DMA complete & stop paths did not correctly account Tx'ed characters into icount.tx. Using uart_xmit_advance() fixes the problem.
Cc: stable@vger.kernel.org # serial: Create uart_xmit_advance() Fixes: e9ea096dd225 ("serial: tegra: add serial driver") Reviewed-by: Andy Shevchenko andy.shevchenko@gmail.com Signed-off-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com --- drivers/tty/serial/serial-tegra.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c index ad4f3567ff90..a5748e41483b 100644 --- a/drivers/tty/serial/serial-tegra.c +++ b/drivers/tty/serial/serial-tegra.c @@ -525,7 +525,7 @@ static void tegra_uart_tx_dma_complete(void *args) count = tup->tx_bytes_requested - state.residue; async_tx_ack(tup->tx_dma_desc); spin_lock_irqsave(&tup->uport.lock, flags); - xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1); + uart_xmit_advance(&tup->uport, count); tup->tx_in_progress = 0; if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(&tup->uport); @@ -613,7 +613,6 @@ static unsigned int tegra_uart_tx_empty(struct uart_port *u) static void tegra_uart_stop_tx(struct uart_port *u) { struct tegra_uart_port *tup = to_tegra_uport(u); - struct circ_buf *xmit = &tup->uport.state->xmit; struct dma_tx_state state; unsigned int count;
@@ -624,7 +623,7 @@ static void tegra_uart_stop_tx(struct uart_port *u) dmaengine_tx_status(tup->tx_dma_chan, tup->tx_cookie, &state); count = tup->tx_bytes_requested - state.residue; async_tx_ack(tup->tx_dma_desc); - xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1); + uart_xmit_advance(&tup->uport, count); tup->tx_in_progress = 0; }