Commit 31ca2c63 authored by Richard Genoud's avatar Richard Genoud Committed by Greg Kroah-Hartman

tty/serial: atmel: fix race condition (TX+DMA)

If uart_flush_buffer() is called between atmel_tx_dma() and
atmel_complete_tx_dma(), the circular buffer has been cleared, but not
atmel_port->tx_len.
That leads to a circular buffer overflow (dumping (UART_XMIT_SIZE -
atmel_port->tx_len) bytes).
Tested-by: default avatarNicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: default avatarRichard Genoud <richard.genoud@gmail.com>
Cc: stable <stable@vger.kernel.org> # 3.12+
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a6040bc6
...@@ -1951,6 +1951,11 @@ static void atmel_flush_buffer(struct uart_port *port) ...@@ -1951,6 +1951,11 @@ static void atmel_flush_buffer(struct uart_port *port)
atmel_uart_writel(port, ATMEL_PDC_TCR, 0); atmel_uart_writel(port, ATMEL_PDC_TCR, 0);
atmel_port->pdc_tx.ofs = 0; atmel_port->pdc_tx.ofs = 0;
} }
/*
* in uart_flush_buffer(), the xmit circular buffer has just
* been cleared, so we have to reset tx_len accordingly.
*/
atmel_port->tx_len = 0;
} }
/* /*
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment