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path: root/drivers/tty/serial/serial-tegra.c
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2014-11-26serial: tegra: clean up tty-flag assignmentsJohan Hovold1-3/+3
The tty break and error flags are not bit masks so do not to use bitwise OR when assigning them. Note that there is no functional change due to the if-else construct and flag having been initialised to zero (TTY_NORMAL). Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-06serial: Refactor uart_flush_buffer() from uart_close()Peter Hurley1-14/+16
In the context of the final tty & port close, flushing the tx ring buffer after the hardware has already been shutdown and the ring buffer freed is neither required nor desirable. uart_flush_buffer() performs 3 operations: 1. Resets tx ring buffer indices, but the tx ring buffer has already been freed and the indices are reset if the port is re-opened. 2. Calls uart driver's flush_buffer() method 5 in-tree uart drivers define flush_buffer() methods: amba-pl011, atmel-serial, imx, serial-tegra, timbuart These have been refactored into the shutdown() method, if required. 3. Kicks the ldisc for more writing, but this is undesirable. The file handle is being released; any waiting writer will will be kicked out by tty_release() with a warning. Further, the N_TTY ldisc may generate SIGIO for a file handle which is no longer valid. Cc: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-11serial: tegra: ack the rx dma desc after transfer terminatedPradeep Goudagunta1-0/+1
The Rx dma descriptor allocated without the DMA_ACK flags so that once after tarnsfer done or terminated, client can ack the descriptor to free it for later use. If the Rx DMA is terminated for some reason then rx-dma descriptor is not getting acked which causes the memory leak and list of usage desc to grow continuously. Hence, acknowledge the rx-dma descriptor once transfer is terminated to avoid memory leak and desc list to grow. Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-11serial: tegra: update tx_circular buffer only when TX_DMA is in progressPradeep Goudagunta1-0/+3
When channel is require to stop transmit then update the Tx circular buffer only when DMA based transfer is in progress. If there is no DMA based transfer then no need to update the Tx buffer. Signed-off-by: Pradeep Goudagunta <pgoudagunta@nvidia.com> Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-12serial: tegra: convert to standard DMA DT bindingsStephen Warren1-18/+6
By using dma_request_slave_channel_or_err(), the DMA slave ID can be looked up from standard DT properties, and squirrelled away during channel allocation. Hence, there's no need to use a custom DT property to store the slave ID. Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Stephen Warren <swarren@nvidia.com> Reviewed-by: Thierry Reding <treding@nvidia.com>
2013-12-12serial: tegra: use reset frameworkStephen Warren1-4/+10
Tegra's clock driver now provides an implementation of the common reset API (include/linux/reset.h). Use this instead of the old Tegra- specific API; that will soon be removed. Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Thierry Reding <treding@nvidia.com>
2013-10-07serial: tegra: remove deprecated IRQF_DISABLEDMichael Opdenacker1-1/+1
This patch proposes to remove the use of the IRQF_DISABLED flag It's a NOOP since 2.6.35 and it will be removed one day. Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-17serial: tegra: fix tty-kref leakJohan Hovold1-1/+3
Fix potential tty-kref leak in stop_rx path. Cc: stable@vger.kernel.org Signed-off-by: Johan Hovold <jhovold@gmail.com> Tested-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-28tty: serial: tegra: drop uart_port->lock before calling tty_flip_buffer_push()Viresh Kumar1-2/+8
The current driver triggers a lockdep warning for if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels and comes up only on SMP kernels. Crash looks like this (produced with samsung.c driver): ----- [<c0014d58>] (unwind_backtrace+0x0/0xf8) from [<c0011908>] (show_stack+0x10/0x14) [<c0011908>] (show_stack+0x10/0x14) from [<c035da34>] (dump_stack+0x6c/0xac) [<c035da34>] (dump_stack+0x6c/0xac) from [<c01b59ac>] (do_raw_spin_unlock+0xc4/0xd8) [<c01b59ac>] (do_raw_spin_unlock+0xc4/0xd8) from [<c03627e4>] (_raw_spin_unlock_irqrestore+0xc/0) [<c03627e4>] (_raw_spin_unlock_irqrestore+0xc/0x38) from [<c020a1a8>] (s3c24xx_serial_rx_chars+0) [<c020a1a8>] (s3c24xx_serial_rx_chars+0x12c/0x260) from [<c020aae8>] (s3c64xx_serial_handle_irq+) [<c020aae8>] (s3c64xx_serial_handle_irq+0x48/0x60) from [<c006aaa0>] (handle_irq_event_percpu+0x) [<c006aaa0>] (handle_irq_event_percpu+0x50/0x194) from [<c006ac20>] (handle_irq_event+0x3c/0x5c) [<c006ac20>] (handle_irq_event+0x3c/0x5c) from [<c006d864>] (handle_fasteoi_irq+0x80/0x13c) [<c006d864>] (handle_fasteoi_irq+0x80/0x13c) from [<c006a4a4>] (generic_handle_irq+0x20/0x30) [<c006a4a4>] (generic_handle_irq+0x20/0x30) from [<c000f454>] (handle_IRQ+0x38/0x94) [<c000f454>] (handle_IRQ+0x38/0x94) from [<c0008538>] (gic_handle_irq+0x34/0x68) [<c0008538>] (gic_handle_irq+0x34/0x68) from [<c00123c0>] (__irq_svc+0x40/0x70) Exception stack(0xc04cdf70 to 0xc04cdfb8) df60: 00000000 00000000 0000166e 00000000 df80: c04cc000 c050278f c050278f 00000001 c04d444c 410fc0f4 c03649b0 00000000 dfa0: 00000001 c04cdfb8 c000f758 c000f75c 60070013 ffffffff [<c00123c0>] (__irq_svc+0x40/0x70) from [<c000f75c>] (arch_cpu_idle+0x28/0x30) [<c000f75c>] (arch_cpu_idle+0x28/0x30) from [<c0054888>] (cpu_startup_entry+0x5c/0x148) [<c0054888>] (cpu_startup_entry+0x5c/0x148) from [<c0497aa4>] (start_kernel+0x334/0x38c) BUG: spinlock lockup suspected on CPU#0, kworker/0:1/360 lock: s3c24xx_serial_ports+0x1d8/0x370, .magic: dead4ead, .owner: <none>/-1, .owner_cpu: -1 CPU: 0 PID: 360 Comm: kworker/0:1 Not tainted 3.11.0-rc6-next-20130819-00003-g75485f1 #2 Workqueue: events flush_to_ldisc [<c0014d58>] (unwind_backtrace+0x0/0xf8) from [<c0011908>] (show_stack+0x10/0x14) [<c0011908>] (show_stack+0x10/0x14) from [<c035da34>] (dump_stack+0x6c/0xac) [<c035da34>] (dump_stack+0x6c/0xac) from [<c01b581c>] (do_raw_spin_lock+0x100/0x17c) [<c01b581c>] (do_raw_spin_lock+0x100/0x17c) from [<c03628a0>] (_raw_spin_lock_irqsave+0x20/0x28) [<c03628a0>] (_raw_spin_lock_irqsave+0x20/0x28) from [<c0203224>] (uart_start+0x18/0x34) [<c0203224>] (uart_start+0x18/0x34) from [<c01ef890>] (__receive_buf+0x4b4/0x738) [<c01ef890>] (__receive_buf+0x4b4/0x738) from [<c01efb44>] (n_tty_receive_buf2+0x30/0x98) [<c01efb44>] (n_tty_receive_buf2+0x30/0x98) from [<c01f2ba8>] (flush_to_ldisc+0xec/0x138) [<c01f2ba8>] (flush_to_ldisc+0xec/0x138) from [<c0031af0>] (process_one_work+0xfc/0x348) [<c0031af0>] (process_one_work+0xfc/0x348) from [<c0032138>] (worker_thread+0x138/0x37c) [<c0032138>] (worker_thread+0x138/0x37c) from [<c0037a7c>] (kthread+0xa4/0xb0) [<c0037a7c>] (kthread+0xa4/0xb0) from [<c000e5f8>] (ret_from_fork+0x14/0x3c) ----- Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call. Similar stuff was already done for few other drivers in the past, like: commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner <tglx@linutronix.de> Date: Tue May 29 21:53:50 2007 +0100 [ARM] 4417/1: Serial: Fix AMBA drivers locking Cc: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-12serial: tegra: use NULL instead of 0Jingoo Han1-3/+3
'cons' is a pointer; thus NULL should be used instead of 0. Also, local symbols are staticized. Fix the following sparse warnings: drivers/tty/serial/serial-tegra.c:1209:27: warning: Using plain integer as NULL pointer drivers/tty/serial/serial-tegra.c:1240:29: warning: symbol 'tegra20_uart_chip_data' was not declared. Should it be static? drivers/tty/serial/serial-tegra.c:1246:29: warning: symbol 'tegra30_uart_chip_data' was not declared. Should it be static? Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-28treewide: Fix typo in printkMasanari Iida1-1/+1
Correct spelling typo in various part of drivers Signed-off-by: Masanari Iida <standby24x7@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-03-16serial: tegra: Convert to devm_ioremap_resource()Sachin Kamat1-5/+4
Use the newly introduced devm_ioremap_resource() instead of devm_request_and_ioremap() which provides more consistent error handling. devm_ioremap_resource() provides its own error messages; so all explicit error messages can be removed from the failure code paths. Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org> Reviewed-by: Thierry Reding <thierry.reding@avionic-design.de> Cc: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-16serial: tegra: assume CONFIG_OFStephen Warren1-3/+2
Tegra only supports, and always enables, device tree. Remove all ifdefs for DT support from the driver. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-25serial: tegra: Fix compilation errorVenu Byravarasu1-1/+1
Fix compilation error, by adding the correct header file for Tegra clocks. Signed-off-by: Venu Byravarasu <vbyravarasu@nvidia.com> Reviewed-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-18serial: tegra: Switch to using struct tty_portThierry Reding1-12/+15
Many of the tty functions were converted to use a struct tty_port instead of a struct tty_struct. Update the Tegra driver accordingly to avoid build breakage. Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-16serial: tegra: add serial driverLaxman Dewangan1-0/+1399
NVIDIA's Tegra has multiple UART controller which supports: - APB DMA based controller fifo read/write. - End Of Data interrupt in incoming data to know whether end of frame achieve or not. - HW controlled RTS and CTS flow control to reduce SW overhead. Add serial driver to use all above feature. Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com> Acked-by: Alan Cox <alan@linux.intel.com> Reviewed-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>