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authorSonic Zhang <sonic.zhang@analog.com>2012-03-13 15:51:55 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-03-13 14:33:39 -0700
commit60f4b002ab209525c2b818703291ac9a14890e17 (patch)
tree60c771ae0b9cc03e7687f3486f38c3d5d0a6027a /drivers/tty/serial
parent82896210aa3c59eaa4f78f7ba2f5f947601dd8f8 (diff)
serial: bfin-uart: Don't access tty circular buffer in TX DMA interrupt after it is reset.
When kernel reboot, tty circular buffer is reset before last TX DMA interrupt is called, while the buffer tail is updated in TX DMA interrupt handler. So, don't update the buffer tail if it is reset. Signed-off-by: Sonic Zhang <sonic.zhang@analog.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial')
-rw-r--r--drivers/tty/serial/bfin_uart.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/tty/serial/bfin_uart.c b/drivers/tty/serial/bfin_uart.c
index 26953bfa692..5832fdef11e 100644
--- a/drivers/tty/serial/bfin_uart.c
+++ b/drivers/tty/serial/bfin_uart.c
@@ -535,11 +535,13 @@ static irqreturn_t bfin_serial_dma_tx_int(int irq, void *dev_id)
* when start a new tx.
*/
UART_CLEAR_IER(uart, ETBEI);
- xmit->tail = (xmit->tail + uart->tx_count) & (UART_XMIT_SIZE - 1);
uart->port.icount.tx += uart->tx_count;
+ if (!uart_circ_empty(xmit)) {
+ xmit->tail = (xmit->tail + uart->tx_count) & (UART_XMIT_SIZE - 1);
- if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
- uart_write_wakeup(&uart->port);
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(&uart->port);
+ }
bfin_serial_dma_tx_chars(uart);
}