[PATCH 2/9] serial: 8250_dma: Fix RX handling

From: Heikki Krogerus
Date: Wed Apr 10 2013 - 10:01:05 EST


Overrun, parity and framing errors should be handled in
8250_core. This also adds check for the dma_status and exits
if the channel is not idle.

Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
---
drivers/tty/serial/8250/8250_dma.c | 23 ++++++++++++++++-------
1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_dma.c b/drivers/tty/serial/8250/8250_dma.c
index ce2518d..6643061 100644
--- a/drivers/tty/serial/8250/8250_dma.c
+++ b/drivers/tty/serial/8250/8250_dma.c
@@ -101,20 +101,29 @@ int serial8250_rx_dma(struct uart_8250_port *p, unsigned int iir)
struct dma_tx_state state;
int dma_status;

- /*
- * If RCVR FIFO trigger level was not reached, complete the transfer and
- * let 8250.c copy the remaining data.
- */
- if ((iir & 0x3f) == UART_IIR_RX_TIMEOUT) {
- dma_status = dmaengine_tx_status(dma->rxchan, dma->rx_cookie,
- &state);
+ dma_status = dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
+
+ switch (iir & 0x3f) {
+ case UART_IIR_RLSI:
+ /* 8250_core handles errors and break interrupts */
+ return -EIO;
+ case UART_IIR_RX_TIMEOUT:
+ /*
+ * If RCVR FIFO trigger level was not reached, complete the
+ * transfer and let 8250_core copy the remaining data.
+ */
if (dma_status == DMA_IN_PROGRESS) {
dmaengine_pause(dma->rxchan);
__dma_rx_complete(p);
}
return -ETIMEDOUT;
+ default:
+ break;
}

+ if (dma_status)
+ return 0;
+
desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr,
dma->rx_size, DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
--
1.7.10.4

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