DMA initialization error handling is not properly implemented in the
driver.
Fix DMA initialization error handling by:
- moving TX DMA descriptor request error handling in a new dedicated
fallback_err label
- adding error handling to TX DMA descriptor submission
- adding error handling to RX DMA descriptor submission
This patch depends on '24832ca3ee85 ("tty: serial: stm32-usart: Remove set
but unused 'cookie' variables")' which unfortunately doesn't include a
"Fixes" tag.
Fixes: 3489187204eb ("serial: stm32: adding dma support")
Signed-off-by: Erwan Le Ray <erwan.leray@xxxxxxxxxxx>
---
Changes in v2:
- delete DMA cookie variables removal from V1 patch as already done by a
previous patch
- update commit message as DMA cookie variables removal is no more
included in this patch
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index f4de32d3f2af..6248304a001f 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -383,17 +383,18 @@ static void stm32_transmit_chars_dma(struct uart_port *port)
DMA_MEM_TO_DEV,
DMA_PREP_INTERRUPT);
- if (!desc) {
- for (i = count; i > 0; i--)
- stm32_transmit_chars_pio(port);
- return;
- }
+ if (!desc)
+ goto fallback_err;
desc->callback = stm32_tx_dma_complete;
desc->callback_param = port;
/* Push current DMA TX transaction in the pending queue */
- dmaengine_submit(desc);
+ if (dma_submit_error(dmaengine_submit(desc))) {
+ /* dma no yet started, safe to free resources */
+ dmaengine_terminate_async(stm32port->tx_ch);
+ goto fallback_err;
+ }
/* Issue pending DMA TX requests */
dma_async_issue_pending(stm32port->tx_ch);
@@ -402,6 +403,11 @@ static void stm32_transmit_chars_dma(struct uart_port *port)
xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
port->icount.tx += count;
+ return;
+
+fallback_err:
+ for (i = count; i > 0; i--)
+ stm32_transmit_chars_pio(port);
}
static void stm32_transmit_chars(struct uart_port *port)
@@ -1130,7 +1136,11 @@ static int stm32_of_dma_rx_probe(struct stm32_port *stm32port,
desc->callback_param = NULL;
/* Push current DMA transaction in the pending queue */
- dmaengine_submit(desc);
+ ret = dma_submit_error(dmaengine_submit(desc));
+ if (ret) {
+ dmaengine_terminate_sync(stm32port->rx_ch);
+ goto config_err;
+ }
/* Issue pending DMA requests */
dma_async_issue_pending(stm32port->rx_ch);
--
2.17.1
