firewire: ohci: flush AT contexts after bus reset - addendum
Add comments
- on why bus_reset_tasklet flushes AT queues,
- that commit 76f73ca1b291 can possibly be reverted now.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: Jarod Wilson <jarod@redhat.com>
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 3372cd1..cfe5afe 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -1336,6 +1336,8 @@
* some controllers (like a JMicron JMB381 PCI-e) misbehave and wind
* up stalling out. So we just bail out in software and try again
* later, and everyone is happy.
+ * FIXME: Test of IntEvent.busReset may no longer be necessary since we
+ * flush AT queues in bus_reset_tasklet.
* FIXME: Document how the locking works.
*/
if (ohci->generation != packet->generation ||
@@ -1750,6 +1752,11 @@
spin_unlock_irqrestore(&ohci->lock, flags);
+ /*
+ * Per OHCI 1.2 draft, clause 7.2.3.3, hardware may leave unsent
+ * packets in the AT queues and software needs to drain them.
+ * Some OHCI 1.1 controllers (JMicron) apparently require this too.
+ */
at_context_flush(&ohci->at_request_ctx);
at_context_flush(&ohci->at_response_ctx);