hollalinux
/
linux-sg2042
mirror of https://github.com/sophgo/linux-riscv.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

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>
This commit is contained in:
Shardar Shariff Md 2015-05-05 15:17:54 +01:00 committed by Greg Kroah-Hartman
parent 11e71007a5
commit db8e78474e
1 changed files with 6 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
drivers/tty/serial/serial-tegra.c
View File

@ -554,6 +554,10 @@ static void tegra_uart_copy_rx_to_tty(struct tegra_uart_port *tup,
{ {
int copied; int copied;
/* If count is zero, then there is no data to be copied */
if (!count)
return;
tup->uport.icount.rx += count; tup->uport.icount.rx += count;
if (!tty) { if (!tty) {
dev_err(tup->uport.dev, "No tty port\n"); 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); set_rts(tup, false);
/* If we are here, DMA is stopped */ /* 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); tegra_uart_handle_rx_pio(tup, port);
if (tty) { 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; count = tup->rx_bytes_requested - state.residue;
/* If we are here, DMA is stopped */ /* 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); tegra_uart_handle_rx_pio(tup, port);
if (tty) { if (tty) {