[PATCH AUTOSEL 4.9 17/27] net: ipa: fix a bug in ipa_endpoint_stop()

[Sasha Levin]

From: Alex Elder <elder@xxxxxxxxxx>

[ Upstream commit 713b6ebb4c376b3fb65fdceb3b59e401c93248f9 ]

In ipa_endpoint_stop(), for TX endpoints we set the number of retries
to 0.  When we break out of the loop, retries being 0 means we return
EIO rather than the value of ret (which should be 0).

Fix this by using a non-zero retry count for both RX and TX
channels, and just break out of the loop after calling
gsi_channel_stop() for TX channels.  This way only RX channels
will retry, and the retry count will be non-zero at the end
for TX channels (so the proper value gets returned).

Signed-off-by: Alex Elder <elder@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/ipa/ipa_endpoint.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ipa/ipa_endpoint.c b/drivers/net/ipa/ipa_endpoint.c
index 915b4cd05dd29..78ed431e6eb86 100644
--- a/drivers/net/ipa/ipa_endpoint.c
+++ b/drivers/net/ipa/ipa_endpoint.c
@@ -1284,7 +1284,7 @@ static int ipa_endpoint_stop_rx_dma(struct ipa *ipa)
  */
 int ipa_endpoint_stop(struct ipa_endpoint *endpoint)
 {
-	u32 retries = endpoint->toward_ipa ? 0 : IPA_ENDPOINT_STOP_RX_RETRIES;
+	u32 retries = IPA_ENDPOINT_STOP_RX_RETRIES;
 	int ret;
 
 	do {
@@ -1292,12 +1292,9 @@ int ipa_endpoint_stop(struct ipa_endpoint *endpoint)
 		struct gsi *gsi = &ipa->gsi;
 
 		ret = gsi_channel_stop(gsi, endpoint->channel_id);
-		if (ret != -EAGAIN)
+		if (ret != -EAGAIN || endpoint->toward_ipa)
 			break;
 
-		if (endpoint->toward_ipa)
-			continue;
-
 		/* For IPA v3.5.1, send a DMA read task and check again */
 		if (ipa->version == IPA_VERSION_3_5_1) {
 			ret = ipa_endpoint_stop_rx_dma(ipa);
-- 
2.20.1