spi: Add a timeout when waiting for transfers

Don't wait indefinitely for transfers to complete but time out after 10ms
more than we expect the transfer to take on the wire.

Signed-off-by: Mark Brown <broonie@linaro.org>

1 files changed, 11 insertions, 1 deletions

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 23756b0f9036..516643d243c6 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -594,6 +594,7 @@ static int spi_transfer_one_message(struct spi_master *master,
         bool cur_cs = true;
         bool keep_cs = false;
         int ret = 0;
+        int ms = 1;
 
         spi_set_cs(msg->spi, true);
 
@@ -611,7 +612,16 @@ static int spi_transfer_one_message(struct spi_master *master,
 
                 if (ret > 0) {
                         ret = 0;
-                        wait_for_completion(&master->xfer_completion);
+                        ms = xfer->len * 8 * 1000 / xfer->speed_hz;
+                        ms += 10; /* some tolerance */
+
+                        ms = wait_for_completion_timeout(&master->xfer_completion,
+                                                         msecs_to_jiffies(ms));
+                }
+
+                if (ms == 0) {
+                        dev_err(&msg->spi->dev, "SPI transfer timed out\n");
+                        msg->status = -ETIMEDOUT;
                 }
 
                 trace_spi_transfer_stop(msg, xfer);