On Sun, Nov 15, 2009 at 2:16 AM, Tejun Heo <tj@xxxxxxxxxx> wrote: > Hello, > > 11/14/2009 09:11 AM, Robert Hancock wrote: >> Luke/Tejun, do you have some error output from those wodim or growisofs >> errors? It would be useful to know what commands those were that failed >> and whether they were also an unusual data size. > > I don't have anything. For some reason, ahci works fine on the setups > here. :-( > > I'm waiting for Dan's further report. I still am not sure whether > we're actually seeing a lot of ahci ATAPI failures or it's just that a > lot of reports are on ahci because it's the most often used driver > now. I don't think anything fundamental is broken. The reports are > too infrequent for that to be true. It might have something to do > with the buffer padding / draining we do or how the controller and > driver react. >From the bug 10091 it looks like the failing command was a MODE SELECT with data transfer length of 66 bytes which is definitely odd.. My suspicion is that we're either padding out the data buffer and the indicated PRD length to a longer length than the drive actually wants to transfer, and the controller isn't happy with that, OR maybe vice-versa (i.e. we don't pad out the length and it wants us to). It's not clear if this and Jeff's issue are actually the same thing as the response is fairly different (interface fatal error and SError indications on the NV vs. a timeout on whatever chipset Jeff's using), but that may just be a chipset difference. If Jeff has a repeatable test case then that's likely the most promising place to start poking at things.. -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html