[PATCH 3.19.y-ckt 011/160] net: qca_spi: fix transmit queue timeout handling

From: Kamal Mostafa
Date: Tue Jan 19 2016 - 20:21:42 EST

3.19.8-ckt13 -stable review patch. If anyone has any objections, please let me know.


From: Stefan Wahren <stefan.wahren@xxxxxxxx>

[ Upstream commit ed7d42e24effbd3681e909711a7a2119a85e9217 ]

In case of a tx queue timeout every transmit is blocked until the
QCA7000 resets himself and triggers a sync which makes the driver
flushs the tx ring. So avoid this blocking situation by triggering
the sync immediately after the timeout. Waking the queue doesn't
make sense in this situation.

Signed-off-by: Stefan Wahren <stefan.wahren@xxxxxxxx>
Fixes: 291ab06ecf67 ("net: qualcomm: new Ethernet over SPI driver for QCA7000")
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
drivers/net/ethernet/qualcomm/qca_spi.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/qualcomm/qca_spi.c b/drivers/net/ethernet/qualcomm/qca_spi.c
index eacd476..127a35a 100644
--- a/drivers/net/ethernet/qualcomm/qca_spi.c
+++ b/drivers/net/ethernet/qualcomm/qca_spi.c
@@ -737,9 +737,8 @@ qcaspi_netdev_tx_timeout(struct net_device *dev)
netdev_info(qca->net_dev, "Transmit timeout at %ld, latency %ld\n",
jiffies, jiffies - dev->trans_start);
- /* wake the queue if there is room */
- if (qcaspi_tx_ring_has_space(&qca->txr))
- netif_wake_queue(dev);
+ /* Trigger tx queue flush and QCA7000 reset */
+ qca->sync = QCASPI_SYNC_UNKNOWN;

static int