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Commit db8e7847 authored by Shardar Shariff Md's avatar Shardar Shariff Md Committed by Greg Kroah-Hartman
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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: default avatarShardar 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: default avatarJon Hunter <jonathanh@nvidia.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 11e71007

drivers/tty/serial/serial-tegra.c

+6 −4
Original line number Original line Diff line number Diff line
@@ -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");
@@ -588,7 +592,6 @@ 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);
@@ -626,7 +629,6 @@ 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);