diff options
| author | Jiri Slaby <jslaby@suse.cz> | 2022-05-03 11:08:03 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-06-09 11:23:29 +0300 |
| commit | 339ddef25f8697c0d5747634ad289f3c8188f376 (patch) | |
| tree | 0a82ea5ab580cb002b0cd69f58e93cb47ebc74d2 | |
| parent | 5607652823ac65e2c6885e73bd46d5a4f9a20363 (diff) | |
| download | linux-339ddef25f8697c0d5747634ad289f3c8188f376.tar.xz | |
serial: pch: don't overwrite xmit->buf[0] by x_char
commit d9f3af4fbb1d955bbaf872d9e76502f6e3e803cb upstream.
When x_char is to be sent, the TX path overwrites whatever is in the
circular buffer at offset 0 with x_char and sends it using
pch_uart_hal_write(). I don't understand how this was supposed to work
if xmit->buf[0] already contained some character. It must have been
lost.
Remove this whole pop_tx_x() concept and do the work directly in the
callers. (Without printing anything using dev_dbg().)
Cc: <stable@vger.kernel.org>
Fixes: 3c6a483275f4 (Serial: EG20T: add PCH_UART driver)
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220503080808.28332-1-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/serial/pch_uart.c | 27 |
1 files changed, 7 insertions, 20 deletions
diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c index f0351e6f0ef6..1e65933f6cce 100644 --- a/drivers/tty/serial/pch_uart.c +++ b/drivers/tty/serial/pch_uart.c @@ -624,22 +624,6 @@ static int push_rx(struct eg20t_port *priv, const unsigned char *buf, return 0; } -static int pop_tx_x(struct eg20t_port *priv, unsigned char *buf) -{ - int ret = 0; - struct uart_port *port = &priv->port; - - if (port->x_char) { - dev_dbg(priv->port.dev, "%s:X character send %02x (%lu)\n", - __func__, port->x_char, jiffies); - buf[0] = port->x_char; - port->x_char = 0; - ret = 1; - } - - return ret; -} - static int dma_push_rx(struct eg20t_port *priv, int size) { int room; @@ -889,9 +873,10 @@ static unsigned int handle_tx(struct eg20t_port *priv) fifo_size = max(priv->fifo_size, 1); tx_empty = 1; - if (pop_tx_x(priv, xmit->buf)) { - pch_uart_hal_write(priv, xmit->buf, 1); + if (port->x_char) { + pch_uart_hal_write(priv, &port->x_char, 1); port->icount.tx++; + port->x_char = 0; tx_empty = 0; fifo_size--; } @@ -946,9 +931,11 @@ static unsigned int dma_handle_tx(struct eg20t_port *priv) } fifo_size = max(priv->fifo_size, 1); - if (pop_tx_x(priv, xmit->buf)) { - pch_uart_hal_write(priv, xmit->buf, 1); + + if (port->x_char) { + pch_uart_hal_write(priv, &port->x_char, 1); port->icount.tx++; + port->x_char = 0; fifo_size--; } |