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authorSonic Zhang <sonic.zhang@analog.com>2010-03-09 12:25:29 -0500
committerGreg Kroah-Hartman <gregkh@suse.de>2010-05-21 09:34:27 -0700
commit3f3a978b9f4a513610b32f16670914006a61067f (patch)
treebd7f6b46a8f7c153ba370e0382a9dc7dc7ab1cea /drivers/serial
parenta5a420d207df40226afbf828c12bd9b4c6e058ef (diff)
serial: bfin_sport_uart: shorten the SPORT TX waiting loop
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@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.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/serial/bfin_sport_uart.c b/drivers/serial/bfin_sport_uart.c
index c88f8ad3ff82..6991c3605f9c 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;
}