On 05/28/2010 12:34 PM, bugzilla-daemon@xxxxxxxxxxxxxxxxxxx wrote: > https://bugzilla.kernel.org/show_bug.cgi?id=16058 > > > > > > --- Comment #6 from Anonymous Emailer <anonymous@xxxxxxxxxxxxxxxxxxxx> 2010-05-28 16:34:28 --- > Reply-To: James.Bottomley@xxxxxxx > > On Fri, 2010-05-28 at 10:58 -0400, Alan Stern wrote: > >> On Fri, 28 May 2010, Mark Hounschell wrote: >> >> >>> First READ(10): >>> >>> sde: >>> ahc_calc_residual: Entered >>> ahc_calc_residual: return Case 5-1 resid = 0x800 >>> ahc_calc_residual: return Case 5-2 resid = 0x800 >>> >>> scsi_finish_command: Entered for cmd(10):0x28 0x00 0x00 0x00 0x00 0x00 >>> 0x00 0x00 0x08 0x00 >>> cmd->result = 0x00000000 >>> good_bytes == old_good_bytes = 0x800 scsi_get_resid(cmd) = 0x800 >>> New good_bytes = 0x0 >>> scsi_finish_command: Complete >>> >>> From here it just keeps repeating this read of 8 blocks. (2048 bytes) so >>> it looks like the machine is hung. >>> >> Probably not hung, just doing a lot of retries. It should time out >> eventually, but it might take a long time (perhaps as long as 15 >> minutes). The combination of the block layer and the SCSI layer isn't >> very good at knowing when to give up. >> > Actually, I think this is a partition read. Each partition manager > tends to read a page through the page cache. If we get an error, we > seem to re-read to fill the cache. > > >>> Now, I know for a fact that _if_ this read CDB is actually being sent to >>> the drive, it's actual residual count will be zero. These are working >>> disks and that read CDB is valid. >>> >>> Why is ahc_calc_residual saying that the residual count is as though the >>> read never took place? I noticed that the first read on all the SATA >>> drives was for 4096 bytes, why is this one only 2048? Should it have >>> been 4096 and ahc_calc_residual assume that? >>> >> I don't know the answer to any of these questions. They could well be >> due to bugs in the driver, and I know nothing about how the aic7xxx >> driver works. You should talk to someone who does. >> > I'll take this one ... although we're a bit lacking in documentation for > this driver. > > I think the 2048 is because something is hardcoded to think 8 sectors is > a page. > > James > > Your probably right. But is a 256 byte sector really a supported sector size for a linux fs on a SCSI disk? When it sees a 768 byte sector disk, it says it's an unsupported size and goes on with the boot process without even doing a read for a partition table. Should maybe it be doing the same for a 256 byte sector disk??? Regards Mark -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
