Merge tag 'firewire-update' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394

Pull firewire fix from Stefan Richter:
 "Work around JMicron initialization quirk, which ffected isochronous
  transmission, e.g. audio via FFADO or ALSA"

* tag 'firewire-update' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394:
  firewire: ohci: fix JMicron JMB38x IT context discovery

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index f51d376d10ba..c2f5117fd8cb 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -3675,6 +3675,11 @@ static int pci_probe(struct pci_dev *dev,
 
         reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, ~0);
         ohci->it_context_support = reg_read(ohci, OHCI1394_IsoXmitIntMaskSet);
+        /* JMicron JMB38x often shows 0 at first read, just ignore it */
+        if (!ohci->it_context_support) {
+                ohci_notice(ohci, "overriding IsoXmitIntMask\n");
+                ohci->it_context_support = 0xf;
+        }
         reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, ~0);
         ohci->it_context_mask = ohci->it_context_support;
         ohci->n_it = hweight32(ohci->it_context_mask);