dmaengine: edma: Simplify and optimize ccerr interrupt handler

No need to run through the bits in QEMR and CCERR events since they will
not trigger any action, so just clearing the errors there is fine.
In case of the missed event the loop can be optimized so we spend less time
to handle the event.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/edma.c

@@ -1640,9 +1640,10 @@ static inline bool edma_error_pending(struct edma_cc *ecc)
 static irqreturn_t dma_ccerr_handler(int irq, void *data)
 {
 	struct edma_cc *ecc = data;
-	int i;
+	int i, j;
 	int ctlr;
 	unsigned int cnt = 0;
+	unsigned int val;
 
 	ctlr = ecc->id;
 	if (ctlr < 0)
@@ -1654,57 +1655,44 @@ static irqreturn_t dma_ccerr_handler(int irq, void *data)
 		return IRQ_NONE;
 
 	while (1) {
-		int j = -1;
+		/* Event missed register(s) */
+		for (j = 0; j < 2; j++) {
+			unsigned long emr;
 
-		if (edma_read_array(ecc, EDMA_EMR, 0))
-			j = 0;
-		else if (edma_read_array(ecc, EDMA_EMR, 1))
-			j = 1;
-		if (j >= 0) {
-			dev_dbg(ecc->dev, "EMR%d %08x\n", j,
-				edma_read_array(ecc, EDMA_EMR, j));
-			for (i = 0; i < 32; i++) {
+			val = edma_read_array(ecc, EDMA_EMR, j);
+			if (!val)
+				continue;
+
+			dev_dbg(ecc->dev, "EMR%d 0x%08x\n", j, val);
+			emr = val;
+			for (i = find_next_bit(&emr, 32, 0); i < 32;
+			     i = find_next_bit(&emr, 32, i + 1)) {
 				int k = (j << 5) + i;
 
-				if (edma_read_array(ecc, EDMA_EMR, j) &
-							BIT(i)) {
 				/* Clear the corresponding EMR bits */
-					edma_write_array(ecc, EDMA_EMCR, j,
-							 BIT(i));
+				edma_write_array(ecc, EDMA_EMCR, j, BIT(i));
 				/* Clear any SER */
-					edma_shadow0_write_array(ecc, SH_SECR,
-								 j, BIT(i));
+				edma_shadow0_write_array(ecc, SH_SECR, j,
+							 BIT(i));
 				edma_error_handler(&ecc->slave_chans[k]);
 			}
 		}
-		} else if (edma_read(ecc, EDMA_QEMR)) {
-			dev_dbg(ecc->dev, "QEMR %02x\n",
-				edma_read(ecc, EDMA_QEMR));
-			for (i = 0; i < 8; i++) {
-				if (edma_read(ecc, EDMA_QEMR) & BIT(i)) {
-					/* Clear the corresponding IPR bits */
-					edma_write(ecc, EDMA_QEMCR, BIT(i));
-					edma_shadow0_write(ecc, SH_QSECR,
-							   BIT(i));
 
-					/* NOTE:  not reported!! */
+		val = edma_read(ecc, EDMA_QEMR);
+		if (val) {
+			dev_dbg(ecc->dev, "QEMR 0x%02x\n", val);
+			/* Not reported, just clear the interrupt reason. */
+			edma_write(ecc, EDMA_QEMCR, val);
+			edma_shadow0_write(ecc, SH_QSECR, val);
 		}
-			}
-		} else if (edma_read(ecc, EDMA_CCERR)) {
-			dev_dbg(ecc->dev, "CCERR %08x\n",
-				edma_read(ecc, EDMA_CCERR));
-			/* FIXME:  CCERR.BIT(16) ignored!  much better
-			 * to just write CCERRCLR with CCERR value...
-			 */
-			for (i = 0; i < 8; i++) {
-				if (edma_read(ecc, EDMA_CCERR) & BIT(i)) {
-					/* Clear the corresponding IPR bits */
-					edma_write(ecc, EDMA_CCERRCLR, BIT(i));
 
-					/* NOTE:  not reported!! */
-				}
-			}
+		val = edma_read(ecc, EDMA_CCERR);
+		if (val) {
+			dev_warn(ecc->dev, "CCERR 0x%08x\n", val);
+			/* Not reported, just clear the interrupt reason. */
+			edma_write(ecc, EDMA_CCERRCLR, val);
 		}
+
 		if (!edma_error_pending(ecc))
 			break;
 		cnt++;