On Fri, Jun 30, 2017 at 02:04:46PM +0200, Romain Perier wrote:
> From: Nandor Han <nandor.han@xxxxxx>
>
> In some cases, It looks that interrupts can happen after the dma was
s/It/it/
> disabled and port was not yet shutdown. This will result in interrupts
> handled by imx_rxint.
>
> This commits updates the shutdown function to ensure that underlying
> components are disabled in the right order. This disables RX and TX
> blocks, then it disabled interrupts. In case DMA is enabled, it disables
> DMA and free corresponding resources. It disables UART port and stop
> clocks.
>
> Signed-off-by: Nandor Han <nandor.han@xxxxxx>
> Signed-off-by: Romain Perier <romain.perier@xxxxxxxxxxxxx>
> ---
> drivers/tty/serial/imx.c | 38 +++++++++++++++++++-------------------
> 1 file changed, 19 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
> index d5b6e09..7dc6f0c 100644
> --- a/drivers/tty/serial/imx.c
> +++ b/drivers/tty/serial/imx.c
> @@ -1404,44 +1404,44 @@ static void imx_shutdown(struct uart_port *port)
> unsigned long temp;
> unsigned long flags;
>
> - if (sport->dma_is_enabled) {
> - sport->dma_is_rxing = 0;
> - sport->dma_is_txing = 0;
> - dmaengine_terminate_sync(sport->dma_chan_tx);
> - dmaengine_terminate_sync(sport->dma_chan_rx);
> -
> + if (!sport->port.suspended) {
> spin_lock_irqsave(&sport->port.lock, flags);
> imx_stop_tx(port);
> imx_stop_rx(port);
> - imx_disable_dma(sport);
> spin_unlock_irqrestore(&sport->port.lock, flags);
> - imx_uart_dma_exit(sport);
> }
>
> - mctrl_gpio_disable_ms(sport->gpios);
> + if (sport->dma_is_inited) {
> + if (sport->dma_is_enabled) {
> + spin_lock_irqsave(&sport->port.lock, flags);
> + imx_disable_dma(sport);
> + spin_unlock_irqrestore(&sport->port.lock, flags);
> + }
> + imx_uart_dma_exit(sport);
> + }
>
> spin_lock_irqsave(&sport->port.lock, flags);
> temp = readl(sport->port.membase + UCR2);
> - temp &= ~(UCR2_TXEN);
> + temp &= ~(UCR2_TXEN | UCR2_RXEN);
> writel(temp, sport->port.membase + UCR2);
> + temp = readl(sport->port.membase + UCR4);
> + temp &= ~UCR4_OREN;
> + writel(temp, sport->port.membase + UCR4);
> spin_unlock_irqrestore(&sport->port.lock, flags);
The function already had two critical blocks protected by
spin_lock_irqsave on sport->port.lock. With your patch there are three.
Is it possible to grab the lock only once?
>
> - /*
> - * Stop our timer.
> - */
> - del_timer_sync(&sport->timer);
> + mctrl_gpio_disable_ms(sport->gpios);
>
> - /*
> - * Disable all interrupts, port and break condition.
> - */
> + /* Stop our timer. */
Updating the comment style in such a commit makes the diff unnecessarily
hard to read.
> + del_timer_sync(&sport->timer);
>
> + /* Disable port. */
> spin_lock_irqsave(&sport->port.lock, flags);
> temp = readl(sport->port.membase + UCR1);
> - temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
> -
> + temp &= ~UCR1_UARTEN;
> writel(temp, sport->port.membase + UCR1);
> spin_unlock_irqrestore(&sport->port.lock, flags);
>
> + /* Disable clocks. */
> clk_disable_unprepare(sport->clk_per);
> clk_disable_unprepare(sport->clk_ipg);
> }
> --
> 1.8.3.1
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-serial" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | http://www.pengutronix.de/ |
--
To unsubscribe from this list: send the line "unsubscribe linux-serial" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
