Re: [PATCH/RFT] libata "DMA timeout" fix

[Jeff Garzik]

James Bottomley wrote:
> On Sat, 2004-02-28 at 13:10, Jeff Garzik wrote:
>
> > ===== drivers/scsi/libata-core.c 1.19 vs edited =====
> > --- 1.19/drivers/scsi/libata-core.c	Wed Feb 25 22:41:13 2004
> > +++ edited/drivers/scsi/libata-core.c	Sat Feb 28 14:03:18 2004
> > @@ -2130,6 +2130,14 @@
> > 				cmd->result = SAM_STAT_CHECK_CONDITION;
> > 			else
> > 				ata_to_sense_error(qc);
> > +
> > +			/* hack alert! we need this to get past the
> > +			 * first check in scsi_done().  libata is the
> > +			 * -only- user of ->eh_strategy_handler() in
> > +			 * any kernel tree, which exposes some incorrect
> > +			 * assumptions in the SCSI layer.
> > +			 */
> > +			scsi_add_timer(cmd, 2000 * HZ, NULL);
> > 		} else {
> > 			cmd->result = SAM_STAT_GOOD;
> > 		}
>
>
> You can't do this.  Supposing there command's delayed, the timer fires
> and then the command returns with a sense error?  The done will go
> through automatically completing the command, but your strategy handler
> will still think it has a failed command to handle.

hmmm, yeah that will be a problem iff we are not already in the strategy 
handler.


> The correct fix is this, I think (uncompiled, but you get the idea):

Yeah, that's much better.  That function is not exported though ;-)

	Jeff



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