From: Shardar Shariff Md <smohammed@xxxxxxxxxx>
It is only necessary to read data from the dma buffer when the count
value is non-zero and hence, tegra_uart_copy_rx_to_tty() so only be
called when this is the case.
Although, this was being tested for in two places, there is a third
place where this was not tested. However, instead of adding another
if-statement prior to calling tegra_uart_copy_rx_to_tty(), move the test
inside the function.
Signed-off-by: Shardar Shariff Md <smohammed@xxxxxxxxxx>
[jonathanh@xxxxxxxxxx: Re-worked patch to move the check for the count
value inside the function tegra_uart_copy_rx_to_tty(). Updated
changelog with more commentary.]
Signed-off-by: Jon Hunter <jonathanh@xxxxxxxxxx>
---
drivers/tty/serial/serial-tegra.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c
index 0d9d7ceb1dbb..a53899c47e60 100644
--- a/drivers/tty/serial/serial-tegra.c
+++ b/drivers/tty/serial/serial-tegra.c
@@ -554,6 +554,10 @@ static void tegra_uart_copy_rx_to_tty(struct tegra_uart_port *tup,
{
int copied;
+ /* If count is zero, then there is no data to be copied */
+ if (!count)
+ return;
+
tup->uport.icount.rx += count;
if (!tty) {
dev_err(tup->uport.dev, "No tty port\n");
@@ -588,8 +592,7 @@ static void tegra_uart_rx_dma_complete(void *args)
set_rts(tup, false);
/* If we are here, DMA is stopped */
- if (count)
- tegra_uart_copy_rx_to_tty(tup, port, count);
+ tegra_uart_copy_rx_to_tty(tup, port, count);
tegra_uart_handle_rx_pio(tup, port);
if (tty) {
@@ -626,8 +629,7 @@ static void tegra_uart_handle_rx_dma(struct tegra_uart_port *tup,
count = tup->rx_bytes_requested - state.residue;
/* If we are here, DMA is stopped */
- if (count)
- tegra_uart_copy_rx_to_tty(tup, port, count);
+ tegra_uart_copy_rx_to_tty(tup, port, count);
tegra_uart_handle_rx_pio(tup, port);
if (tty) {
--
1.9.1
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