diff options
| author | Peter Hurley <peter@hurleysoftware.com> | 2016-01-10 23:39:32 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-01-28 23:07:04 +0100 |
| commit | d22f8f10683c8c0f2675d9fd411a06facaf07c1b (patch) | |
| tree | 004906b39e6a6c15605246b0687a835945691ab8 /drivers/tty | |
| parent | serial: 8250: Refactor serial8250_rx_chars() inner loop (diff) | |
| download | linux-d22f8f10683c8c0f2675d9fd411a06facaf07c1b.tar.xz linux-d22f8f10683c8c0f2675d9fd411a06facaf07c1b.zip | |
serial: 8250: Fix lost rx state
When max_count is reached, the rx loop exits. However, UART_LSR has
already been read so those char flags are lost, and subsequent rx
status will be for the wrong byte until the rx fifo drains.
Reported-by: George Spelvin <linux@horizon.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/8250/8250_port.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 7580d713cde5..48680565c991 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -1478,16 +1478,17 @@ static void serial8250_read_char(struct uart_8250_port *up, unsigned char lsr) * value, and returns the remaining LSR bits not handled * by this Rx routine. */ -unsigned char -serial8250_rx_chars(struct uart_8250_port *up, unsigned char lsr) +unsigned char serial8250_rx_chars(struct uart_8250_port *up, unsigned char lsr) { struct uart_port *port = &up->port; int max_count = 256; do { serial8250_read_char(up, lsr); + if (--max_count == 0) + break; lsr = serial_in(up, UART_LSR); - } while ((lsr & (UART_LSR_DR | UART_LSR_BI)) && (--max_count > 0)); + } while (lsr & (UART_LSR_DR | UART_LSR_BI)); spin_unlock(&port->lock); tty_flip_buffer_push(&port->state->port); spin_lock(&port->lock); |