| commit | 4802f16d512d6e3b36177709d50c05df0ef52a6c | |
| author | Stefan Richter <stefanr@s5r6.in-berlin.de> | |
| Sun, 21 Feb 2010 16:58:52 +0000 (21 17:58 +0100) | ||
| committer | Stefan Richter <stefanr@s5r6.in-berlin.de> | |
| Wed, 24 Feb 2010 19:36:55 +0000 (24 20:36 +0100) | ||
| tree | 3d46d5088d41b8e38e7601a1a37c676d54270fe2 | treesnapshot (tar.gz zip) |
| parent | 3e9cc2f3b7ddabbbfc9abd043887030c669380aa | commitdiff |
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 <stefanr@s5r6.in-berlin.de>
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 <stefanr@s5r6.in-berlin.de>
| drivers/firewire/ohci.c | diffblobblamehistory |