kernel/drivers/tty/serial/serial-tegra.c, branch linux-4.1.y

tty: constify of_device_id array

2015-03-26T21:49:10Z

of_device_id is always used as const. (See driver.of_match_table and open firmware functions) Signed-off-by: Fabian Frederick Acked-by: Peter Korsgaard Acked-by: Timur Tabi Acked-by: Patrice Chotard Signed-off-by: Greg Kroah-Hartman

serial: tegra: clean up tty-flag assignments

2014-11-26T01:06:39Z

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 Signed-off-by: Greg Kroah-Hartman

serial: Refactor uart_flush_buffer() from uart_close()

2014-11-06T02:53:54Z

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 Further, the N_TTY ldisc may generate SIGIO for a file handle which is no longer valid.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 Cc: Russell King Cc: Laxman Dewangan Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

serial: tegra: ack the rx dma desc after transfer terminated

2014-07-10T22:53:20Z

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 Signed-off-by: Greg Kroah-Hartman

serial: tegra: update tx_circular buffer only when TX_DMA is in progress

2014-07-10T22:53:20Z

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 Signed-off-by: Laxman Dewangan Signed-off-by: Greg Kroah-Hartman

serial: tegra: convert to standard DMA DT bindings

2013-12-11T23:44:35Z

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 Signed-off-by: Stephen Warren Reviewed-by: Thierry Reding

serial: tegra: use reset framework

2013-12-11T23:44:28Z

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 Acked-by: Greg Kroah-Hartman Reviewed-by: Thierry Reding

serial: tegra: remove deprecated IRQF_DISABLED

2013-10-07T07:13:58Z

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 Signed-off-by: Greg Kroah-Hartman

serial: tegra: fix tty-kref leak

2013-09-17T17:05:47Z

Fix potential tty-kref leak in stop_rx path. Cc: stable@vger.kernel.org Signed-off-by: Johan Hovold Tested-by: Stephen Warren Signed-off-by: Greg Kroah-Hartman

tty: serial: tegra: drop uart_port->lock before calling tty_flip_buffer_push()

2013-08-27T23:17:35Z

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): ----- [] (unwind_backtrace+0x0/0xf8) from [] (show_stack+0x10/0x14) [] (show_stack+0x10/0x14) from [] (dump_stack+0x6c/0xac) [] (dump_stack+0x6c/0xac) from [] (do_raw_spin_unlock+0xc4/0xd8) [] (do_raw_spin_unlock+0xc4/0xd8) from [] (_raw_spin_unlock_irqrestore+0xc/0) [] (_raw_spin_unlock_irqrestore+0xc/0x38) from [] (s3c24xx_serial_rx_chars+0) [] (s3c24xx_serial_rx_chars+0x12c/0x260) from [] (s3c64xx_serial_handle_irq+) [] (s3c64xx_serial_handle_irq+0x48/0x60) from [] (handle_irq_event_percpu+0x) [] (handle_irq_event_percpu+0x50/0x194) from [] (handle_irq_event+0x3c/0x5c) [] (handle_irq_event+0x3c/0x5c) from [] (handle_fasteoi_irq+0x80/0x13c) [] (handle_fasteoi_irq+0x80/0x13c) from [] (generic_handle_irq+0x20/0x30) [] (generic_handle_irq+0x20/0x30) from [] (handle_IRQ+0x38/0x94) [] (handle_IRQ+0x38/0x94) from [] (gic_handle_irq+0x34/0x68) [] (gic_handle_irq+0x34/0x68) from [] (__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 [] (__irq_svc+0x40/0x70) from [] (arch_cpu_idle+0x28/0x30) [] (arch_cpu_idle+0x28/0x30) from [] (cpu_startup_entry+0x5c/0x148) [] (cpu_startup_entry+0x5c/0x148) from [] (start_kernel+0x334/0x38c) BUG: spinlock lockup suspected on CPU#0, kworker/0:1/360 lock: s3c24xx_serial_ports+0x1d8/0x370, .magic: dead4ead, .owner: /-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 [] (unwind_backtrace+0x0/0xf8) from [] (show_stack+0x10/0x14) [] (show_stack+0x10/0x14) from [] (dump_stack+0x6c/0xac) [] (dump_stack+0x6c/0xac) from [] (do_raw_spin_lock+0x100/0x17c) [] (do_raw_spin_lock+0x100/0x17c) from [] (_raw_spin_lock_irqsave+0x20/0x28) [] (_raw_spin_lock_irqsave+0x20/0x28) from [] (uart_start+0x18/0x34) [] (uart_start+0x18/0x34) from [] (__receive_buf+0x4b4/0x738) [] (__receive_buf+0x4b4/0x738) from [] (n_tty_receive_buf2+0x30/0x98) [] (n_tty_receive_buf2+0x30/0x98) from [] (flush_to_ldisc+0xec/0x138) [] (flush_to_ldisc+0xec/0x138) from [] (process_one_work+0xfc/0x348) [] (process_one_work+0xfc/0x348) from [] (worker_thread+0x138/0x37c) [] (worker_thread+0x138/0x37c) from [] (kthread+0xa4/0xb0) [] (kthread+0xa4/0xb0) from [] (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 Date: Tue May 29 21:53:50 2007 +0100 [ARM] 4417/1: Serial: Fix AMBA drivers locking Cc: Stephen Warren Signed-off-by: Viresh Kumar Signed-off-by: Greg Kroah-Hartman