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Date:   Tue, 11 Jun 2019 19:33:38 +1000 (AEST)
From:   Finn Thain <fthain@telegraphics.com.au>
To:     Michael Schmitz <schmitzmic@gmail.com>
cc:     "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org,
        stable@vger.kernel.org
Subject: Re: [PATCH v2 2/7] scsi: NCR5380: Always re-enable reselection
 interrupt
In-Reply-To: <58081aba-4e77-3c8e-847e-0698cf80e426@gmail.com>
Message-ID: <alpine.LNX.2.21.1906111926330.25@nippy.intranet>
References: <cover.1560043151.git.fthain@telegraphics.com.au> <61f0c0f6aaf8fa96bf3dade5475615b2cfbc8846.1560043151.git.fthain@telegraphics.com.au> <58081aba-4e77-3c8e-847e-0698cf80e426@gmail.com>
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On Tue, 11 Jun 2019, Michael Schmitz wrote:

> Hi Finn,
> 
> IIRC I'd tested that change as well - didn't change broken target 
> behaviour but no regressions in other respects. Add my tested-by if 
> needed.
> 

Unfortunately I can't confirm that this is the same patch as the one you 
tested as I no longer have that commit. But Stan did test a wide variety 
of targets and I'm confident that the reselection code path was covered.

-- 

> Cheers,
> 
> 	Michael
> 
> 
> Am 09.06.2019 um 13:19 schrieb Finn Thain:
> > The reselection interrupt gets disabled during selection and must be
> > re-enabled when hostdata->connected becomes NULL. If it isn't re-enabled
> > a disconnected command may time-out or the target may wedge the bus while
> > trying to reselect the host. This can happen after a command is aborted.
> > 
> > Fix this by enabling the reselection interrupt in NCR5380_main() after
> > calls to NCR5380_select() and NCR5380_information_transfer() return.
> > 
> > Cc: Michael Schmitz <schmitzmic@gmail.com>
> > Cc: stable@vger.kernel.org # v4.9+
> > Fixes: 8b00c3d5d40d ("ncr5380: Implement new eh_abort_handler")
> > Tested-by: Stan Johnson <userm57@yahoo.com>
> > Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
> > ---
> >  drivers/scsi/NCR5380.c | 12 ++----------
> >  1 file changed, 2 insertions(+), 10 deletions(-)
> > 
> > diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c
> > index fe0535affc14..08e3ea8159b3 100644
> > --- a/drivers/scsi/NCR5380.c
> > +++ b/drivers/scsi/NCR5380.c
> > @@ -709,6 +709,8 @@ static void NCR5380_main(struct work_struct *work)
> >  			NCR5380_information_transfer(instance);
> >  			done = 0;
> >  		}
> > +		if (!hostdata->connected)
> > +			NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
> >  		spin_unlock_irq(&hostdata->lock);
> >  		if (!done)
> >  			cond_resched();
> > @@ -1110,8 +1112,6 @@ static bool NCR5380_select(struct Scsi_Host *instance,
> > struct scsi_cmnd *cmd)
> >  		spin_lock_irq(&hostdata->lock);
> >  		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
> >  		NCR5380_reselect(instance);
> > -		if (!hostdata->connected)
> > -			NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
> >  		shost_printk(KERN_ERR, instance, "reselection after won
> > arbitration?\n");
> >  		goto out;
> >  	}
> > @@ -1119,7 +1119,6 @@ static bool NCR5380_select(struct Scsi_Host *instance,
> > struct scsi_cmnd *cmd)
> >  	if (err < 0) {
> >  		spin_lock_irq(&hostdata->lock);
> >  		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
> > -		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
> > 
> >  		/* Can't touch cmd if it has been reclaimed by the scsi ML */
> >  		if (!hostdata->selecting)
> > @@ -1157,7 +1156,6 @@ static bool NCR5380_select(struct Scsi_Host *instance,
> > struct scsi_cmnd *cmd)
> >  	if (err < 0) {
> >  		shost_printk(KERN_ERR, instance, "select: REQ timeout\n");
> >  		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
> > -		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
> >  		goto out;
> >  	}
> >  	if (!hostdata->selecting) {
> > @@ -1826,9 +1824,6 @@ static void NCR5380_information_transfer(struct
> > Scsi_Host *instance)
> >  					 */
> >  					NCR5380_write(TARGET_COMMAND_REG, 0);
> > 
> > -					/* Enable reselect interrupts */
> > -					NCR5380_write(SELECT_ENABLE_REG,
> > hostdata->id_mask);
> > -
> >  					maybe_release_dma_irq(instance);
> >  					return;
> >  				case MESSAGE_REJECT:
> > @@ -1860,8 +1855,6 @@ static void NCR5380_information_transfer(struct
> > Scsi_Host *instance)
> >  					 */
> >  					NCR5380_write(TARGET_COMMAND_REG, 0);
> > 
> > -					/* Enable reselect interrupts */
> > -					NCR5380_write(SELECT_ENABLE_REG,
> > hostdata->id_mask);
> >  #ifdef SUN3_SCSI_VME
> >  					dregs->csr |= CSR_DMA_ENABLE;
> >  #endif
> > @@ -1964,7 +1957,6 @@ static void NCR5380_information_transfer(struct
> > Scsi_Host *instance)
> >  					cmd->result = DID_ERROR << 16;
> >  					complete_cmd(instance, cmd);
> >  					maybe_release_dma_irq(instance);
> > -					NCR5380_write(SELECT_ENABLE_REG,
> > hostdata->id_mask);
> >  					return;
> >  				}
> >  				msgout = NOP;
> > 
>