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2015-10-17serial: atmel: fix compiler warning on address castAndre Przywara1-1/+1
Turning on KVM and LPAE support on top of a multi_v7_defconfig will produce a compiler warning in the Atmel serial driver: drivers/tty/serial/atmel_serial.c: In function 'atmel_verify_port': drivers/tty/serial/atmel_serial.c:2299:6: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] if ((void *)port->mapbase != ser->iomem_base) ^ Fix that by using the cast on the right hand side instead, as similar code already does in other drivers. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-15n_tracesink: stop including <asm-generic/bug>Christoph Hellwig1-1/+1
<asm-generic/bug> contains the default implementation of BUG() and friends, which architectures may decide to use. The proper way to get them is <linux/bug.h>, so use that. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2015-10-15n_tracerouter: stop including <asm-generic/bug>Christoph Hellwig1-1/+1
<asm-generic/bug> contains the default implementation of BUG() and friends, which architectures may decide to use. The proper way to get them is <linux/bug.h>, so use that. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2015-10-12Merge 4.3-rc5 into tty-nextGreg Kroah-Hartman6-28/+79
We want the tty fixes and reverts in here as well so that people can properly test and use it. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04drivers/tty: require read access for controlling terminalJann Horn1-4/+27
This is mostly a hardening fix, given that write-only access to other users' ttys is usually only given through setgid tty executables. Signed-off-by: Jann Horn <jann@thejh.net> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: 8250: add uart_config entry for PORT_RT2880Mans Rullgard1-0/+8
This adds an entry to the uart_config table for PORT_RT2880 enabling rx/tx FIFOs. The UART is actually a Palmchip BK-3103 which is found in several devices from Alchemy/RMI, Ralink, and Sigma Designs. Signed-off-by: Mans Rullgard <mans@mansr.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04tty: serial: msm: Remove 115.2 Kbps maximum baud rate limitationIvan T. Ivanov1-3/+17
UART controller is capable to perform transfers up to 4 Mbps. Remove artificial 115.2 Kbps limitation. Signed-off-by: Ivan T. Ivanov <ivan.ivanov@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04tty: serial: msm: Add RX DMA supportIvan T. Ivanov2-3/+233
Add receive DMA support for UARTDM type of controllers. Tested on APQ8064, which have UARTDM v1.3 and ADM DMA engine and APQ8016, which have UARTDM v1.4 and BAM DMA engine. Signed-off-by: Ivan T. Ivanov <ivan.ivanov@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04tty: serial: msm: Add TX DMA supportIvan T. Ivanov2-24/+291
Add transmit DMA support for UARTDM type of controllers. Tested on APQ8064, which have UARTDM v1.3 and ADM DMA engine and APQ8016, which have UARTDM v1.4 and BAM DMA engine. Signed-off-by: Ivan T. Ivanov <ivan.ivanov@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04tty: serial: msm: Add msm prefix to all driver functionsIvan T. Ivanov1-21/+21
Make function naming consistent across this driver. Also rename msm_irq to msm_uart_irq. No functional changes. Signed-off-by: Ivan T. Ivanov <ivan.ivanov@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04tty: serial: msm: replaces (1 << x) with BIT(x) macroPramod Gurav1-22/+22
Replaces (1 << x) with BIT(x) macro Signed-off-by: Pramod Gurav <gpramod@codeaurora.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Ivan T. Ivanov <ivan.ivanov@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04tty: serial: msm: Add mask value for UART_DM registersPramod Gurav2-6/+22
The bit masks for RFR_LEVEL1 and STALE_TIMEOUT_MSB values in MR1 and IPR registers respectively are different for UART and UART_DM hardware cores. We have been using UART core mask values for these. Add the same for UART_DM core. There is no bit setting as UART_IPR_RXSTALE_LAST for UART_DM core so do it only for UART core. Signed-off-by: Pramod Gurav <gpramod@codeaurora.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Ivan T. Ivanov <ivan.ivanov@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04sc16is7xx: null ptr checkSean Nyekjaer1-0/+6
If a wrong compatible flag in specified, the of_match_device returning null. Implemented check and if NULL then returning -ENODEV. Signed-off-by: Sean Nyekjaer <sean.nyekjaer@prevas.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: omap: remove warnings about unused functionsEzequiel Garcia1-0/+2
They're used by only if CONFIG_PM is enabled, so enclose them with proper ifdefs. Removes these warnings: drivers/tty/serial/omap-serial.c:202:12: warning: 'serial_omap_get_context_loss_count' defined but not used [-Wunused-function] drivers/tty/serial/omap-serial.c:213:13: warning: 'serial_omap_enable_wakeup' defined but not used [-Wunused-function] Signed-off-by: Guido Martínez <guido@vanguardiasur.com.ar> Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04mpsc: use dma_set_mask insted of dma_supportedChristoph Hellwig1-1/+1
This ensures the dma mask that is supported by the driver is recorded in the device structure. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: 8250_dma: no need to sync RX bufferAndy Shevchenko1-6/+0
RX buffer is allocated from DMA coherent memory. Thus there is no need to call DMA sync API for it. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: 8250: Refactor serial console restore-from-suspendPeter Hurley1-14/+22
Move h/w reinit of serial console restore-from-suspend into standalone helper function. No functional change. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: 8250: Tolerate clock variance for max baud rateJames Hogan1-9/+19
When the UART clock is set slightly under 1.8432MHz, the 8250 driver core doesn't permit the 115200 baud rate since it calculates the maximum frequency to pass to uart_get_baud_rate by simply dividing the uart clock by 16 which yields a value slightly under 115200, even though the frequency is close enough for the UART to operate reliably. Therefore add some tolerance in the calculation of the maximum baud rate. 1% tolerance allows for marginally slower uart clk than nominal without introducing transmission errors. Signed-off-by: James Hogan <james.hogan@imgtec.com> [pjh: Forward-port & refactor original patch; change tolerance to 1%] Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial_core: support native endiannessMax Filippov1-2/+6
There are three natural ways in which devices may be wired to the system: little endian (device receives correctly ordered bits of a word written by little-endian CPU to its register, but big-endian CPU needs to swap bytes of a word before writing it), big endian (same, but with big-endian CPU in more favourable position) and native endian (CPU of either endianness may do word-sized I/O without need for byteswapping). Adding an option for native endianness allows using single kernel command line for boards with native-endian serial ports on bi-endian architectures. This goes in parallel with 'native-endian' DTS attribute. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04tty/serial: st-asc: drop the use of IRQF_NO_SUSPENDSudeep Holla2-3/+2
These drivers doesn't claim the serial device to be wakeup source. Even if it is, it needs to use enable_irq_wake or other related PM wakeup APIs to enable it. This patch removes yet another misuse of IRQF_NO_SUSPEND. Cc: Srinivas Kandagatla <srinivas.kandagatla@gmail.com> Cc: Maxime Coquelin <maxime.coquelin@st.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-arm-kernel@lists.infradead.org Cc: kernel@stlinux.com Cc: linux-serial@vger.kernel.org Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04MIPS: ttyFDC: replace IRQF_NO_SUSPEND with IRQF_COND_SUSPENDSudeep Holla1-2/+2
Since the FD interrupt handler can discern spurious IRQs and it is shared with timer interrupt, use IRQF_COND_SUSPEND instead of IRQF_NO_SUSPEND. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04tty: serial: lpc32xx_hs: fix handling platform_get_irq resultAndrzej Hajda1-3/+4
The function can return negative values. The problem has been detected using proposed semantic patch scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci [1]. [1]: http://permalink.gmane.org/gmane.linux.kernel/2038576 Signed-off-by: Andrzej Hajda <a.hajda@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04tty: serial: cpm_uart: Fix module autoload for OF platform driverLuis de Bethencourt1-0/+1
This platform driver has a OF device ID table but the OF module alias information is not created so module autoloading won't work. Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com> Acked-by: Timur Tabi <timur@tabi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04tty: serial: sprd: Fix module autoload for OF platform driverLuis de Bethencourt1-0/+1
This platform driver has a OF device ID table but the OF module alias information is not created so module autoloading won't work. Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04tty: serial: of_serial: Fix module autoload for OF platform driverLuis de Bethencourt1-0/+1
This platform driver has a OF device ID table but the OF module alias information is not created so module autoloading won't work. Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04tty: serial: apbuart: Fix module autoload for OF platform driverLuis de Bethencourt1-0/+1
This platform driver has a OF device ID table but the OF module alias information is not created so module autoloading won't work. Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: 8250: simplify ralink/alchemy register remap selectionMans Rullgard2-6/+7
Some SoCs, including Ralink/Mediatek and Alchemy Au1xxx, have a 16550-like UART with a non-standard register layout. These are supported by a simple mapping table in 8250_port.c Rather than list every SoC type using this access mode in the ifdefs there, allow selecting the SERIAL_8250_RT288X Kconfig option with any system and default it to y for the known cases needing it. The help text is reworded accordingly. This change simplifies adding support for other SoCs also using the same UART. The name of the option is a little misleading, but not knowing the true origin of this UART, it is as good a choice as any. Signed-off-by: Mans Rullgard <mans@mansr.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04tty: fix data race on tty_buffer.commitDmitry Vyukov1-3/+12
Race on buffer data happens when newly committed data is picked up by an old flush work in the following scenario: __tty_buffer_request_room does a plain write of tail->commit, no barriers were executed before that. At this point flush_to_ldisc reads this new value of commit, and reads buffer data, no barriers in between. The committed buffer data is not necessary visible to flush_to_ldisc. Similar bug happens when tty_schedule_flip commits data. Update commit with smp_store_release and read commit with smp_load_acquire, as it is commit that signals data readiness. This is orthogonal to the existing synchronization on tty_buffer.next, which is required to not dismiss a buffer with unconsumed data. The data race was found with KernelThreadSanitizer (KTSAN). Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04tty: fix data race in tty_buffer_flushDmitry Vyukov1-1/+4
tty_buffer_flush frees not acquired buffers. As the result, for example, read of b->size in tty_buffer_free can return garbage value which will lead to a huge buffer hanging in the freelist. This is just the benignest manifestation of freeing of a not acquired object. If the object is passed to kfree, heap can be corrupted. Acquire visibility over the buffer before freeing it. The data race was found with KernelThreadSanitizer (KTSAN). Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04tty: fix data race in flush_to_ldiscDmitry Vyukov1-1/+1
flush_to_ldisc reads port->itty and checks that it is not NULL, concurrently release_tty sets port->itty to NULL. It is possible that flush_to_ldisc loads port->itty once, ensures that it is not NULL, but then reloads it again and uses. The second load can already return NULL, which will cause a crash. Use READ_ONCE to read port->itty. The data race was found with KernelThreadSanitizer (KTSAN). Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04tty: fix stall caused by missing memory barrier in drivers/tty/n_tty.cKosuke Tatsukawa1-10/+5
My colleague ran into a program stall on a x86_64 server, where n_tty_read() was waiting for data even if there was data in the buffer in the pty. kernel stack for the stuck process looks like below. #0 [ffff88303d107b58] __schedule at ffffffff815c4b20 #1 [ffff88303d107bd0] schedule at ffffffff815c513e #2 [ffff88303d107bf0] schedule_timeout at ffffffff815c7818 #3 [ffff88303d107ca0] wait_woken at ffffffff81096bd2 #4 [ffff88303d107ce0] n_tty_read at ffffffff8136fa23 #5 [ffff88303d107dd0] tty_read at ffffffff81368013 #6 [ffff88303d107e20] __vfs_read at ffffffff811a3704 #7 [ffff88303d107ec0] vfs_read at ffffffff811a3a57 #8 [ffff88303d107f00] sys_read at ffffffff811a4306 #9 [ffff88303d107f50] entry_SYSCALL_64_fastpath at ffffffff815c86d7 There seems to be two problems causing this issue. First, in drivers/tty/n_tty.c, __receive_buf() stores the data and updates ldata->commit_head using smp_store_release() and then checks the wait queue using waitqueue_active(). However, since there is no memory barrier, __receive_buf() could return without calling wake_up_interactive_poll(), and at the same time, n_tty_read() could start to wait in wait_woken() as in the following chart. __receive_buf() n_tty_read() ------------------------------------------------------------------------ if (waitqueue_active(&tty->read_wait)) /* Memory operations issued after the RELEASE may be completed before the RELEASE operation has completed */ add_wait_queue(&tty->read_wait, &wait); ... if (!input_available_p(tty, 0)) { smp_store_release(&ldata->commit_head, ldata->read_head); ... timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout); ------------------------------------------------------------------------ The second problem is that n_tty_read() also lacks a memory barrier call and could also cause __receive_buf() to return without calling wake_up_interactive_poll(), and n_tty_read() to wait in wait_woken() as in the chart below. __receive_buf() n_tty_read() ------------------------------------------------------------------------ spin_lock_irqsave(&q->lock, flags); /* from add_wait_queue() */ ... if (!input_available_p(tty, 0)) { /* Memory operations issued after the RELEASE may be completed before the RELEASE operation has completed */ smp_store_release(&ldata->commit_head, ldata->read_head); if (waitqueue_active(&tty->read_wait)) __add_wait_queue(q, wait); spin_unlock_irqrestore(&q->lock,flags); /* from add_wait_queue() */ ... timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout); ------------------------------------------------------------------------ There are also other places in drivers/tty/n_tty.c which have similar calls to waitqueue_active(), so instead of adding many memory barrier calls, this patch simply removes the call to waitqueue_active(), leaving just wake_up*() behind. This fixes both problems because, even though the memory access before or after the spinlocks in both wake_up*() and add_wait_queue() can sneak into the critical section, it cannot go past it and the critical section assures that they will be serialized (please see "INTER-CPU ACQUIRING BARRIER EFFECTS" in Documentation/memory-barriers.txt for a better explanation). Moreover, the resulting code is much simpler. Latency measurement using a ping-pong test over a pty doesn't show any visible performance drop. Signed-off-by: Kosuke Tatsukawa <tatsu@ab.jp.nec.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: atmel: fix error path of probe functionUwe Kleine-König1-1/+1
If atmel_init_gpios fails the port has already been marked as busy (in line 2629), so this must be undone in the error path. This bug was introduced because I created the patch that finally became 722ccf416ac2 ("serial: atmel: fix error handling when mctrl_gpio_init fails") on top of 3.19 which didn't have commit 6fbb9bdf0f3f ("tty/serial: at91: fix error handling in atmel_serial_probe()") yet. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Fixes: 722ccf416ac2 ("serial: atmel: fix error handling when mctrl_gpio_init fails") Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04tty: don't leak cdev in tty_cdev_add()Leon Yu1-2/+7
Commit a3a10ce3429e ("Avoid usb reset crashes by making tty_io cdevs truly dynamic") which mixes using cdev_alloc() and cdev_init() is problematic. Subsequent call to cdev_init() after cdev_alloc() sets kobj release method from cdev_dynamic_release() to cdev_default_release() and thus makes it impossible to free allocated cdev. This patch also consolidates error path of cdev_add() as cdev can also leak here if things went wrong. Signed-off-by: Leon Yu <chianglungyu@gmail.com> Fixes: a3a10ce3429e ("Avoid usb reset crashes by making tty_io cdevs truly dynamic") Acked-by: Richard Watts <rrw@kynesim.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04Revert "serial: imx: remove unbalanced clk_prepare"Fabio Estevam1-6/+14
This reverts commit 9e7b399d6528eac33a6fbfceb2b92af209c3454d. Commit ("9e7b399d6528ea") causes the following warning and sometimes also hangs the system: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at kernel/locking/mutex.c:868 mutex_trylock+0x20c/0x22c() DEBUG_LOCKS_WARN_ON(in_interrupt()) Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.2.0-rc7-next-20150818-00001-g14418a6 #4 Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) Backtrace: [<80012f08>] (dump_backtrace) from [<800130a4>] (show_stack+0x18/0x1c) r6:00000364 r5:00000000 r4:00000000 r3:00000000 [<8001308c>] (show_stack) from [<807902b8>] (dump_stack+0x88/0xa4) [<80790230>] (dump_stack) from [<8002a604>] (warn_slowpath_common+0x80/0xbc) r5:807945c4 r4:80ab3b50 [<8002a584>] (warn_slowpath_common) from [<8002a6e4>] (warn_slowpath_fmt+0x38/0x40) r8:00000000 r7:8131100c r6:8054c3cc r5:8131300c r4:80b0a570 [<8002a6b0>] (warn_slowpath_fmt) from [<807945c4>] (mutex_trylock+0x20c/0x22c) r3:8095d0d8 r2:8095ab28 [<807943b8>] (mutex_trylock) from [<8054c3cc>] (clk_prepare_lock+0x14/0xf4) r7:8131100c r6:be3f0c80 r5:00000037 r4:be3f0c80 [<8054c3b8>] (clk_prepare_lock) from [<8054dbfc>] (clk_prepare+0x18/0x30) r5:00000037 r4:be3f0c80 [<8054dbe4>] (clk_prepare) from [<8036a600>] (imx_console_write+0x30/0x244) r4:812d0bc8 r3:8132b9a4 To reproduce the problem we only need to let the board idle for something like 30 seconds. Tested on a imx6q-sabresd. Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Reviewed-by: Eduardo Valentin <edubezval@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: mctrl_gpio: implement interrupt handlingUwe Kleine-König2-2/+162
This allows to reduce the per-driver boiler plate considerably. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: mctrl-gpio: rename init functionUwe Kleine-König5-7/+8
This is done before adding more functionality to the init function with the existing name. As this new functionality conflicts with stuff drivers are required to implement themselves up to I want to convert them one by one to make reviewing and reverting more easy in case I broke something. Once mctrl_gpio_init is there and all drivers are converted mctrl_gpio_init_noauto can be removed again. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: mxs-auart+imx: allow compile testing on non-Freescale architecturesUwe Kleine-König1-2/+2
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: atmel: allow compile testing on non-atmel architecturesUwe Kleine-König2-8/+8
This commit also fixes compiler warnings and errors seen when building on x86_64. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: imx: also update RX stats in DMA pathLucas Stach1-0/+1
The RX bytecount was only updated in the PIO path and thus the device erroneously reported a value of 0 if DMA is in use. Signed-off-by: Lucas Stach <l.stach@pengutronix.de> Acked-by: Jiada Wang <jiada_wang@mentor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: imx: re-enable DMA support without hardware flow controlLucas Stach1-7/+8
The commit enabling DMA support even if no flow control is present was reverted on the grounds that it uncovered a number of bugs in the code that lead to hanging tty devices and/or missing characters. After tracking down the issues it is clear that those were generic bugs and had nothing to do with flow control being present or not, only that allowing DMA without hardware flow control increased the exposure of that code a lot. Now that those bugs are fixed, it should be safe to re-enable DMA support. Signed-off-by: Lucas Stach <l.stach@pengutronix.de> Acked-by: Jiada Wang <jiada_wang@mentor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: imx: don't use idle condition detect for DMA transfersLucas Stach1-26/+5
The reference manual states that idle condition detect should not be used with DMA transfers, as the ROM SDMA scripts don't check those conditions. The RAM SDMA scripts worked around this, but the change broke compatibility with the ROM scripts. The previous commits fixed the DMA burst sizes, so that the aging timer is now working as described in the reference manual. With this fixed we can remove the hack of using the idle condition detect to stop the DMA transfer if there are no new characters incoming. This should work with both the ROM and RAM SDMA scripts. Signed-off-by: Lucas Stach <l.stach@pengutronix.de> Acked-by: Jiada Wang <jiada_wang@mentor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: imx: configure proper DMA burst sizesLucas Stach1-2/+9
Triggering the DMA engine for every byte is horribly inefficient. Also it doesn't allow to use the aging timer for the RX FIFO as this requires the DMA engine to leave one byte remaining in the FIFO when doing a normal burst transfer. Adjust watermark levels so that the DMA engine can do at least 8 byte burst transfers. This is a conservative value, as the both TX and RX FIFOs are able to contain 32 bytes. Signed-off-by: Lucas Stach <l.stach@pengutronix.de> Acked-by: Jiada Wang <jiada_wang@mentor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: imx: always restart DMA if more data is availableLucas Stach1-14/+11
Simplify the DMA restart logic to always queue up the next transfer immediately if there is at least one more byte available in the FIFO, so that the transfer will finish in a limited time. This way the driver stops to rely on zero length transfers to signal transfers ends. Those will go away when the idle detect DMA requests are disabled. Signed-off-by: Lucas Stach <l.stach@pengutronix.de> Acked-by: Jiada Wang <jiada_wang@mentor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: imx: set up aging timer interrupt as DMA triggerLucas Stach1-9/+22
The DMA transfer is only started once we are sure it will finish in a limited time, i.e. only after we received a RRDY interrupt. In order to allow the watermark level to be raised the aging timer and the corresponding interrupt need to be set up as an additional trigger, so that the transfer is also started if the incoming amount of bytes never reach the watermark. Signed-off-by: Lucas Stach <l.stach@pengutronix.de> Acked-by: Jiada Wang <jiada_wang@mentor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: imx: make setup_ufcr more usefulLucas Stach1-18/+19
This function currently doesn't use its parameter. Change prototype to pass in watermark levels, so we can reuse this function in the DMA setup paths. Also relocate to be near the calling functions. Signed-off-by: Lucas Stach <l.stach@pengutronix.de> Acked-by: Jiada Wang <jiada_wang@mentor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: 8250_dw: don't set UPF_BOOT_AUTOCONF flagHeikki Krogerus1-1/+1
serial8250_register_8250_port adds it to all ports it registers. No need to set it separately. Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: 8250_dw: cleanup dw8250_setup_portHeikki Krogerus1-33/+33
Using the same style of declaring variables as used in the other functions of the driver. Passing uart_port to the function instead of uart_8250_port, as it is the one mostly needed. Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: 8250_dw: cleanup dw8250_idma_filterHeikki Krogerus1-6/+1
Remove the extra return. Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: 8250_dw: rename and comment the fallback dma filterHeikki Krogerus1-5/+10
Adding comment where the purpose of the function is explained. The dma parameters are not used, so removing them, and also moving the assignment of the function to the same place where the other dw8250_data structures members are being set in dw8250_probe. Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: 8250_dw: proper support for UARTs without busy functionalityHeikki Krogerus1-1/+12
If the DW_apb_uart is configured with UART_16550_COMPATIBLE configuration parameter set, then the Busy Functionality is not available. These UARTs will never generate the Busy detect indication interrupt, and therefore don't need handling for it. This creates a small optimization for the DW_apb_uarts configured without the busy functionality, but more importantly, it removes the small but real risk of hitting potential issues caused by busy functionality handling when no busy functionality exist. Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>