On Sun, Jun 3, 2018 at 3:21 AM Stanislav Nijnikov <Stanislav.Nijnikov@xxxxxxx> wrote: > > > > > -----Original Message----- > > From: linux-scsi-owner@xxxxxxxxxxxxxxx <linux-scsi-owner@xxxxxxxxxxxxxxx> On Behalf Of Evan Green > > Sent: Friday, June 1, 2018 5:44 PM > > To: Stanislav Nijnikov <Stanislav.Nijnikov@xxxxxxx> > > Cc: Vinayak Holikatti <vinholikatti@xxxxxxxxx>; jejb@xxxxxxxxxxxxxxxxxx; martin.petersen@xxxxxxxxxx; linux- > > kernel@xxxxxxxxxxxxxxx; linux-scsi@xxxxxxxxxxxxxxx; Gwendal Grignou <gwendal@xxxxxxxxxxxx>; Alex Lemberg > > <Alex.Lemberg@xxxxxxx>; Avri Altman <Avri.Altman@xxxxxxx> > > Subject: Re: [PATCH 0/7] Enable UFS provisioning via Linux > > > > Hi Stanislav. Thanks for taking a look. Responses below. > > > > On Thu, May 31, 2018 at 3:04 AM Stanislav Nijnikov > > <Stanislav.Nijnikov@xxxxxxx> wrote: > > > > > > Hi Evan, > > > I have some generic notes: > > > - Why to create new sysfs entries for the configuration descriptor fields if they are just duplication of fields in the device and unit > > descriptors? And the sysfs representation of the device and unit descriptors is existing already. > > > > Well, UFS describes them as different descriptors. I worry that if I > > add a bunch of clever logic to hide the config descriptor behind other > > descriptors, there might be trouble later if 1) there is a quirky > > device that doesn't reflect the values between descriptors quite the > > same way or at the same time, or 2) if a later UFS spec adds more > > configuration descriptor fields that don't exactly reflect into other > > non-config descriptors, the cleverness will look awkward. > > No additional logic will be required to attach write functionality to the > existing entries instead of new defined ones. It will reduce the patch > size significantly. And there will be no need for the unit selector > mechanism which I'm not sure will be accepted by the SCSI community. > So this would be modifying the existing sysfs entries so that reads still come from the device and unit descriptors, but writes go to equivalent fields in the config descriptor? I can explore that approach. Alternatively, if the unit selector mechanism is not desired, I could dynamically create sysfs directories for each unit in the config descriptor, but still bring out the config descriptor values as separate entries. (I still worry a bit about smashing the descriptors together as the UFS spec called them out as different). -Evan
