firewire: ohci: optimize iso context checks in the interrupt handler
When the isochRx/isochTx bit is clear, we do not need to read the
corresponding iso interrupt event register.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 29259f3..01b3bc9 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -1813,22 +1813,28 @@
if (event & OHCI1394_respTxComplete)
tasklet_schedule(&ohci->at_response_ctx.tasklet);
- iso_event = reg_read(ohci, OHCI1394_IsoRecvIntEventClear);
- reg_write(ohci, OHCI1394_IsoRecvIntEventClear, iso_event);
+ if (event & OHCI1394_isochRx) {
+ iso_event = reg_read(ohci, OHCI1394_IsoRecvIntEventClear);
+ reg_write(ohci, OHCI1394_IsoRecvIntEventClear, iso_event);
- while (iso_event) {
- i = ffs(iso_event) - 1;
- tasklet_schedule(&ohci->ir_context_list[i].context.tasklet);
- iso_event &= ~(1 << i);
+ while (iso_event) {
+ i = ffs(iso_event) - 1;
+ tasklet_schedule(
+ &ohci->ir_context_list[i].context.tasklet);
+ iso_event &= ~(1 << i);
+ }
}
- iso_event = reg_read(ohci, OHCI1394_IsoXmitIntEventClear);
- reg_write(ohci, OHCI1394_IsoXmitIntEventClear, iso_event);
+ if (event & OHCI1394_isochTx) {
+ iso_event = reg_read(ohci, OHCI1394_IsoXmitIntEventClear);
+ reg_write(ohci, OHCI1394_IsoXmitIntEventClear, iso_event);
- while (iso_event) {
- i = ffs(iso_event) - 1;
- tasklet_schedule(&ohci->it_context_list[i].context.tasklet);
- iso_event &= ~(1 << i);
+ while (iso_event) {
+ i = ffs(iso_event) - 1;
+ tasklet_schedule(
+ &ohci->it_context_list[i].context.tasklet);
+ iso_event &= ~(1 << i);
+ }
}
if (unlikely(event & OHCI1394_regAccessFail))