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| author |   Sonic Zhang <sonic.zhang@analog.com> | 2010-03-09 12:25:28 -0500 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@suse.de> | 2010-05-21 09:34:27 -0700 |
| commit | a5a420d207df40226afbf828c12bd9b4c6e058ef (patch) | |
| tree | af4d91ce3f0f65728bbf6a7da86a5ee5e867292f /drivers/serial | |
| parent | Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2 (diff) | |
| download | linux-dev-a5a420d207df40226afbf828c12bd9b4c6e058ef.tar.xz linux-dev-a5a420d207df40226afbf828c12bd9b4c6e058ef.zip | |
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>
Diffstat (limited to 'drivers/serial')
| -rw-r--r-- | drivers/serial/bfin_sport_uart.h | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/drivers/serial/bfin_sport_uart.h b/drivers/serial/bfin_sport_uart.h index abe03614e4df..9791fcc80a74 100644 --- a/drivers/serial/bfin_sport_uart.h +++ b/drivers/serial/bfin_sport_uart.h @@ -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)) |