gve: Remove the code of clearing PBA bit

[ Upstream commit f4c2e67 ]

Clearing the PBA bit from the driver is race prone and it may lead to
dropped interrupt events. This could potentially lead to the traffic
being completely halted.

Fixes: 5e8c5ad ("gve: DQO: Add core netdev features")
Signed-off-by: Ziwei Xiao <ziweixiao@google.com>
Signed-off-by: Bailey Forrest <bcf@google.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/net/ethernet/google/gve/gve_main.c

@@ -284,19 +284,6 @@ static int gve_napi_poll_dqo(struct napi_struct *napi, int budget)
 	bool reschedule = false;
 	int work_done = 0;
 
-	/* Clear PCI MSI-X Pending Bit Array (PBA)
-	 *
-	 * This bit is set if an interrupt event occurs while the vector is
-	 * masked. If this bit is set and we reenable the interrupt, it will
-	 * fire again. Since we're just about to poll the queue state, we don't
-	 * need it to fire again.
-	 *
-	 * Under high softirq load, it's possible that the interrupt condition
-	 * is triggered twice before we got the chance to process it.
-	 */
-	gve_write_irq_doorbell_dqo(priv, block,
-				   GVE_ITR_NO_UPDATE_DQO | GVE_ITR_CLEAR_PBA_BIT_DQO);
-
 	if (block->tx)
 		reschedule |= gve_tx_poll_dqo(block, /*do_clean=*/true);