From: Sricharan R <sricharan@codeaurora.org>
Date: Fri, 28 Jun 2019 12:09:46 +0000 (+0530)
Subject: dmaengine: qcom: bam_dma: Fix completed descriptors count
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=f6034225442c4a87906d36e975fd9e99a8f95487;p=openwrt%2Fstaging%2Fblogic.git

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: stable@vger.kernel.org
Reported-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
---

diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c
index 4b43844f6af5..8e90a405939d 100644
--- 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 */