ibmvnic: Zero used TX descriptor counter on reset

[ Upstream commit 41f714672f93608751dbd2fa2291d476a8ff0150 ]

The counter that tracks used TX descriptors pending completion
needs to be zeroed as part of a device reset. This change fixes
a bug causing transmit queues to be stopped unnecessarily and in
some cases a transmit queue stall and timeout reset. If the counter
is not reset, the remaining descriptors will not be "removed",
effectively reducing queue capacity. If the queue is over half full,
it will cause the queue to stall if stopped.

Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 6ac4dd5bb30a572546496f23611ee961a518287f..98493be7b4afedf1ad367ba6b21155ddcb25478b 100644 (file)
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -1962,6 +1962,7 @@ static int reset_one_sub_crq_queue(struct ibmvnic_adapter *adapter,
        }
 
        memset(scrq->msgs, 0, 4 * PAGE_SIZE);
+       atomic_set(&scrq->used, 0);
        scrq->cur = 0;
 
        rc = h_reg_sub_crq(adapter->vdev->unit_address, scrq->msg_token,