is disabled in Kconfig (e.g. when the serial driver itself is a loadable module), we get this build error: drivers/built-in.o: In function `early_mtk8250_setup': undefined reference to `early_serial8250_setup' To avoid that problem, this patch encloses the early_mtk8250_setup function in #ifdef CONFIG_SERIAL_8250_CONSOLE, the same symbol that guards the early_serial8250_setup function. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Eddie Huang <eddie.huang@mediatek.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: samsung: only use earlycon for consoleArnd Bergmann2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A configuration that enables earlycon but not the core console code causes a link error: drivers/built-in.o: In function `setup_earlycon': drivers/tty/serial/earlycon.c:70: undefined reference to `uart_parse_earlycon' That error can be triggered by the newly added samsung earlycon support, which is missing a 'select' statement. As suggested by Peter Hurley, solves the problem by moving the 'select SERIAL_EARLYCON' statement to the samsung console driver option, as it is done by all other console drivers. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: b94ba0328d3b3 ("serial: samsung: Add support for early console") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | tty: remove platform_sysrq_reset_seqArnd Bergmann2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The platform_sysrq_reset_seq code was intended as a way for an embedded platform to provide its own sysrq sequence at compile time. After over two years, nobody has started using it in an upstream kernel, and the platforms that were interested in it have moved on to devicetree, which can be used to configure the sequence without requiring kernel changes. The method is also incompatible with the way that most architectures build support for multiple platforms into a single kernel. Now the code is producing warnings when built with gcc-5.1: drivers/tty/sysrq.c: In function 'sysrq_init': drivers/tty/sysrq.c:959:33: warning: array subscript is above array bounds [-Warray-bounds] key = platform_sysrq_reset_seq[i]; We could fix this, but it seems unlikely that it will ever be used, so let's just remove the code instead. We still have the option to pass the sequence either in DT, using the kernel command line, or using the /sys/module/sysrq/parameters/reset_seq file. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: 154b7a489a ("Input: sysrq - allow specifying alternate reset sequence") ---- v2: moved sysrq_reset_downtime_ms variable to avoid introducing a compile warning when CONFIG_INPUT is disabled Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: mctrl-gpio: drop usages of IS_ERR_OR_NULLUwe Kleine-König2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function mctrl_gpio_init returns failure if the assignment to any member of the gpio array results in an error pointer. So there is no need to check for such error values in the other functions. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | tty: Spelling s/reseved/reserved/Geert Uytterhoeven2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: 8250_omap: provide complete custom startup & shutdown callbacksSebastian Andrzej Siewior2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The currently in-use port->startup and port->shutdown are "okay". The startup part for instance does the tiny omap extra part and invokes serial8250_do_startup() for the remaining pieces. The workflow in serial8250_do_startup() is okay except for the part where UART_RX is read without a check if there is something to read. I tried to workaround it in commit 0aa525d11859 ("tty: serial: 8250_core: read only RX if there is something in the FIFO") but then reverted it later in commit ca8bb4aefb9 ("serial: 8250: Revert "tty: serial: 8250_core: read only RX if there is something in the FIFO""). This is the second attempt to get it to work on older OMAPs without breaking other chips this time Peter Hurley suggested to pull in the few needed lines from serial8250_do_startup() and drop everything else that is not required including making it simpler like using just request_irq() instead the chain handler like it is doing now. So lets try that. Fixes: ca8bb4aefb93 ("serial: 8250: Revert "tty: serial: 8250_core: read only RX if there is something in the FIFO"") Tested-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: tegra: Fix memory leak on DMA setup failureJon Hunter2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the call to dmaengine_slave_config() fails, then the DMA buffer will not be freed/unmapped. Fix this by moving the code that stores the address of the buffer in the tegra_uart_port structure to before the call to dmaengine_slave_config(). Reported-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: sirf: assign console default index if users not set a valid oneQipan Li2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | it seems this is a more typical behaviour from reviewing other console drivers. Signed-off-by: Qipan Li <Qipan.Li@csr.com> Signed-off-by: Barry Song <Baohua.Song@csr.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: sirf: add serial loopback function supportQipan Li2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Qipan Li <Qipan.Li@csr.com> Signed-off-by: Barry Song <Baohua.Song@csr.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: sirf: add uart receive's some error counter and markQipan Li2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | add overrun error's flag mark and parity's counter, we can show the statistic from procfs node. BTW, let the indentation of stick bits configuration look better. Signed-off-by: Qipan Li <Qipan.Li@csr.com> Signed-off-by: Barry Song <Baohua.Song@csr.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: sirf: fix endless loop bug in uart receive taskletQipan Li2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In special condition, when cpu schedule into rx_tmo_process_tl or rx_dma_complete_tl and all the receive dma tasks have done, it will go into endless loop because no dma task cookie status be changed. Signed-off-by: Qipan Li <Qipan.Li@csr.com> Signed-off-by: Barry Song <Baohua.Song@csr.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: sirf: fix the issue that HW flow control doesn't work for BTQipan Li2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | >From HW spec, when rxfifo's data is less than AFC_RX_THD(RX threshhold), RTS signal is active. otherwise, RTS signal is inactive. Crrently the RX threshhold is set as zero, so RTS has no chance to be active. This patch replaces the default 0 by a positive number. Signed-off-by: Qipan Li <Qipan.Li@csr.com> Signed-off-by: Barry Song <Baohua.Song@csr.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial: sirf: enable ATLAS7 USP serial supportQipan Li2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | differentiate difference port types by re-defining the status MARCO or putting HW differences into private data of the related ports. Signed-off-by: Qipan Li <Qipan.Li@csr.com> Signed-off-by: Barry Song <Baohua.Song@csr.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | tty: rocket: fix comment of ROCKET_SPD_HIMasahiro Yamada2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This comment does not reflect the actual code. It should be 57600, not 56000. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | tty/serial: at91: RS485 mode: 0 is valid for delay_rts_after_sendNicolas Ferre2015-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In RS485 mode, we may want to set the delay_rts_after_send value to 0. In the datasheet, the 0 value is said to "disable" the Transmitter Timeguard but this is exactly the expected behavior if we want no delay... Moreover, if the value was set to non-zero value by device-tree or earlier ioctl command, it was impossible to change it back to zero. Reported-by: Sami Pietikäinen <Sami.Pietikainen@wapice.com> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: stable@vger.kernel.org # 3.2+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | serial/amba-pl011: Fix mismerge between v4.1-rc4 and tty-nextDave Martin2015-05-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit 02730d3c053a9af1d402e1c8dc8bbbc5a1340406 (Merge 4.1-rc4 into tty-next), git mismerged some lines, reintroducing a reference to the removed field uart_amba_port.tx_irq_seen. This causes a build failure. This patch removes the mismerged lines, restoring the code to what was in tty-next (which was the intention). Signed-off-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | Merge 4.1-rc4 into tty-nextGreg Kroah-Hartman2015-05-18
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This resolves some tty driver merge issues. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | | vt: Don't check KD_GRAPHICS when binding/unbindingDaniel Vetter2015-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This was introduced in commit 6db4063c5b72b46e9793b0f141a7a3984ac6facf Author: Antonino A. Daplas <adaplas@gmail.com> Date: Mon Jun 26 00:27:12 2006 -0700 [PATCH] VT binding: Add sysfs control to the VT layer with the justification "In addition, if any of the consoles are in KD_GRAPHICS mode, binding and unbinding will not succeed. KD_GRAPHICS mode usually indicates that the underlying console hardware is used for other purposes other than displaying text (ie X). This feature should prevent binding/unbinding from interfering with a graphics application using the VT." I think we should lift this artificial restriction though: - KD_GRAPHICS doesn't get cleaned up automatically, which means it's easy to have terminals stuck in KD_GRAPHICS when hacking around on X. - X doesn't really care, especially with drm where kms already blocks fbdev (and hence fbcon) when there's an active compositor. - This is a root-only interface with a separate .config option and it's possible to hang your machine already anyway if you unload/reload drivers and don't know what you're doing. With this patch i915.ko module reloading works again reliably, something in the recent fedora upgrades broke things. Cc: Antonino A. Daplas <adaplas@gmail.com> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Imre Deak <imre.deak@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Acked-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | | vt: fix console lock vs. kernfs s_active lock orderImre Deak2015-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently there is a lock order problem between the console lock and the kernfs s_active lock of the console driver's bind sysfs entry. When writing to the sysfs entry the lock order is first s_active then console lock, when unregistering the console driver via do_unregister_con_driver() the order is the opposite. See the below bugzilla reference for one instance of a lockdep backtrace. Fix this by unregistering the console driver from a deferred work, where we can safely drop the console lock while unregistering the device and corresponding sysfs entries (which in turn acquire s_active). Note that we have to keep the console driver slot in the registered_con_driver array reserved for the driver that's being unregistered until it's fully removed. Otherwise a concurrent call to do_register_con_driver could try to reuse the same slot and fail when registering the corresponding device with a minor index that's still in use. Note that the referenced bug report contains two dmesg logs with two distinct lockdep reports: [1] is about a locking scenario involving s_active, console_lock and the fb_notifier list lock, while [2] is about a locking scenario involving only s_active and console_lock. In [1] locking fb_notifier triggers the lockdep warning only because of its dependence on console_lock, otherwise case [1] is the same s_active<->console_lock dependency problem fixed by this patch. Before this change we have the following locking scenarios involving the 3 locks: a) via do_unregister_framebuffer()->...->do_unregister_con_driver(): 1. console lock 2. fb_notifier lock 3. s_active lock b) for example via give_up_console()->do_unregister_con_driver(): 1. console lock 2. s_active lock c) via vt_bind()/vt_unbind(): 1. s_active lock 2. console lock Since c) is the console bind sysfs entry's write code path we can't change the locking order there. We can only fix this issue by removing s_active's dependence on the other two locks in a) and b). We can do this only in the vt code which owns the corresponding sysfs entry, so that after the change we have: a) 1. console lock 2. fb_notifier lock b) 1. console lock c) 1. s_active lock 2. console lock d) in the new con_driver_unregister_callback(): 1. s_active lock [1] https://bugs.freedesktop.org/attachment.cgi?id=87716 [2] https://bugs.freedesktop.org/attachment.cgi?id=107602 v2: - get console_lock earlier in con_driver_unregister_callback(), so we protect the following console driver field assignments there - add code coment explaining the reason for deferring the sysfs entry removal - add a third paragraph to the commit message explaining why there are two distinct lockdep reports and that this issue is independent of fb/fbcon. (Peter Hurley) v3: - clarify further the third paragraph v4: - rebased on v4 of patch 1/3 Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | | tty/hvc: remove celleb-only beat driverDaniel Axtens2015-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The beat hvc driver is only used by celleb. celleb has been dropped [1], so drop the drivers. [1] http://patchwork.ozlabs.org/patch/451730/ CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> CC: Jiri Slaby <jslaby@suse.cz> CC: Valentin Rothberg <valentinrothberg@gmail.com> CC: mpe@ellerman.id.au CC: linuxppc-dev@lists.ozlabs.org Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | | drivers/tty/nozomi.c: rename CONFIG_MAGICValentin Rothberg2015-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The CONFIG_ prefix is reserved for Kconfig options in Make and CPP syntax. CONFIG_MAGIC is a file local CPP identifier so change the prefix to apply to Kconfig's naming convention. Signed-off-by: Valentin Rothberg <valentinrothberg@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | | TTY: msm_smd_tty: Remove unused driverStephen Boyd2015-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This code is no longer used now that mach-msm has been removed. Delete it. Cc: David Brown <davidb@codeaurora.org> Cc: Bryan Huntsman <bryanh@codeaurora.org> Cc: Daniel Walker <dwalker@fifo99.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | | vt: add cursor blink interval escape sequenceScot Doyle2015-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add an escape sequence to specify the current console's cursor blink interval. The interval is specified as a number of milliseconds until the next cursor display state toggle, from 50 to 65535. /proc/loadavg did not show a difference with a one msec interval, but the lower bound is set to 50 msecs since slower hardware wasn't tested. Store the interval in the vc_data structure for later access by fbcon, initializing the value to fbcon's current hardcoded value of 200 msecs. Signed-off-by: Scot Doyle <lkml14@scotdoyle.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | | serial: tegra: Correct error handling on DMA setupJon Hunter2015-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Function tegra_uart_dma_channel_allocate() does not check that dma_map_single() mapped the DMA buffer correctly. Add a check for this and appropriate error handling. Furthermore, if dmaengine_slave_config() (called by tegra_uart_dma_channel_allocate()) fails, then memory allocated/mapped is not freed/unmapped. Therefore, call tegra_uart_dma_channel_free() instead of just dma_release_channel() if dmaengine_slave_config() fails. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | | serial: tegra: Correct shutdown of UARTsJon Hunter2015-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are two issues in the shutdown path of the UARTs which are: 1. The function tegra_uart_shutdown() calls tegra_uart_flush_buffer() to stop DMA TX transfers. However, tegra_uart_flush_buffer() is called after the DMA channels have already been freed and so actually does nothing. 2. The function that frees the DMA channels (tegra_uart_dma_channel_free()), unmaps the dma buffer before freeing the DMA channel and does not ensure the DMA has been stopped. Resolve this by fixing the code in tegra_uart_dma_channel_free() to ensure the DMA is stopped, free the DMA channel and then unmap the DMA buffer. Finally, remove the unnecessary call to tegra_uart_flush_buffer(). Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | | serial: tegra: Fix cookie used by TX channelJon Hunter2015-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The DMA cookie for the RX channel is being used by the TX channel. Therefore, fix driver to use the correct DMA cookie for the TX channel. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | | serial: tegra: Use unsigned types for RX and TX byte countsJon Hunter2015-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function tty_insert_flip_string() takes an argument "size" which is of type size_t. This is an unsigned type. Update the count, rx_bytes_requested and tx_bytes_requested in the tegra serial driver to be unsigned integers so that an unsigned type is passed to tty_insert_flip_string(). Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | | serial: tegra: handle race condition on uart rx sideShardar Shariff Md2015-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The tegra serial driver has two paths through which receive data is copied up to the tty layer. These are: 1. DMA completion callback 2. UART RX interrupt A UART RX interrupt occurs for either RX_TIMEOUT (data has been sitting in the Rx FIFO for more than 4 character times without being read because there is not enough data to reach the trigger level), End of Receive Data event (receiver detects that data stops coming in for more than 4 character times) or a receive error. In the RX interrupt path, the following happens ... - All RX DMA transfers are stopped - Any data in the DMA buffer and RX FIFO are copied up to the tty layer. - DMA is restarted/primed for the RX path In the DMA completion callback, the DMA buffer is copied up to the tty layer but there is no check to see if the RX interrupt could have occurred between the DMA interrupt firing the the DMA callback running. Hence, if a RX interrupt was to occur shortly after the DMA completion interrupt, it is possible that the RX interrupt path has already copied the DMA buffer before the DMA callback has been called. Therefore, when the DMA callback is called, if the DMA is already in-progress, then this indicates that the UART RX interrupt has already occurred and there is nothing to do in the DMA callback. This race condition can cause duplicated data to be received. Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com> [jonathanh@nvidia.com: Moved async_tx_ack() call to after check to see if DMA has completed because if the DMA is in progress we do not need to ACK yet. Changed the print from dev_info to dev_debug. Updated changelog to add more commentary on the race condition based upon feedback from author.] Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | | serial: tegra: check the count and read if any from dmaShardar Shariff Md2015-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is only necessary to read data from the dma buffer when the count value is non-zero and hence, tegra_uart_copy_rx_to_tty() so only be called when this is the case. Although, this was being tested for in two places, there is a third place where this was not tested. However, instead of adding another if-statement prior to calling tegra_uart_copy_rx_to_tty(), move the test inside the function. Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com> [jonathanh@nvidia.com: Re-worked patch to move the check for the count value inside the function tegra_uart_copy_rx_to_tty(). Updated changelog with more commentary.] Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | | serial: tegra: Add delay after enabling FIFO modeJon Hunter2015-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For all tegra devices (up to t210), there is a hardware issue that requires software to wait for 3 UART clock periods after enabling the TX fifo, otherwise data could be lost. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | | serial: tegra: Correct delay after TX flushJon Hunter2015-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For all tegra devices (up to t210), there is a hardware issue that requires software to wait for 32 UART clock periods for the flush to propagate otherwise TX data could be post. Add a helper function to wait for N UART clock periods and update delay following FIFO flush to be 32 UART clock cycles. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | | serial: of_serial: do not set port.type twiceMasahiro Yamada2015-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The port.type has already been set by of_platform_serial_setup() called from a few lines above. Setting it to the same value is redundant. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | | serial: 8250: do not copy port.fifosize member twiceMasahiro Yamada2015-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The port.fifosize member has already been copied at 8 lines above. Maybe the compiler optimization can clean it away, but just in case. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | | serial: xuartps: add __init to earlycon write methodMasahiro Yamada2015-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Early console functions are only used during the early boot stage. This change just saves a small amount of memory footprint. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | | serial: 8250: Do nothing if nr_uarts=0Jan Kiszka2015-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When nr_uarts was set to 0 (via config or 8250_core.nr_uarts), we crash early on x86 because serial8250_isa_init_ports dereferences base_ops which remains NULL. In fact, there is nothing to do for all the callers of serial8250_isa_init_ports if there are no uarts. Based on suggestions by Peter Hurley. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | | serial: samsung: Constify platform_device_idKrzysztof Kozlowski2015-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The platform_device_id is not modified by the driver and core uses it as const. Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | | serial: samsung: Staticize local symbolKrzysztof Kozlowski2015-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Staticize symbols not exported and not used outside of file. Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | | serial: mxs: Constify platform_device_idKrzysztof Kozlowski2015-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The platform_device_id is not modified by the driver and core uses it as const. Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | | serial: imx: Constify platform_device_idKrzysztof Kozlowski2015-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The platform_device_id is not modified by the driver and core uses it as const. Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>