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authorVolker Ernst <volker.ernst@txtr.com>2010-10-13 11:03:57 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2010-10-22 10:20:10 -0700
commit4e4e66029af090c98cb10fafd13e8dd5039037a9 (patch)
tree3cbbbf3c4aabebc3c7ba3fc675c51956ec9f496b
parente5586eccc9aaf485985480e4d3049acffaa3fa90 (diff)
serial/imx: check that the buffer is non-empty before sending it out
The .start_tx callback (imx_start_tx here) isn't only called when the buffer is non-empty. E.g. after resume or when handshaking is enabled and the other side starts to signal being ready. So check for an empty puffer already before sending the first character. This prevents sending out stale (or uninitialised) data. Signed-off-by: Volker Ernst <volker.ernst@txtr.com> Signed-off-by: Daniel Mack <daniel@caiaq.de> Cc: Andy Green <andy@warmcat.com> [ukl: reword commit log, put check in while condition] Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/serial/imx.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/drivers/serial/imx.c b/drivers/serial/imx.c
index 66ecc7ab6da..dfcf4b1878a 100644
--- a/drivers/serial/imx.c
+++ b/drivers/serial/imx.c
@@ -327,14 +327,13 @@ static inline void imx_transmit_buffer(struct imx_port *sport)
{
struct circ_buf *xmit = &sport->port.state->xmit;
- while (!(readl(sport->port.membase + UTS) & UTS_TXFULL)) {
+ while (!uart_circ_empty(xmit) &&
+ !(readl(sport->port.membase + UTS) & UTS_TXFULL)) {
/* send xmit->buf[xmit->tail]
* out the port here */
writel(xmit->buf[xmit->tail], sport->port.membase + URTX0);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
sport->port.icount.tx++;
- if (uart_circ_empty(xmit))
- break;
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)