dmaengine: qcom_hidma: add error reporting for tx_status

The HIDMA driver is capable of error detection. However, the error was
not being passed back to the client when tx_status API is called.

Changing the error handling behavior to follow this oder.

1. dmaengine asserts error interrupt
2. Driver receives and mark's the txn as error
3. Driver completes the txn and intimates the client. No further
   submissions. Drop the locks before calling callback, as subsequent
   processing by client maybe in callback thread.
4. Client invokes status and you can return error
5. On error, client calls terminate_all. You can reset channel, free all
   descriptors in the active, pending and completed lists
6. Client prepares new txn and so on.

As part of this work, got rid of the reset in the interrupt handler when
an error happens and the HW is put into disabled state. The only way to
recover is for the client to terminate the channel.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 7 insertions, 25 deletions

diff --git a/drivers/dma/qcom/hidma_ll.c b/drivers/dma/qcom/hidma_ll.c
index ad20dfb64c71..3224f24c577b 100644
--- a/drivers/dma/qcom/hidma_ll.c
+++ b/drivers/dma/qcom/hidma_ll.c
@@ -381,27 +381,6 @@ static int hidma_ll_reset(struct hidma_lldev *lldev)
 }
 
 /*
- * Abort all transactions and perform a reset.
- */
-static void hidma_ll_abort(unsigned long arg)
-{
-	struct hidma_lldev *lldev = (struct hidma_lldev *)arg;
-	u8 err_code = HIDMA_EVRE_STATUS_ERROR;
-	u8 err_info = 0xFF;
-	int rc;
-
-	hidma_cleanup_pending_tre(lldev, err_info, err_code);
-
-	/* reset the channel for recovery */
-	rc = hidma_ll_setup(lldev);
-	if (rc) {
-		dev_err(lldev->dev, "channel reinitialize failed after error\n");
-		return;
-	}
-	writel(ENABLE_IRQS, lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
-}
-
-/*
  * The interrupt handler for HIDMA will try to consume as many pending
  * EVRE from the event queue as possible. Each EVRE has an associated
  * TRE that holds the user interface parameters. EVRE reports the
@@ -454,13 +433,18 @@ irqreturn_t hidma_ll_inthandler(int chirq, void *arg)
 
 	while (cause) {
 		if (cause & HIDMA_ERR_INT_MASK) {
-			dev_err(lldev->dev, "error 0x%x, resetting...\n",
+			dev_err(lldev->dev, "error 0x%x, disabling...\n",
 					cause);
 
 			/* Clear out pending interrupts */
 			writel(cause, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG);
 
-			tasklet_schedule(&lldev->rst_task);
+			/* No further submissions. */
+			hidma_ll_disable(lldev);
+
+			/* Driver completes the txn and intimates the client.*/
+			hidma_cleanup_pending_tre(lldev, 0xFF,
+						  HIDMA_EVRE_STATUS_ERROR);
 			goto out;
 		}
 
@@ -808,7 +792,6 @@ struct hidma_lldev *hidma_ll_init(struct device *dev, u32 nr_tres,
 		return NULL;
 
 	spin_lock_init(&lldev->lock);
-	tasklet_init(&lldev->rst_task, hidma_ll_abort, (unsigned long)lldev);
 	tasklet_init(&lldev->task, hidma_ll_tre_complete, (unsigned long)lldev);
 	lldev->initialized = 1;
 	writel(ENABLE_IRQS, lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
@@ -831,7 +814,6 @@ int hidma_ll_uninit(struct hidma_lldev *lldev)
 
 	required_bytes = sizeof(struct hidma_tre) * lldev->nr_tres;
 	tasklet_kill(&lldev->task);
-	tasklet_kill(&lldev->rst_task);
 	memset(lldev->trepool, 0, required_bytes);
 	lldev->trepool = NULL;
 	lldev->pending_tre_count = 0;