Re: [PATCH v1 1/5] scsi: Adjust DBD setting in mode sense for caching mode page per LLD

[cang]

On 2019-10-28 22:58, Bart Van Assche wrote:
> On 10/27/19 8:50 PM, Can Guo wrote:
> > Host sends MODE_SENSE_10 with caching mode page, to check if the 
> > device
> > supports the cache feature.
> > Some LLD standards requires DBD field to be set to 1.
>
> Which LLD standard are you referring to? Please mention at least one
> name of such a standard in the patch description.

Hi Bart, Thank you for your review.

The LLD standard here is UFS. I will update the commit message and 
re-upload it later.

Thanks,

Can Guo

> > Change-Id: I0c8752c1888654942d6d7e6e0f6dc197033ac326
>
> Change-IDs should be left out from upstream patches. Does the presence
> of this ID mean that this patch has not been verified with checkpatch?
> From the checkpatch source code:
>
> # Check for unwanted Gerrit info
> if ($in_commit_log && $line =~ /^\s*change-id:/i) {
> 	ERROR("GERRIT_CHANGE_ID",
> 	      "Remove Gerrit Change-Id's before submitting upstream.\n"\
> 		 . $herecurr);
> }

Sorry, forgot to remove the change-id.

> > diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
> > index aab4ed8..6d8194f 100644
> > --- a/drivers/scsi/sd.c
> > +++ b/drivers/scsi/sd.c
> > @@ -2629,6 +2629,7 @@ static int sd_try_rc16_first(struct scsi_device 
> > *sdp)
> >   {
> >   	int len = 0, res;
> >   	struct scsi_device *sdp = sdkp->device;
> > +	struct Scsi_Host *host = sdp->host;
> >     	int dbd;
> >   	int modepage;
> > @@ -2660,7 +2661,10 @@ static int sd_try_rc16_first(struct scsi_device 
> > *sdp)
> >   		dbd = 8;
> >   	} else {
> >   		modepage = 8;
> > -		dbd = 0;
> > +		if (host->set_dbd_for_caching)
> > +			dbd = 8;
> > +		else
> > +			dbd = 0;
> >   	}
> >     	/* cautiously ask */
> > diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
> > index 2c3f0c5..3900987 100644
> > --- a/include/scsi/scsi_host.h
> > +++ b/include/scsi/scsi_host.h
> > @@ -650,6 +650,12 @@ struct Scsi_Host {
> >   	unsigned no_scsi2_lun_in_cdb:1;
> >     	/*
> > +	 * Set "DBD" field in mode_sense caching mode page in case it is
> > +	 * mandatory by LLD standard.
> > +	 */
> > +	unsigned set_dbd_for_caching:1;
> > +
> > +	/*
> >   	 * Optional work queue to be utilized by the transport
> >   	 */
> >   	char work_q_name[20];
>
> Since this patch by itself has no effect, please resubmit this patch
> together with the LLD patch that sets set_dbd_for_caching.
>
> Thanks,
>
> Bart.