Date: Wed, 23 Jul 2014 20:08:12 +0200 From: Stefan Richter Subject: firewire: ohci: disable MSI for VIA VT6315 again Revert half of commit d151f9854f21: If isochronous I/O is attempted with packets larget than 1 kByte, VIA VT6315 rev 01 immediately stops to generate any interrupts if MSI are used. Fix this by going back to legacy interrupts. [Thread "Isochronous streaming with VT6315 OHCI", http://marc.info/?t=139049641500003] With smaller packets, the loss of IRQs happens too but only very rarely --- rarely eneough that it was not yet possible for me to determine whether QUIRK_NO_MSI is an actual fix for this rare variation of this chip bug. I am keeping QUIRK_CYCLE_TIMER off of VT6315 rev >= 1 because this has been verified by myself with certainty. On the other hand, I am also keeping QUIRK_CYCLE_TIMER on for VT6315 rev 0 because I don't know at this time whether this revision accesses Cycle Timer non-atomically like most of the other VIA OHCIs are known to do. Reported-by: Rémy Bruno Signed-off-by: Stefan Richter --- drivers/firewire/ohci.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/firewire/ohci.c +++ b/drivers/firewire/ohci.c @@ -336,10 +336,10 @@ static const struct { QUIRK_CYCLE_TIMER | QUIRK_IR_WAKE}, {PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VT6315, 0, - QUIRK_CYCLE_TIMER | QUIRK_NO_MSI}, + QUIRK_CYCLE_TIMER /* FIXME: necessary? */ | QUIRK_NO_MSI}, {PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VT6315, PCI_ANY_ID, - 0}, + QUIRK_NO_MSI}, {PCI_VENDOR_ID_VIA, PCI_ANY_ID, PCI_ANY_ID, QUIRK_CYCLE_TIMER | QUIRK_NO_MSI},