aic94xx: fix sequencer hang on error recovery

aic94xx: fix sequencer hang on error recovery

[James Bottomley]

The clear nexus I_T and clear nexus I_T_L functions in the aic94xx
specify the SUSPEND_TX flag which causes the sequencer to be suspended
until it receives a RESUME_TX.  Unfortunately, nothing ever sends the
resume, so the sequencer on the link is stopped forever, leading to
eventual timeouts and I/O errors.

Since clear nexus commands are only executed as part of error recovery,
it's perfectly fine to keep the sequencer running on the link ... as
soon as the recovery function is completed, we'll send it the commands
to retry.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

---

diff --git a/drivers/scsi/aic94xx/aic94xx_tmf.c b/drivers/scsi/aic94xx/aic94xx_tmf.c
index b52124f..144f5ad 100644
--- a/drivers/scsi/aic94xx/aic94xx_tmf.c
+++ b/drivers/scsi/aic94xx/aic94xx_tmf.c
@@ -151,8 +151,6 @@ static int asd_clear_nexus_I_T(struct domain_device *dev)
 	CLEAR_NEXUS_PRE;
 	scb->clear_nexus.nexus = NEXUS_I_T;
 	scb->clear_nexus.flags = SEND_Q | EXEC_Q | NOTINQ;
-	if (dev->tproto)
-		scb->clear_nexus.flags |= SUSPEND_TX;
 	scb->clear_nexus.conn_handle = cpu_to_le16((u16)(unsigned long)
 						   dev->lldd_dev);
 	CLEAR_NEXUS_POST;
@@ -169,8 +167,6 @@ static int asd_clear_nexus_I_T_L(struct domain_device *dev, u8 *lun)
 	CLEAR_NEXUS_PRE;
 	scb->clear_nexus.nexus = NEXUS_I_T_L;
 	scb->clear_nexus.flags = SEND_Q | EXEC_Q | NOTINQ;
-	if (dev->tproto)
-		scb->clear_nexus.flags |= SUSPEND_TX;
 	memcpy(scb->clear_nexus.ssp_task.lun, lun, 8);
 	scb->clear_nexus.conn_handle = cpu_to_le16((u16)(unsigned long)
 						   dev->lldd_dev);

Re: aic94xx: fix sequencer hang on error recovery

[Luben Tuikov]

--- On Fri, 2/22/08, James Bottomley <James.Bottomley@HansenPartnership.com> wrote:
> The clear nexus I_T and clear nexus I_T_L functions in the
> aic94xx
> specify the SUSPEND_TX flag which causes the sequencer to
> be suspended
> until it receives a RESUME_TX.  Unfortunately, nothing ever
> sends the
> resume, so the sequencer on the link is stopped forever,
> leading to
> eventual timeouts and I/O errors.
> 
> Since clear nexus commands are only executed as part of
> error recovery,
> it's perfectly fine to keep the sequencer running on
> the link ... as
> soon as the recovery function is completed, we'll send
> it the commands
> to retry.

No, this doesn't seem right.

   Luben

> Signed-off-by: James Bottomley
> <James.Bottomley@HansenPartnership.com>
> 
> ---
> 
> diff --git a/drivers/scsi/aic94xx/aic94xx_tmf.c
> b/drivers/scsi/aic94xx/aic94xx_tmf.c
> index b52124f..144f5ad 100644
> --- a/drivers/scsi/aic94xx/aic94xx_tmf.c
> +++ b/drivers/scsi/aic94xx/aic94xx_tmf.c
> @@ -151,8 +151,6 @@ static int asd_clear_nexus_I_T(struct
> domain_device *dev)
>  	CLEAR_NEXUS_PRE;
>  	scb->clear_nexus.nexus = NEXUS_I_T;
>  	scb->clear_nexus.flags = SEND_Q | EXEC_Q | NOTINQ;
> -	if (dev->tproto)
> -		scb->clear_nexus.flags |= SUSPEND_TX;
>  	scb->clear_nexus.conn_handle =
> cpu_to_le16((u16)(unsigned long)
>  						   dev->lldd_dev);
>  	CLEAR_NEXUS_POST;
> @@ -169,8 +167,6 @@ static int asd_clear_nexus_I_T_L(struct
> domain_device *dev, u8 *lun)
>  	CLEAR_NEXUS_PRE;
>  	scb->clear_nexus.nexus = NEXUS_I_T_L;
>  	scb->clear_nexus.flags = SEND_Q | EXEC_Q | NOTINQ;
> -	if (dev->tproto)
> -		scb->clear_nexus.flags |= SUSPEND_TX;
>  	memcpy(scb->clear_nexus.ssp_task.lun, lun, 8);
>  	scb->clear_nexus.conn_handle =
> cpu_to_le16((u16)(unsigned long)
>  						   dev->lldd_dev);
> 
> 
> -
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