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mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-22 20:23:57 +08:00
linux-next/drivers
Paul Walmsley 0ba5f66836 tty: serial: OMAP: use a 1-byte RX FIFO threshold in PIO mode
In the (default) PIO mode, use a one-byte RX FIFO threshold.  The OMAP
UART IP blocks do not appear to be capable of waking the system under
an RX timeout condition.  Since the previous RX FIFO threshold was 16
bytes, this meant that omap-serial.c did not become aware of any
received data until all those bytes arrived or until another UART
interrupt occurred.  This made the serial console and presumably other
serial applications (GPS, serial Bluetooth) unusable or extremely
slow.  A 1-byte RX FIFO threshold also allows the MPU to enter a
low-power consumption state while waiting for the FIFO to fill.

This can be verified using the serial console by comparing the
behavior when "0123456789abcde" is pasted in from another window, with
the behavior when "0123456789abcdef" is pasted in.  Since the former
string is less than sixteen bytes long, the string is not echoed for
some time, while the latter string is echoed immediately.

DMA operation is unaffected by this patch.

Thanks to Russell King - ARM Linux <linux@arm.linux.org.uk> for some
additional information on the standard behavior of the RX timeout
event, which was used to improve this commit description.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Govindraj Raja <govindraj.r@ti.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Russell King <linux@arm.linux.org.uk>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-02-09 10:48:32 -08:00
..
accessibility module_param: make bool parameters really bool (drivers & misc) 2012-01-13 09:32:20 +10:30
acpi Merge branches 'atomicio-apei', 'hotplug', 'sony-nvs-nosave' and 'thermal-netlink' into release 2012-01-23 19:47:06 -05:00
amba Merge branch 'pm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm 2012-01-08 13:10:57 -08:00
ata [libata] ata_piix: Add Toshiba Satellite Pro A120 to the quirks list 2012-01-17 20:50:53 -05:00
atm module_param: make bool parameters really bool (drivers & misc) 2012-01-13 09:32:20 +10:30
auxdisplay
base Here are some patches for the 3.3-rc1 tree. 2012-01-28 18:20:48 -08:00
bcma bcma: connect the bcma bus suspend/resume to the bcma driver suspend/resume 2012-01-17 09:54:08 -05:00
block nvme: fix merge error due to change of 'make_request_fn' fn type 2012-01-18 15:41:27 -08:00
bluetooth module_param: make bool parameters really bool (drivers & misc) 2012-01-13 09:32:20 +10:30
cdrom block: add and use scsi_blk_cmd_ioctl 2012-01-14 15:07:24 -08:00
char agp: fix scratch page cleanup 2012-01-26 18:36:48 +00:00
clk clk: add config option HAVE_CLK_PREPARE into Kconfig 2011-12-28 21:35:06 +08:00
clocksource Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm 2012-01-06 18:15:25 -08:00
connector
cpufreq Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq 2012-01-11 18:53:33 -08:00
cpuidle
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2012-01-10 22:01:27 -08:00
dca
devfreq
dio
dma Merge branch 'next' of git://git.infradead.org/users/vkoul/slave-dma 2012-01-17 18:40:24 -08:00
edac module_param: make bool parameters really bool (drivers & misc) 2012-01-13 09:32:20 +10:30
eisa
firewire module_param: make bool parameters really bool (drivers & misc) 2012-01-13 09:32:20 +10:30
firmware Merge commit '070680218379e15c1901f4bf21b98e3cbf12b527' into stable/for-linus-fixes-3.3 2012-01-12 11:53:55 -05:00
gpio gpio: tps65910: Use correct offset for gpio initialization 2012-01-18 13:48:43 -07:00
gpu vmwgfx: Fix assignment in vmw_framebuffer_create_handle 2012-01-30 09:32:39 +00:00
hid module_param: make bool parameters really bool (drivers & misc) 2012-01-13 09:32:20 +10:30
hv Merge branch 'usb-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb 2012-01-09 12:09:47 -08:00
hwmon hwmon: (w83627ehf) Disable setting DC mode for pwm2, pwm3 on NCT6776F 2012-01-29 13:06:07 -08:00
hwspinlock
i2c Merge branches 'for-33/i2c/eg20t' and 'for-33/i2c/omap' into for-linus/i2c-33 2012-01-17 23:30:41 +00:00
ide block: add and use scsi_blk_cmd_ioctl 2012-01-14 15:07:24 -08:00
idle ACPI processor hotplug: Delay acpi_processor_start() call for hotplugged cores 2012-01-19 21:26:32 -05:00
ieee802154
infiniband Merge branch 'for-next-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2012-01-18 16:29:42 -08:00
input Autogenerated GPG tag for Rusty D1ADB8F1: 15EE 8D6C AB0E 7F0C F999 BFCB D920 0E6C D1AD B8F1 2012-01-14 12:32:16 -08:00
iommu Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu 2012-01-10 11:08:21 -08:00
isdn Autogenerated GPG tag for Rusty D1ADB8F1: 15EE 8D6C AB0E 7F0C F999 BFCB D920 0E6C D1AD B8F1 2012-01-14 12:32:16 -08:00
leds leds: add led driver for Bachmann's ot200 2012-01-23 08:38:47 -08:00
lguest lguest: Make sure interrupt is allocated ok by lguest_setup_irq 2012-01-12 15:44:47 +10:30
macintosh module_param: make bool parameters really bool (drivers & misc) 2012-01-13 09:32:20 +10:30
mca
md Merge branch 'for-3.3/core' of git://git.kernel.dk/linux-block 2012-01-15 12:24:45 -08:00
media Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2012-01-26 17:04:47 -08:00
memstick module_param: make bool parameters really bool (drivers & misc) 2012-01-13 09:32:20 +10:30
message SCSI updates for post 3.2 merge window 2012-01-10 10:36:08 -08:00
mfd MFD: ucb1x00-ts: fix resume failure 2012-01-22 21:10:40 +00:00
misc Merge branch 'next' of git://git.infradead.org/users/vkoul/slave-dma 2012-01-17 18:40:24 -08:00
mmc Merge branch 'next' of git://git.infradead.org/users/vkoul/slave-dma 2012-01-17 18:40:24 -08:00
mtd Merge branch 'next' of git://git.infradead.org/users/vkoul/slave-dma 2012-01-17 18:40:24 -08:00
net Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless 2012-01-27 20:40:18 -05:00
nfc Merge branch 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core 2012-01-07 12:03:30 -08:00
nubus
of 2nd set of device tree changes for v3.3 2012-01-14 13:25:55 -08:00
oprofile Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-01-06 08:02:58 -08:00
parisc Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci 2012-01-11 18:50:26 -08:00
parport Autogenerated GPG tag for Rusty D1ADB8F1: 15EE 8D6C AB0E 7F0C F999 BFCB D920 0E6C D1AD B8F1 2012-01-14 12:32:16 -08:00
pci kernel-doc: fix new warnings in pci 2012-01-23 08:44:53 -08:00
pcmcia PCMCIA: fix sa1111 oops on remove 2012-01-24 21:33:26 +00:00
pinctrl pinctrl: add checks for empty function names 2012-01-26 14:13:11 +01:00
platform module_param: make bool parameters really bool (drivers & misc) 2012-01-13 09:32:20 +10:30
pnp PNP: work around Dell 1536/1546 BIOS MMCONFIG bug that breaks USB 2012-01-06 12:11:20 -08:00
power module_param: make bool parameters really bool (drivers & misc) 2012-01-13 09:32:20 +10:30
pps
ps3
ptp
rapidio
regulator This fixes an integration issue with the regulator device tree bindings 2012-01-30 10:16:25 -08:00
rtc Revert "RTC: sa1100: remove redundant code of setting alarm" 2012-01-19 17:26:26 +00:00
s390 [S390] dasd: revalidate server for new pathgroup 2012-01-18 18:03:42 +01:00
sbus
scsi Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k 2012-01-26 12:43:57 -08:00
sfi
sh SH/R-Mobile updates for 3.3 merge window. 2012-01-11 23:29:20 -08:00
sn
spi Merge branch 'next' of git://git.infradead.org/users/vkoul/slave-dma 2012-01-17 18:40:24 -08:00
ssb
staging Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2012-01-15 12:49:56 -08:00
target
tc
telephony
thermal thermal: Rename generate_netlink_event 2012-01-23 03:15:25 -05:00
tty tty: serial: OMAP: use a 1-byte RX FIFO threshold in PIO mode 2012-02-09 10:48:32 -08:00
uio Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci 2012-01-11 18:50:26 -08:00
usb Here are a bunch of USB patches for 3.3-rc1. 2012-01-30 11:38:28 -08:00
uwb Merge branch 'usb-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb 2012-01-09 12:09:47 -08:00
vhost vhost-net: add module alias (v2.1) 2012-01-13 10:12:23 -08:00
video Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k 2012-01-26 12:43:57 -08:00
virt
virtio virtio: correct the memory barrier in virtqueue_kick_prepare() 2012-01-28 08:10:23 +10:30
vlynq
w1
watchdog watchdog: iTCO_wdt: add Intel Lynx Point DeviceIDs 2012-01-27 10:01:16 +01:00
xen xen/granttable: Disable grant v2 for HVM domains. 2012-01-27 11:14:16 -05:00
zorro misc latin1 to utf8 conversions 2012-01-02 13:04:55 +01:00
Kconfig
Makefile mmc: sdhci-pci: add platform data 2012-01-11 23:58:47 -05:00