Commit bfc2e07f authored by Stefan Agner's avatar Stefan Agner Committed by Greg Kroah-Hartman

tty: serial: fsl_lpuart: terminate DMA on buffer flush

On uart buffer flush, serial core resets the circular buffer.
If a DMA transfer is in progress at that time, the callback
lpuart_dma_tx_complete will move buffer's tail unconditionally,
hence tail moves beyond head. Use the flush_buffer hook to
terminate the DMA imeaditely and avoid lpuart_dma_tx_complete
being called in this situation.

This bug often showed up while shutdown and lead to duplicate
serial console output.
Signed-off-by: default avatarStefan Agner <stefan@agner.ch>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 2fe605df
...@@ -455,6 +455,15 @@ static int lpuart_dma_rx(struct lpuart_port *sport) ...@@ -455,6 +455,15 @@ static int lpuart_dma_rx(struct lpuart_port *sport)
return 0; return 0;
} }
static void lpuart_flush_buffer(struct uart_port *port)
{
struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
if (sport->lpuart_dma_tx_use) {
dmaengine_terminate_all(sport->dma_tx_chan);
sport->dma_tx_in_progress = 0;
}
}
static void lpuart_dma_rx_complete(void *arg) static void lpuart_dma_rx_complete(void *arg)
{ {
struct lpuart_port *sport = arg; struct lpuart_port *sport = arg;
...@@ -1496,6 +1505,7 @@ static struct uart_ops lpuart_pops = { ...@@ -1496,6 +1505,7 @@ static struct uart_ops lpuart_pops = {
.release_port = lpuart_release_port, .release_port = lpuart_release_port,
.config_port = lpuart_config_port, .config_port = lpuart_config_port,
.verify_port = lpuart_verify_port, .verify_port = lpuart_verify_port,
.flush_buffer = lpuart_flush_buffer,
}; };
static struct uart_ops lpuart32_pops = { static struct uart_ops lpuart32_pops = {
...@@ -1514,6 +1524,7 @@ static struct uart_ops lpuart32_pops = { ...@@ -1514,6 +1524,7 @@ static struct uart_ops lpuart32_pops = {
.release_port = lpuart_release_port, .release_port = lpuart_release_port,
.config_port = lpuart_config_port, .config_port = lpuart_config_port,
.verify_port = lpuart_verify_port, .verify_port = lpuart_verify_port,
.flush_buffer = lpuart_flush_buffer,
}; };
static struct lpuart_port *lpuart_ports[UART_NR]; static struct lpuart_port *lpuart_ports[UART_NR];
......
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