On Wed, 2021-07-14 at 01:20 +0300, Andy Shevchenko wrote:

On Saturday, July 10, 2021, Zhiyong Tao [off-list ref]
wrote:


Please, use “serial: 8260_mtk:” prefix.

==> Hi Andy,

Thanks for your suggestion.
we will change it in the next version.

        This patch is used to fix memory 
        


This is completely confusing start of the sentence. The form of “be
used to” strongly suggests two things: 1) it was a patch to fix
something; 2) it is not used anymore and never considered to be used
again,


Besides that Submitting Patches document highly recommends to avoid
sentences that starts with “this patch”.
 

==>We will change the commit message as "Fix uart corruption issue when
rx power off "in the next version.

Thanks.

        
        corruption issue when rx power off.
        1. add spin lock in mtk8250_dma_rx_complete function in APDMA
        mode.
        2. add processing mechanism which count value is 0
        
        Signed-off-by: Zhiyong Tao [off-list ref]
        ---
         drivers/tty/serial/8250/8250_mtk.c | 15 +++++++++++----
         1 file changed, 11 insertions(+), 4 deletions(-)
        
        diff --git a/drivers/tty/serial/8250/8250_mtk.c
        b/drivers/tty/serial/8250/8250_mtk.c
        index f7d3023f860f..09f7d2166315 100644
        --- a/drivers/tty/serial/8250/8250_mtk.c
        +++ b/drivers/tty/serial/8250/8250_mtk.c
        @@ -91,12 +91,15 @@ static void mtk8250_dma_rx_complete(void
        *param)
                struct mtk8250_data *data = up->port.private_data;
                struct tty_port *tty_port = &up->port.state->port;
                struct dma_tx_state state;
        -       int copied, total, cnt;
        +       unsigned int copied, total, cnt;
                unsigned char *ptr;
        +       unsigned long flags;
        
                if (data->rx_status == DMA_RX_SHUTDOWN)
                        return;
        
        +       spin_lock_irqsave(&up->port.lock, flags);
        +
                dmaengine_tx_status(dma->rxchan, dma->rx_cookie,
        &state);
                total = dma->rx_size - state.residue;
                cnt = total;
        @@ -104,9 +107,11 @@ static void mtk8250_dma_rx_complete(void
        *param)
                if ((data->rx_pos + cnt) > dma->rx_size)
                        cnt = dma->rx_size - data->rx_pos;
        
        -       ptr = (unsigned char *)(data->rx_pos + dma->rx_buf);
        -       copied = tty_insert_flip_string(tty_port, ptr, cnt);
        -       data->rx_pos += cnt;
        +       if (cnt != 0) {
        +               ptr = (unsigned char *)(data->rx_pos +
        dma->rx_buf);
        +               copied = tty_insert_flip_string(tty_port, ptr,
        cnt);
        +               data->rx_pos += cnt;
        +       }
        
                if (total > cnt) {
                        ptr = (unsigned char *)(dma->rx_buf);
        @@ -120,6 +125,8 @@ static void mtk8250_dma_rx_complete(void
        *param)
                tty_flip_buffer_push(tty_port);
        
                mtk8250_rx_dma(up);
        +
        +       spin_unlock_irqrestore(&up->port.lock, flags);
         }
        
         static void mtk8250_rx_dma(struct uart_8250_port *up)