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authorShardar Shariff Md <smohammed@nvidia.com>2015-05-05 16:17:54 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-05-10 19:12:18 +0200
commitdb8e78474efd5006ece9ed15d804b78ec6e70702 (patch)
treeed3f2256688e00a766898f4a0a1cdd33fa9bad92 /drivers/tty/serial/serial-tegra.c
parentserial: tegra: Add delay after enabling FIFO mode (diff)
downloadlinux-db8e78474efd5006ece9ed15d804b78ec6e70702.tar.xz
linux-db8e78474efd5006ece9ed15d804b78ec6e70702.zip
serial: tegra: check the count and read if any from dma
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@nvidia.com> [jonathanh@nvidia.com: 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@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to '')
-rw-r--r--drivers/tty/serial/serial-tegra.c10
1 files 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) {