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| author | Shardar Shariff Md <smohammed@nvidia.com> | 2015-05-05 17:17:54 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-05-10 20:12:18 +0300 |
| commit | db8e78474efd5006ece9ed15d804b78ec6e70702 (patch) | |
| tree | ed3f2256688e00a766898f4a0a1cdd33fa9bad92 | |
| parent | 11e71007a5652dce2528a5d2451fe2697c6a370a (diff) | |
| download | linux-db8e78474efd5006ece9ed15d804b78ec6e70702.tar.xz | |
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>
| -rw-r--r-- | drivers/tty/serial/serial-tegra.c | 10 |
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) { |