serial: bfin_sport_uart: work around anomaly 05000473 (make 32bit fifo read atomic)

We cannot let a 32-bit RX FIFO read be interrupted otherwise a fake RX
underflow error might be generated.

URL: http://blackfin.uclinux.org/gf/tracker/5145

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Sonic Zhang 2010-03-09 12:25:28 -05:00 committed by Greg Kroah-Hartman
parent d7dbf4ffee
commit a5a420d207
1 changed files with 15 additions and 1 deletions

View File

@ -37,7 +37,21 @@
#define SPORT_GET_TFSDIV(sport) bfin_read16(((sport)->port.membase + OFFSET_TFSDIV))
#define SPORT_GET_TX(sport) bfin_read16(((sport)->port.membase + OFFSET_TX))
#define SPORT_GET_RX(sport) bfin_read16(((sport)->port.membase + OFFSET_RX))
#define SPORT_GET_RX32(sport) bfin_read32(((sport)->port.membase + OFFSET_RX))
/*
* If another interrupt fires while doing a 32-bit read from RX FIFO,
* a fake RX underflow error will be generated. So disable interrupts
* to prevent interruption while reading the FIFO.
*/
#define SPORT_GET_RX32(sport) \
({ \
unsigned int __ret; \
if (ANOMALY_05000473) \
local_irq_disable(); \
__ret = bfin_read32((sport)->port.membase + OFFSET_RX); \
if (ANOMALY_05000473) \
local_irq_enable(); \
__ret; \
})
#define SPORT_GET_RCR1(sport) bfin_read16(((sport)->port.membase + OFFSET_RCR1))
#define SPORT_GET_RCR2(sport) bfin_read16(((sport)->port.membase + OFFSET_RCR2))
#define SPORT_GET_RCLKDIV(sport) bfin_read16(((sport)->port.membase + OFFSET_RCLKDIV))