1 files changed, 13 insertions, 2 deletions

diff --git a/drivers/firewire/fw-ohci.c b/drivers/firewire/fw-ohci.c
index ce18bab3f9d5..4789300b8241 100644
--- a/drivers/firewire/fw-ohci.c
+++ b/drivers/firewire/fw-ohci.c
@@ -950,8 +950,19 @@ at_context_queue_packet(struct context *ctx, struct fw_packet *packet)
                                      DESCRIPTOR_IRQ_ALWAYS |
                                      DESCRIPTOR_BRANCH_ALWAYS);
 
-        /* FIXME: Document how the locking works. */
-        if (ohci->generation != packet->generation) {
+        /*
+         * If the controller and packet generations don't match, we need to
+         * bail out and try again.  If IntEvent.busReset is set, the AT context
+         * is halted, so appending to the context and trying to run it is
+         * futile.  Most controllers do the right thing and just flush the AT
+         * queue (per section 7.2.3.2 of the OHCI 1.1 specification), but
+         * 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: Document how the locking works.
+         */
+        if (ohci->generation != packet->generation ||
+            reg_read(ohci, OHCI1394_IntEventSet) & OHCI1394_busReset) {
                 if (packet->payload_length > 0)
                         dma_unmap_single(ohci->card.device, payload_bus,
                                          packet->payload_length, DMA_TO_DEVICE);