mmc: dw_mmc: Make sure we don't get stuck when we get an error

[cascardo/linux.git] / drivers / mmc / host / dw_mmc.c

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 8f216ed..7f227e9 100644 (file)
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1299,6 +1299,14 @@ static void dw_mci_tasklet_func(unsigned long priv)
                        /* fall through */
 
                case STATE_SENDING_DATA:
+                       /*
+                        * We could get a data error and never a transfer
+                        * complete so we'd better check for it here.
+                        *
+                        * Note that we don't really care if we also got a
+                        * transfer complete; stopping the DMA and sending an
+                        * abort won't hurt.
+                        */
                        if (test_and_clear_bit(EVENT_DATA_ERROR,
                                               &host->pending_events)) {
                                dw_mci_stop_dma(host);
@@ -1312,7 +1320,29 @@ static void dw_mci_tasklet_func(unsigned long priv)
                                break;
 
                        set_bit(EVENT_XFER_COMPLETE, &host->completed_events);
+
+                       /*
+                        * Handle an EVENT_DATA_ERROR that might have shown up
+                        * before the transfer completed.  This might not have
+                        * been caught by the check above because the interrupt
+                        * could have gone off between the previous check and
+                        * the check for transfer complete.
+                        *
+                        * Technically this ought not be needed assuming we
+                        * get a DATA_COMPLETE eventually (we'll notice the
+                        * error and end the request), but it shouldn't hurt.
+                        *
+                        * This has the advantage of sending the stop command.
+                        */
+                       if (test_and_clear_bit(EVENT_DATA_ERROR,
+                                              &host->pending_events)) {
+                               dw_mci_stop_dma(host);
+                               send_stop_abort(host, data);
+                               state = STATE_DATA_ERROR;
+                               break;
+                       }
                        prev_state = state = STATE_DATA_BUSY;
+
                        /* fall through */
 
                case STATE_DATA_BUSY:
@@ -1335,6 +1365,22 @@ static void dw_mci_tasklet_func(unsigned long priv)
                                /* stop command for open-ended transfer*/
                                if (data->stop)
                                        send_stop_abort(host, data);
+                       } else {
+                               /*
+                                * If we don't have a command complete now we'll
+                                * never get one since we just reset everything;
+                                * better end the request.
+                                *
+                                * If we do have a command complete we'll fall
+                                * through to the SENDING_STOP command and
+                                * everything will be peachy keen.
+                                */
+                               if (!test_bit(EVENT_CMD_COMPLETE,
+                                             &host->pending_events)) {
+                                       host->cmd = NULL;
+                                       dw_mci_request_end(host, mrq);
+                                       goto unlock;
+                               }
                        }
 
                        /*