audk/ArmPlatformPkg/Drivers
Evan Lloyd 16146b984d ArmPlatformPkg: Fix PL011 Glitches.
This change corrects 3 problems in the PL011 driver.
1. The TRM states "The UARTLCR_H, UARTIBRD, and UARTFBRD registers must
   not be changed:...when the UART is enabled"
2. The TRM (3.3.8) describes logic requiring the UART to be disabled and
   flushed before adjusting UARTCR.
3. Several redundant calls get made to PL011UartInitializePort, where
   the characteristics do not change, but updating the registers can
   cause glitches in the output stream.

The parameters are compared to the current state and no action taken if
no change of state is required.
Where an update is required, the specified logic is followed, and the
register updates only made when the UART is disabled.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Signed-off-by: Evan Lloyd <evan.lloyd@arm.com>
Tested-by: Ryan Harkin <ryan.harkin@linaro.org>
Reviewed-by: Ryan Harkin <ryan.harkin@linaro.org>
2016-06-15 16:17:10 +02:00
..
ArmTrustZone ARM Packages: Removed trailing spaces 2014-08-19 13:29:52 +00:00
LcdGraphicsOutputDxe ArmPlatformPkg/HdLcd: add missing LcdIdentify() 2015-09-04 10:02:43 +00:00
NorFlashDxe ArmPlatformPkg: NorFlashDxe: mellow DEBUG messages about flash reinit 2015-10-16 15:46:28 +00:00
PL011Uart ArmPlatformPkg: Fix PL011 Glitches. 2016-06-15 16:17:10 +02:00
PL34xDmc ArmPlatformPkg: Rectify file modes 2016-02-02 11:42:31 +00:00
PL35xSmc ArmPlatformPkg: Rectify file modes 2016-02-02 11:42:31 +00:00
PL061GpioDxe ArmPlatformPkg: PL061: support multiple controller 2016-03-14 13:17:34 +00:00
PL180MciDxe ArmPlatformPkg/PL180MciDxe: don't check ID_REG3 2016-03-01 18:06:24 +00:00
PL301Axi ArmPlatformPkg: Rectify file modes 2016-02-02 11:42:31 +00:00
PL310L2Cache ArmPlatformPkg: Rectify file modes 2016-02-02 11:42:31 +00:00
SP804TimerDxe ARM Packages: Removed trailing spaces 2014-08-19 13:29:52 +00:00
SP805WatchdogDxe ARM Packages: Removed trailing spaces 2014-08-19 13:29:52 +00:00