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 <remy-fw@remy.trinnov.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 5b0934d..41df806 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -336,10 +336,10 @@
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},