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2015-02-02tty/serial: digicolor: remove sysrq referenceBaruch Siach1-4/+1
The Digicolor USART hardware does not support detecting the BREAK condition. This means that we can't support sysrq on this hardware. Remove all reference to sysrq from the code. This also fixes build when sysrq is disabled: drivers/tty/serial/digicolor-usart.c: In function 'digicolor_uart_console_write': drivers/tty/serial/digicolor-usart.c:407:33: error: 'struct uart_port' has no member named 'sysrq' Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02serial: 8250_pnp: Enable PNP_CONSOLE for console portsPeter Hurley1-1/+7
When the kernel command line parameter, no_console_suspend, is used, the console should continue to output console messages during and after system suspend. For a serial console, the serial core ensures that the device is not shutdown when no_console_suspend is specified. However, the default operation of the pnp bus will disable and suspend the device and no further output occurs. When registering the 8250 port, if the serial device is a console set the PNP_CONSOLE capability, which prevents device power-off if consoles are not suspending. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02tty: serial: msm_serial: Remove console unregistration from driver exit.Pramod Gurav1-3/+0
unregister_console() will be called from uart_remove_one_port() while removing the platform driver. So not necessary to call it in driver exit path. Signed-off-by: Pramod Gurav <pramod.gurav@smartplayin.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02tty: serial: msm_serial: code cleanup in msm_console_setupPramod Gurav1-20/+4
The change does following: - baud, flow, bits, parity were being overwritten as they were being reinitialized after parsing. Initialize them when they are declared so that user provided setting are not overwritten. - msm_set_baud_rate() is anyway called in uart_set_options when it calls msm_set_termios(). msm_reset() is called when we change the baud rate. Hence doing away with both of these calls. - CR_CMD_PROTECTION_EN and CR_TX_ENABLE settings are done in msm_set_baud_rate. So do away with this here. Signed-off-by: Pramod Gurav <pramod.gurav@smartplayin.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02serial: 8250_pci: remove one useless explicit type conversionHeikki Krogerus1-2/+2
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02x86, mrst: remove Moorestown specific serial driversAndy Shevchenko4-981/+0
Intel Moorestown platform support was removed few years ago. This is a follow up which removes Moorestown specific code for the serial devices. It includes mrst_max3110 and earlyprintk bits. This was used on SFI (Medfield, Clovertrail) based platforms as well, though new ones use normal serial interface for the console service. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: David Cohen <david.a.cohen@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02serial: imx: Fix imx_flush_buffer()Fabio Estevam1-0/+26
When running an userspace program that does a 'tcflush(fd, TCIOFLUSH)' call we still see the last received character in the URXD register afterwards. Clear UCR2_SRST bit so that the UART FIFO is flushed properly. Since UCR2_SRST also resets some UART registers, we need to save and restore some of them. Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Tested-by: Fugang Duan <B38611@freescale.com> Acked-by: Jason Liu <r64343@freecale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02tty: serial: fsl_lpuart: terminate DMA on buffer flushStefan Agner1-0/+11
On uart buffer flush, serial core resets the circular buffer. If a DMA transfer is in progress at that time, the callback lpuart_dma_tx_complete will move buffer's tail unconditionally, hence tail moves beyond head. Use the flush_buffer hook to terminate the DMA imeaditely and avoid lpuart_dma_tx_complete being called in this situation. This bug often showed up while shutdown and lead to duplicate serial console output. Signed-off-by: Stefan Agner <stefan@agner.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02serial: fsl-lpuart: disable interrupt when suspendYuan Yao1-0/+13
For power management support, we should disable TX and TX interrupt so that kernel can prepare for deep sleep. Retain RX and RX interrupt for wakeup the kernel when receive the input character. Signed-off-by: Yuan Yao <yao.yuan@freescale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02serial: fsl_lpuart: update RX timer on successful DMA transferStefan Agner1-0/+1
To end a DMA transfer which did not consume a whole buffer (e.g. one character only), a RX timer is used. When lots of data are received the DMA transfer will complete and setup another DMA transfer, which in turn might complete again. In this cases, it is not necessary to abort the DMA transfers using the RX timer. This change pushes the RX timer timeout into the future each time a DMA transfer completed. Aborting the DMA was not very harmful, since the next received character lead to setup of another RX DMA. Signed-off-by: Stefan Agner <stefan@agner.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02serial: fsl_lpuart: move DMA channel request to probeStefan Agner1-52/+44
Move the DMA channel request to probe to avoid requesting the DMA channel on each opening of the ttyLPx device. This also fixes a potential issue that TX channel is not freed when only RX channel allocation fails. The DMA channels are now handled independently, so one could use UART with DMA only in TX direction for instance. Signed-off-by: Stefan Agner <stefan@agner.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02serial: fsl_lpuart: avoid new transfer while DMA is runningStefan Agner1-4/+5
When the UART is in DMA receive mode (RDMAS set) and one character just arrived while another interrupt is handled (e.g. TX), the RDRF (receiver data register full flag) is set due to the water level of 1. But since the DMA will take care of this character, there is no need to handle it by calling lpuart_prepare_rx. Handling it leads to adding the RX timeout timer twice: [ 74.336698] Kernel BUG at 80053070 [verbose debug info unavailable] [ 74.342999] Internal error: Oops - BUG: 0 [#1] ARM0:00.00 khungtaskd [ 74.347817] Modules linked in: 0 S 0.0 0.0 0:00.00 writeback [ 74.350926] CPU: 0 PID: 0 Comm: swapper Not tainted 3.19.0-rc3-00001-g39d78e2 #1788 [ 74.358617] Hardware name: Freescale Vybrid VF610 (Device Tree)t [ 74.364563] task: 807a7678 ti: 8079c000 task.ti: 8079c000 kblockd [ 74.370002] PC is at add_timer+0x24/0x28.0 0.0 0:00.09 kworker/u2:1 [ 74.373960] LR is at lpuart_int+0x15c/0x3d8 [ 74.378171] pc : [<80053070>] lr : [<802e0d88>] psr: a0010193 [ 74.378171] sp : 8079de10 ip : 8079de20 fp : 8079de1c [ 74.389694] r10: 807d44c0 r9 : 8688c300 r8 : 00000013 [ 74.394943] r7 : 20010193 r6 : 00000000 r5 : 000000a0 r4 : 86997210 [ 74.401498] r3 : ffffa7da r2 : 80817868 r1 : 86997210 r0 : 86997344 [ 74.408052] Flags: NzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel [ 74.415489] Control: 10c5387d Table: 8611c059 DAC: 00000015 [ 74.421265] Process swapper (pid: 0, stack limit = 0x8079c230) ... Solve this by only execute the receiver path (lpuart_prepare_rx) if the DMA receive mode (RDMAS) is not set. Also, make sure the flag is cleared on initialization, in case it has been left set. This can be best reproduced using UART as a serial console, then running top while dd'ing data into the terminal. Signed-off-by: Stefan Agner <stefan@agner.ch> Cc: stable <stable@vger.kernel.org> # 3.14 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02serial: fsl_lpuart: delete timer on shutdownStefan Agner1-3/+4
If the serial port gets closed while a RX transfer is in progress, the timer might fire after the serial port shutdown finished. This leads in a NULL pointer dereference: [ 7.508324] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [ 7.516590] pgd = 86348000 [ 7.519445] [00000000] *pgd=86179831, *pte=00000000, *ppte=00000000 [ 7.526145] Internal error: Oops: 17 [#1] ARM [ 7.530611] Modules linked in: [ 7.533876] CPU: 0 PID: 123 Comm: systemd Not tainted 3.19.0-rc3-00004-g5b11ea7 #1778 [ 7.541827] Hardware name: Freescale Vybrid VF610 (Device Tree) [ 7.547862] task: 861c3400 ti: 86ac8000 task.ti: 86ac8000 [ 7.553392] PC is at lpuart_timer_func+0x24/0xf8 [ 7.558127] LR is at lpuart_timer_func+0x20/0xf8 [ 7.562857] pc : [<802df99c>] lr : [<802df998>] psr: 600b0113 [ 7.562857] sp : 86ac9b90 ip : 86ac9b90 fp : 86ac9bbc [ 7.574467] r10: 80817180 r9 : 80817b98 r8 : 80817998 [ 7.579803] r7 : 807acee0 r6 : 86989000 r5 : 00000100 r4 : 86997210 [ 7.586444] r3 : 86ac8000 r2 : 86ac9bc0 r1 : 86997210 r0 : 00000000 [ 7.593085] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user [ 7.600341] Control: 10c5387d Table: 86348059 DAC: 00000015 [ 7.606203] Process systemd (pid: 123, stack limit = 0x86ac8230) Setup the timer on UART startup which allows to delete the timer unconditionally on shutdown. This also saves the initialization on each transfer. Signed-off-by: Stefan Agner <stefan@agner.ch> Cc: stable <stable@vger.kernel.org> # 3.14 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02tty: Prevent untrappable signals from malicious programPeter Hurley1-0/+3
Commit 26df6d13406d1a5 ("tty: Add EXTPROC support for LINEMODE") allows a process which has opened a pty master to send _any_ signal to the process group of the pty slave. Although potentially exploitable by a malicious program running a setuid program on a pty slave, it's unknown if this exploit currently exists. Limit to signals actually used. Cc: Theodore Ts'o <tytso@mit.edu> Cc: Howard Chu <hyc@symas.com> Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> Cc: Jiri Slaby <jslaby@suse.cz> Cc: <stable@vger.kernel.org> # 2.6.36+ Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02vt: provide notifications on selection changesNicolas Pitre1-1/+3
The vcs device's poll/fasync support relies on the vt notifier to signal changes to the screen content. Notifier invocations were missing for changes that comes through the selection interface though. Fix that. Tested with BRLTTY 5.2. Signed-off-by: Nicolas Pitre <nico@linaro.org> Cc: Dave Mielke <dave@mielke.cc> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-22s390/hvc_iucv: add simple wildcard matches to the iucv allow filterHendrik Brueckner1-7/+24
Introduce a wildcard character to filter a range of z/VM user IDs with a single filter entry. Only the leading portion up to the wildcard of an filter entry contributes to the match. This reduces the filter size and avoids configuration updates when deploying new terminal server instances. Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-01-19Merge 3.19-rc5 into tty-nextGreg Kroah-Hartman5-35/+70
We want those tty fixes in that release in this branch as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09vt: fix locking around vt_bind/vt_unbindImre Deak1-6/+5
Currently vt_bind and vt_unbind access at least the con_driver object and registered_con_driver array without holding the console lock. Fix this by locking around the whole function in each case. Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09vt: fix check for system/busy console drivers when unregistering themImre Deak1-2/+1
The default console driver (conswitchp) and busy drivers bound to a console (as reported by con_is_bound()) shouldn't be unregistered. System console drivers (without the CON_DRIVER_FLAG_MODULE flag) can be unregistered, provided they are neither default nor busy. The current code checks for the CON_DRIVER_FLAG_INIT flag but this doesn't make sense: this flag is set for a driver whenever its associated console's con_startup() function is called, which first happens when the console driver is registered (so before the console gets bound) and gets cleared when the console gets unbound. The purpose of this flag is to show if we need to call con_startup() on a console before we use it. Based on the above, do_unregister_con_driver() in its current form will allow unregistering a console driver only if it was never bound, but will refuse to unregister one that was bound and later unbound. Fix this by dropping the CON_DRIVER_FLAG_INIT check, allowing unregistering of any console driver provided that it's not the default one and it's not busy. v2: - reword the third paragraph to clarify how the fix works (Peter Hurley) v3: - unchanged v4: - Allow unregistering a system console driver too, needed by i915 to unregister vgacon. Update commit description accordingly. (Daniel) 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>
2015-01-09TTY: fix misspelling of current function in stringJulia Lawall1-2/+2
Replace a misspelled function name by %s and then __func__. This was done using Coccinelle, including the use of Levenshtein distance, as proposed by Rasmus Villemoes. Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09TTY: fix misspelling of current function in stringJulia Lawall1-1/+1
Replace the last argument of serial_paranoia_check by the actual function name. This was done using Coccinelle, including the use of Levenshtein distance, as proposed by Rasmus Villemoes. Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09serial: 8250_early: optimize early 8250 uartVineet Gupta1-2/+5
In early 8250, IER is already zero so no point in writing this - twice per line This helped improve the SystemC model based ARC OSCI platform Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.cz> Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: Rob Herring <robh@kernel.org> Cc: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09tty: 8250: Add 64byte UART support for FSL platformsVijay Rai1-1/+22
Some of FSL SoCs like T1040 has new version of UART controller which can support 64byte FiFo. To enable 64 byte support, following needs to be done: -FCR[EN64] needs to be programmed to 1 to enable it. -Also, when FCR[EN64]==1, RTL bits to be used as below to define various Receive Trigger Levels: -FCR[RTL] = 00 1 byte -FCR[RTL] = 01 16 bytes -FCR[RTL] = 10 32 bytes -FCR[RTL] = 11 56 bytes -tx_loadsz is set to 63-bytes instead of 64-bytes to implement workaround of errata A-008006 which states that tx_loadsz should be configured less than Maximum supported fifo bytes Signed-off-by: Vijay Rai <vijay.rai@freescale.com> Signed-off-by: Priyanka Jain <Priyanka.Jain@freescale.com> Signed-off-by: Poonam Aggrwal <poonam.aggrwal@freescale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09serial: driver for Conexant Digicolor USARTBaruch Siach3-0/+579
Signed-off-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09serial: imx: ignore framing errors when IGNPAR is set.Eric Nelson1-1/+1
When IGNPAR is set in termios->c_iflag, characters with framing errors should be ignored. Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09serial: imx: preserve characters with parity or framing errorsEric Nelson1-1/+1
If IGNPAR/INPCK are clear in termios->c_iflag, characters received with parity or framing errors should be preserved and passed to the upper layers of the tty stack. Specifically, the decision of whether to set the character value to zero should be made by n_tty.c/n_tty_receive_parity_error(). Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09serial: altera-uart: fix NULL device in log messageLey Foon Tan1-0/+1
Add device pointer to port->dev. Before: "(NULL device *): ttyAL0 at MMIO 0x2020 (irq = 6, base_baud = 3125000) is a Altera UART" After: "altera_uart 2020.serial: ttyAL0 at MMIO 0x2020 (irq = 6, base_baud = 3125000) is a Altera UART" Signed-off-by: Ley Foon Tan <lftan@altera.com> Acked-by: Tobias Klauser <tklauser@distanz.ch> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09serial: altera-juart: fix NULL device in log messageLey Foon Tan1-0/+1
Add device pointer to port->dev. Before: "(NULL device *): ttyJ0 at MMIO 0x1008 (irq = 2, base_baud = 0) is a Altera JTAG UART" After: "altera_jtaguart 1008.serial: ttyJ0 at MMIO 0x1008 (irq = 2, base_baud = 0) is a Altera JTAG UART" Signed-off-by: Ley Foon Tan <lftan@altera.com> Acked-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09serial: samsung: add DMA support for RXRobert Baldyga2-3/+231
Add RX DMA transfers support for samsung serial driver. It's enabled when DMA controller for RX channel is specified in device-tree. DMA transactions are started when number of bytes in RX FIFO reaches trigger level, otherwise PIO mode is used. DMA transfer size is always PAGE_SIZE which can cause large latency when smaller data amount is transferred, so we always terminate DMA transaction on RX timeout interrupt. Timeout interval is set to 64 frame times. Based on previous work of Sylwester Nawrocki and Lukasz Czerwinski. Signed-off-by: Robert Baldyga <r.baldyga@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09serial: samsung: add DMA support for TXRobert Baldyga2-16/+225
Add TX DMA transfers support for samsung serial driver. It's enabled when "dmas" property is defined in serial device-tree node, otherwise TX transfers are prerformed using PIO. TX DMA is used for data segments larger than fifosize to reduce number of interrupts during data transmission. For buffers shorter than fifosize PIO mode is selected. Data blocks for DMA transfers are aligned to cache line size to avoid problems with coherency (some areas of TX circ buffer can be used by CPU during DMA transaction, so we have to ensure that our data is always consistent). Based on previous work of Sylwester Nawrocki and Lukasz Czerwinski. Signed-off-by: Robert Baldyga <r.baldyga@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09serial: samsung: add dma reqest/release functionsRobert Baldyga1-0/+101
Add functions requesting and releasing RX and TX DMA channels. This function are called only when "dmas" property in serial device-tree node is defined. Based on previous work of Sylwester Nawrocki and Lukasz Czerwinski. Signed-off-by: Robert Baldyga <r.baldyga@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09serial: samsung: alloc dma stucture in ourportRobert Baldyga1-0/+12
When we have "dmas" property in serial node in device-tree, we do memory alocation for dma structure which will be used in DMA handling code. Based on previous work of Sylwester Nawrocki and Lukasz Czerwinski. Signed-off-by: Robert Baldyga <r.baldyga@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09serial: samsung: add struct s3c24xx_uart_dmaRobert Baldyga1-0/+38
This struct contains DMA configuration for each serial port. It will be used in next commits adding DMA support in driver. Based on previous work of Sylwester Nawrocki and Lukasz Czerwinski. Signed-off-by: Robert Baldyga <r.baldyga@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09serial: imx: Support sw flow control in DMA modeJiada Wang1-2/+28
This patch adds Software flow control support in DMA mode. Signed-off-by: Jiada Wang <jiada_wang@mentor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09serial: imx: Fix issue in software flow controlJiada Wang1-0/+2
After send out x_char in UART driver, x_char needs to be cleared by UART driver itself, otherwise data in TXFIFO can no longer be sent out. Also tx counter needs to be increased to keep track of correct number of transmitted data. Signed-off-by: Jiada Wang <jiada_wang@mentor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09serial: imx: Enable UCR4_OREN in startup interfaceJiada Wang1-7/+8
Other than enable Receiver Overrun Interrupt Enable (UCR4_OREN) in start_tx interface, UCR4_OREN should be enabled before enable of Receiver. Signed-off-by: Jiada Wang <jiada_wang@mentor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09serial: imx: start rx_dma once RXFIFO is not emptyRobin Gong1-1/+14
Start rx_dma once RXFIFO is not empty that can avoid dma request lost and causes data delay issue. Signed-off-by: Robin Gong <b38343@freescale.com> Signed-off-by: Fugang Duan <B38611@freescale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09serial: imx: initialized DMA w/o HW flow enabledAnton Bondarenko1-7/+8
DMA mode for UART can be used even w/o HW flow control with RTS/CTS. So it need to be initialized and enabled earlier. Signed-off-by: Anton Bondarenko <anton_bondarenko@mentor.com> Signed-off-by: Jiada Wang <jiada_wang@mentor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09serial: imx: disable TDMAEN in imx_flush_buffer()Dirk Behme1-0/+15
Terminating the DMA, make sure the interrupt is disabled, too. This fixes random kernel Oops due to dma_tx_call() called for invalid transmissions. If we disable the TDMAEN, make sure it's enabled again if a TX DMA is started. Signed-off-by: Jiada Wang <jiada_wang@mentor.com> Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09serial: imx: call imx_dma_tx() again in dma_tx_callbackJiada Wang1-0/+6
Currently in dma_tx_callback(), no matter if there is still remaining data pending in circle buffer or not, DMA transmit will be terminated. This will result in some data never get transmitted. In order to fix this issue, call imx_dma_tx() again in dma_tx_callback, when there is pending data and uart hasn't been stopped. Signed-off-by: Jiada Wang <jiada_wang@mentor.com> Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09Revert "serial: imx: always wake up the processes in the TX callback"Jiada Wang1-1/+2
This reverts commit 2ad28e3efee21a5bbf940c83d1f0395b76bd3efb. Instead of always wake up write_wait process in TX callback, TX callback should call imx_dma_tx() again, and let imx_dma_tx transfer the remaining data in circle buffer. The issue with commit 2ad28e3 is, in case there is remaining data in circle buffer, but no process is waiting on write_wait queue, then as no following uart_write() will be called after uart_write_wakeup(), thus cause data loss. Moreover according to Documentation/serial/driver, uart_write_wakeup() should be called in case the transmit buffer have dropped below a threshold. Signed-off-by: Jiada Wang <jiada_wang@mentor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09serial: imx: use dma_is_txing to synchronize dma_tx_callback and imx_dma_txDirk Behme1-7/+7
To synchronize between dma_tx_callback() and imx_dma_tx() use the same variable, dma_is_txing. This prevents any race between these two functions and ensures that a new DMA can start only after the first has been finished. Before the new DMA can be set up, update the circular buffer logic, first. Therefore, change dma_is_txing after that update, instead of before. While doing this, in dma_tx_callback() extend the locking to dma_unmap_sg() and the update of dma_is_txing. Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09serial: imx: unmap scatter gather list in imx_flush_bufferDirk Behme1-3/+10
First, reformat the code to exit immediately. This allows us to add more code in more readable format. In case the TX DMA was still running, remove and disable it's resources. Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09serial: imx: unmap sg in case of dmaengine_prep_slave_sg() failureDirk Behme1-0/+3
In case dmaengine_prep_slave_sg() fails, add the missing dma_unmap_sg(). Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com> Signed-off-by: Anton Bondarenko <anton_bondarenko@mentor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09serial: imx: TX DMA: clean up sg initializationDirk Behme1-4/+4
Inverting the logic of the if statement for the sg initialization makes the if statement easier and better to read. No functional change. Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09serial: imx: remove unneeded imx_transmit_buffer() from imx_start_tx()Dirk Behme1-3/+0
Use imx_start_tx() just to enable the TX interrupt. It's the job of the TX interrupt ISR to fill the transmit buffer, then. If the transmit buffer is empty, the TX interrupt should be executed as soon as the start_tx() enables the interrupt, so there is no reason for the extra imx_transmit_buffer() call, here. Remove it. Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com> Signed-off-by: Andy Lowe <andy_lowe@mentor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09serial: imx: use locking to stop concurrent access of UCR1Jiada Wang1-0/+12
Several places are accessing the UCR1 register without locking. This probably will cause a race issue when another thread is accessing the same register. Add locking to preventing concurrent access of the UCR1 register. Signed-off-by: Jiada Wang <jiada_wang@mentor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09serial: imx: add CREAD flag supportJiada Wang1-1/+9
Add CREAD flag hanlding in set_termios and UART DMA mode which ignores all received chars when CREAD flag cleared. Signed-off-by: Jiada Wang <jiada_wang@mentor.com> Signed-off-by: Anton Bondarenko <anton_bondarenko@mentor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09tty/serial: at91: fix typo and indentationCyrille Pitchen1-18/+22
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09tty/serial: at91: fix RTS line management when hardware handshake is enabledCyrille Pitchen1-30/+61
This patch fixes many bugs in the code dealing with the hardware handshake. As an example, in atmel_set_termios(), we used to test whether the CRTSCTS c_cflag was set. If so, we selected the "Hardware Handshake" mode through the Mode Register. However, few lines below the mode was reset to "Normal" (0). So there was no way to select the "Hardware Handshake" mode. To fix this issue, we moved the CRTSCRTS c_cflag test AFTER the mode has been reset to "Normal". Also setting the RTSEN and RTSDIS bits in the Control Register has different results whether the USART is set in "Normal" or "Hardware Handshake" mode: 1) "Normal" mode - the RTSEN bit forces the RTS line to low level, which tells the remote peer that we are ready to received new data. - the RTSDIS bit forces the RTS line to high level, which tells the remote peer to stop sending new data. 2) "Hardware Handshake" mode - the RTSEN bit forces the RTS line to high level. - the RTSDIS bit lets the hardware control the RTS line. WARNING: when FIFOs are not available or not enabled, the RTS line is controlled by the PDC. This is why using the Hardware Handshake mode requires using the PDC channel for reception. However the Hardware Handshake mode DOES NOT work with DMA controller since it cannot control the RTS line. Future designs with FIFOs will introduce a new feature: the RTS line will be controlled by the RX FIFO using thresholds. This patch was tested with this new design. Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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