On Thu, 2010-12-23 at 17:13 +0100, Tejun Heo wrote: > On Thu, Dec 23, 2010 at 10:10:14AM -0600, James Bottomley wrote: > > > Can you please apply the debug patch I posted in the other message and > > > post the boot log? Let's see how the partition read is failing. > > > > That's actually a red herring ... the disk isn't spinning up, so the > > partition read is getting a not ready. > > Oh, yay, but at any rate I think the don't-clear-media-presence patch > is probably a good idea just in case UA gets reported somehow. Well, it wasn't this either. It turns out that this disk alone reports UNIT_ATTENTION RESET_OCCURRED on the first TEST UNIT READY of spin up. Ordinarily this is harmless, but the new medium change code wrongly interprets any UNIT_ATTENTION as medium changed (and then refuses to talk to the disk). This is actually a change from the previous code, so the fix is to put it back the way it was. James --- diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 6a88fc1..7d25746 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -1008,8 +1008,6 @@ static int media_not_present(struct scsi_disk *sdkp, /* not invoked for commands that could return deferred errors */ switch (sshdr->sense_key) { case UNIT_ATTENTION: - sdkp->device->changed = 1; - /* fall through */ case NOT_READY: /* medium not present */ if (sshdr->asc == 0x3A) { -- 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