Date: Sun, 21 Feb 2010 17:58:52 +0100 (CET) From: Stefan Richter Subject: firewire: ohci: fix IR/IT context mask mixup This bug was present in firewire-ohci since day one: The number of available isochronous receive DMA contexts was mixed up with that of available isochronous transmit DMA contexts. This is harmless on a few chips which offer the same number of contexts in both directions, but most chips nowadays implement only the standard minimum of 4 IR contexts, but 8 IT contexts. If a user attempted to run a lot of IR contexts at once, results with more than four were therefore unpredictable. I suppose the controller would simply refuse to start DMA of any unimplemented context. Signed-off-by: Stefan Richter --- drivers/firewire/ohci.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) Index: b/drivers/firewire/ohci.c =================================================================== --- a/drivers/firewire/ohci.c +++ b/drivers/firewire/ohci.c @@ -2395,17 +2395,17 @@ static int __devinit pci_probe(struct pc OHCI1394_AsRspTrContextControlSet, handle_at_packet); reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, ~0); - ohci->it_context_mask = reg_read(ohci, OHCI1394_IsoRecvIntMaskSet); + ohci->ir_context_channels = ~0ULL; + ohci->ir_context_mask = reg_read(ohci, OHCI1394_IsoRecvIntMaskSet); reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, ~0); - size = sizeof(struct iso_context) * hweight32(ohci->it_context_mask); - ohci->it_context_list = kzalloc(size, GFP_KERNEL); + size = sizeof(struct iso_context) * hweight32(ohci->ir_context_mask); + ohci->ir_context_list = kzalloc(size, GFP_KERNEL); reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, ~0); - ohci->ir_context_channels = ~0ULL; - ohci->ir_context_mask = reg_read(ohci, OHCI1394_IsoXmitIntMaskSet); + ohci->it_context_mask = reg_read(ohci, OHCI1394_IsoXmitIntMaskSet); reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, ~0); - size = sizeof(struct iso_context) * hweight32(ohci->ir_context_mask); - ohci->ir_context_list = kzalloc(size, GFP_KERNEL); + size = sizeof(struct iso_context) * hweight32(ohci->it_context_mask); + ohci->it_context_list = kzalloc(size, GFP_KERNEL); if (ohci->it_context_list == NULL || ohci->ir_context_list == NULL) { err = -ENOMEM;