I do not think the midlayer needs to be fixed. I think this was a bug/feature that presented itself in the 2.2 tree when we were developing this driver in 1996... Sincerely -- Mark Salyzyn > -----Original Message----- > From: Boaz Harrosh [mailto:bharrosh@xxxxxxxxxxx] > Sent: Tuesday, February 05, 2008 3:52 AM > To: Salyzyn, Mark > Cc: James Bottomley; FUJITA Tomonori; Christoph Hellwig; Jens > Axboe; Jeff Garzik; linux-scsi; Andrew Morton > Subject: Re: [PATCH 5/24][RFC] dpt_i2o: Use new scsi_eh_cpy_sense() > > On Mon, Feb 04 2008 at 20:32 +0200, "Salyzyn, Mark" > <Mark_Salyzyn@xxxxxxxxxxx> wrote: > > ACK with condition that community accepts the RFC's entire premise. > > > > The removed code that shunted the REQUEST_SENSE was based > on the assumption > > that the sense data in the current scsi command packet was > left over from the > > previous command's execution with a check condition as the > scsi command packet > > is reused to issue the REQUEST_SENSE. For a new, or second > from the target's point > > of view, request sense to the target issued by these older > kernels would always > > return an erased sense. The dpt_i2o driver does not itself > maintain the sense history, > > nor does the Firmware. This behavior, I believe, is not the > case for current kernels so > > the code fragment made little sense (pun not intended). If > my historical knowledge is > > correct, this (now removed) workaround makes no more sense > because the scsi layer correctly > > manages adapters that produce auto-request sense and does > not ever turn around the command > > and send a second request for sense information. > > > Given this understanding, I have no problem with the > removed fragment of REQUEST_SENSE shunting. > > However, I do urge some target error recovery testing, tape > drives being the likely type of target > > affected by this change. I have no such hardware to confirm... > > Sincerely -- Mark Salyzyn > > I have removed this test because the midlayer does a > scsi_eh_reset_sense() just before > the new invocation of a command. So even if the second bad > REQUEST_SENSE comes this > will not filter it out anymore. If such a thing still > happens? A driver state machine > must be used to filter it out, or of course midlayer should be fixed. > > Boaz > - 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
