diff options
| -rw-r--r-- | drivers/firewire/fw-ohci.c | 15 |
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); |