From a5a420d207df40226afbf828c12bd9b4c6e058ef Mon Sep 17 00:00:00 2001 From: Sonic Zhang Date: Tue, 9 Mar 2010 12:25:28 -0500 Subject: [PATCH] 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 Signed-off-by: Mike Frysinger Signed-off-by: Greg Kroah-Hartman --- drivers/serial/bfin_sport_uart.h | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/drivers/serial/bfin_sport_uart.h b/drivers/serial/bfin_sport_uart.h index abe03614e4d..9791fcc80a7 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)) -- 2.20.1