linux/drivers/tty
Peter Senna Tschudin 18a4208826 imx-serial: Reduce RX DMA startup latency when opening for reading
Reduce RX DMA start latency for the first reception when port is opened
for reading. Instead of waiting for an interrupt signaling data on RX
FIFO or data too old on RX FIFO, start RX DMA immediately when the
serial port is opened for reading.

Before this patch, the average RX DMA latency for the first reception
was 42489 microseconds with a standard deviation of 25721 microseconds
in 36 samples.

After the patch the average RX DMA latency for the first reception, when
the serial port is opened for reading, is 653 microseconds with a
standard deviation of 294 microseconds in 36 samples.

Signed-off-by: Peter Senna Tschudin <peter.senna@collabora.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-11 21:36:43 +02:00
..
hvc tty/hvc_console: fix console lock ordering with spinlock 2017-03-31 11:37:13 +02:00
ipwireless tty: ipwireless, cleanup TIOCGSERIAL 2016-06-25 08:56:30 -07:00
serdev serdev: Add serdev_device_write subroutine 2017-04-08 18:51:00 +02:00
serial imx-serial: Reduce RX DMA startup latency when opening for reading 2017-04-11 21:36:43 +02:00
vt Merge 4.11-rc5 into tty-next 2017-04-03 14:18:16 +02:00
amiserial.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
bfin_jtag_comm.c
cyclades.c tty: stop defining STD_COM_FLAGS in drivers 2016-06-25 08:56:30 -07:00
ehv_bytechan.c drivers/tty: make ehv_bytechan.c explicitly non-modular 2016-02-06 23:26:43 -08:00
goldfish.c tty: goldfish: Fix a parameter of a call to free_irq 2017-01-12 11:51:25 +01:00
isicom.c tty: Replace ASYNC_INITIALIZED bit and update atomically 2016-04-30 09:26:55 -07:00
Kconfig devpts: Make each mount of devpts an independent filesystem. 2016-06-05 10:36:01 -07:00
Makefile serdev: Introduce new bus for serial attached devices 2017-02-03 10:17:02 +01:00
metag_da.c timers, drivers/tty/metag_da: Initialize the poll timer as pinned 2016-07-07 10:25:14 +02:00
mips_ejtag_fdc.c timers, drivers/tty/mips_ejtag: Initialize the poll timer as pinned 2016-07-07 10:34:59 +02:00
moxa.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
moxa.h
mxser.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mxser.h
n_gsm.c tty: n_gsm: Use net_device_stats from struct net_device 2017-03-17 14:14:00 +09:00
n_hdlc.c tty: n_hdlc: get rid of racy n_hdlc.tbuf 2017-03-07 18:54:30 +01:00
n_r3964.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
n_tracerouter.c n_tracerouter: stop including <asm-generic/bug> 2015-10-15 00:21:10 +02:00
n_tracesink.c n_tracesink: stop including <asm-generic/bug> 2015-10-15 00:21:11 +02:00
n_tracesink.h
n_tty.c Fix OpenSSH pty regression on close 2016-05-01 13:22:54 -07:00
nozomi.c tty: nozomi: avoid sprintf buffer overflow 2016-11-29 20:20:07 +01:00
pty.c tty: pty: Fix ldisc flush after userspace become aware of the data already 2017-03-17 14:16:09 +09:00
rocket_int.h tty: rocket: Remove private close_wait 2016-01-28 14:13:44 -08:00
rocket.c tty: rocket: fix invalid user-pointer checks 2016-11-10 14:41:25 +01:00
rocket.h
synclink_gt.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
synclink.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
synclinkmp.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
sysrq.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h> 2017-03-02 08:42:35 +01:00
tty_audit.c tty: audit: remove unused variable 2016-03-07 16:11:14 -08:00
tty_buffer.c tty_port: Add port client functions 2017-02-03 10:17:02 +01:00
tty_io.c tty: fix comment typo s/repsonsible/responsible/ 2017-04-08 18:54:07 +02:00
tty_ioctl.c sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
tty_ldisc.c Revert "tty: Fix ldisc crash on reopened tty" 2017-03-29 07:50:49 +02:00
tty_ldsem.c sched/headers: Prepare to move the get_task_struct()/put_task_struct() and related APIs from <linux/sched.h> to <linux/sched/task.h> 2017-03-02 08:42:40 +01:00
tty_mutex.c Merge 4.5-rc4 into tty-next 2016-02-14 14:36:04 -08:00
tty_port.c sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00