The hrtimer for RXDMA timeout was unconditionally restarted in the RXDMA complete handler ignoring the fact that setting up DMA may fail and PIO is used instead. Explicitly stop the timer when DMA is completed and only restart it when setting up DMA was successful. This makes the intention of the timer much clearer, the driver easier to understand and simplifies assumptions about the timer. The latter avoids race conditions if these assumptions were not met or confused. Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx> --- drivers/tty/serial/sh-sci.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 09eb0c824b10..7cc354ee6305 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1325,14 +1325,14 @@ static void sci_dma_rx_complete(void *arg) dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line, s->active_rx); + hrtimer_cancel(&s->rx_timer); + uart_port_lock_irqsave(port, &flags); active = sci_dma_rx_find_active(s); if (active >= 0) count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx); - start_hrtimer_us(&s->rx_timer, s->rx_timeout); - if (count) tty_flip_buffer_push(&port->state->port); @@ -1355,6 +1355,9 @@ static void sci_dma_rx_complete(void *arg) uart_port_unlock_irqrestore(port, flags); dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n", __func__, s->cookie_rx[active], active, s->active_rx); + + start_hrtimer_us(&s->rx_timer, s->rx_timeout); + return; fail: -- 2.43.0
