From f6034225442c4a87906d36e975fd9e99a8f95487 Mon Sep 17 00:00:00 2001
From: Sricharan R <sricharan@codeaurora.org>
Date: Fri, 28 Jun 2019 17:39:46 +0530
Subject: [PATCH] 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>
---
drivers/dma/qcom/bam_dma.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c
index 4b43844f6af53..8e90a405939df 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 */
--
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