Hi Mike, On Wednesday 20 of May 2009 at 21:57:15, Michael Krufky wrote: > I have discovered a bug in the saa7134 driver inside the function, > "saa7134_i2c_xfer" > > In order to communicate with certain i2c clients on the saa713x i2c > bus, a quirk was implemented to prevent failures during read > transactions. > > The quirk forces an i2c write/read to a bogus address that is unlikely > to be used by any i2c client. > > However, this quirk is not functioning properly. The reason for the > malfunction is that the i2c address chosen to use as the quirk address > was 0xfd. > > The address 0xfd is indeed an i2c address unlikely to be used by any > real i2c client, however, the address itself is invalid! The address, > 0xfd, has the read bit set -- this is problematic for the hardware, > and causes the quirk workaround to fail. > > It's a wonder that nobody else has complained up to this point. I had a problem with 0xfd quirk already (the presence caused the device not to respond), this is why there is an exception msgs[i].addr != 0x40 I can check if it works with your version (0xfe), but the device behind the address 0x40 (remote control) is very stupid, so I don't think so. I think that better approach would be to use the quirk only for devices (addresses) that really need it, not for all. Cheers, Oldrich. > I am asking for testers, just to make sure that this doesn't cause any > other strange errors to occur as a side effect. I don't expect any > new problems, but its always better to be safe than sorry :-) > > This change should not fix any of the other issues currently being > discussed with the saa7134 driver -- all I am asking is for people to > test and indicate that the change does not incur any NEW bugs or > unwanted behavior. > > Please test the following repository, and send in your feedback as a > reply to this thread. Please remember to keep the mailing list in cc. > > http://kernellabs.com/hg/~mk/saa7134 > > Thanks, > > Mike Krufky > -- > To unsubscribe from this list: send the line "unsubscribe linux-media" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
