[PATCH 02/25] serial: bfin_sport_uart: shorten the SPORT TX waiting loop
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From: Greg Kroah-Hartman on 21 May 2010 13:10 From: Sonic Zhang <sonic.zhang(a)analog.com> The waiting loop to stop SPORT TX from TX interrupt is too long. This may block the SPORT RX interrupts and cause the RX FIFO to overflow. So, do stop sport TX only after the last char in TX FIFO is moved into the shift register. Signed-off-by: Sonic Zhang <sonic.zhang(a)analog.com> Signed-off-by: Mike Frysinger <vapier(a)gentoo.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)suse.de> --- drivers/serial/bfin_sport_uart.c | 8 +++++++- 1 files changed, 7 insertions(+), 1 deletions(-) diff --git a/drivers/serial/bfin_sport_uart.c b/drivers/serial/bfin_sport_uart.c index c88f8ad..6991c36 100644 --- a/drivers/serial/bfin_sport_uart.c +++ b/drivers/serial/bfin_sport_uart.c @@ -271,7 +271,13 @@ static void sport_uart_tx_chars(struct sport_uart_port *up) } if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) { - sport_stop_tx(&up->port); + /* The waiting loop to stop SPORT TX from TX interrupt is + * too long. This may block SPORT RX interrupts and cause + * RX FIFO overflow. So, do stop sport TX only after the last + * char in TX FIFO is moved into the shift register. + */ + if (SPORT_GET_STAT(up) & TXHRE) + sport_stop_tx(&up->port); return; } -- 1.7.0.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |