dmaengine: qcom: bam_dma: Fix completed descriptors count

One space is left unused in circular FIFO to differentiate 'full' and 'empty' cases. So take that in to account while counting for the descriptors completed. Fixes the issue reported here, https://lkml.org/lkml/2019/6/18/669 Cc: [email protected] Reported-by: Srinivas Kandagatla <[email protected]> Signed-off-by: Sricharan R <[email protected]> Tested-by: Srinivas Kandagatla <[email protected]> Signed-off-by: Vinod Koul <[email protected]>
CarlFK · Jul 5, 2019 · f603422 · f603422
1 parent 3f93a4f
commit f603422
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c
@@ -799,6 +799,9 @@ static u32 process_channel_irqs(struct bam_device *bdev)
 		/* Number of bytes available to read */
 		avail = CIRC_CNT(offset, bchan->head, MAX_DESCRIPTORS + 1);
 
+		if (offset < bchan->head)
+			avail--;
+
 		list_for_each_entry_safe(async_desc, tmp,
 					 &bchan->desc_list, desc_node) {
 			/* Not enough data to read */