xen/netback: fix spurious event detection for common event case

[ Upstream commit a3daf3d391 ]

In case of a common event for rx and tx queue the event should be
regarded to be spurious if no rx and no tx requests are pending.

Unfortunately the condition for testing that is wrong causing to
decide a event being spurious if no rx OR no tx requests are
pending.

Fix that plus using local variables for rx/tx pending indicators in
order to split function calls and if condition.

Fixes: 23025393db ("xen/netback: use lateeoi irq binding")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: Wei Liu <wl@xen.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Juergen Gross 2021-02-11 11:16:12 +01:00 committed by Greg Kroah-Hartman
parent 5c54aaed07
commit fef6f594ea

View file

@ -162,13 +162,15 @@ irqreturn_t xenvif_interrupt(int irq, void *dev_id)
{
struct xenvif_queue *queue = dev_id;
int old;
bool has_rx, has_tx;
old = atomic_fetch_or(NETBK_COMMON_EOI, &queue->eoi_pending);
WARN(old, "Interrupt while EOI pending\n");
/* Use bitwise or as we need to call both functions. */
if ((!xenvif_handle_tx_interrupt(queue) |
!xenvif_handle_rx_interrupt(queue))) {
has_tx = xenvif_handle_tx_interrupt(queue);
has_rx = xenvif_handle_rx_interrupt(queue);
if (!has_rx && !has_tx) {
atomic_andnot(NETBK_COMMON_EOI, &queue->eoi_pending);
xen_irq_lateeoi(irq, XEN_EOI_FLAG_SPURIOUS);
}