Messages in this thread | | | From | Evan Green <> | Date | Mon, 4 Jun 2018 07:59:14 -0700 | Subject | Re: [PATCH 0/7] Enable UFS provisioning via Linux |
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On Sun, Jun 3, 2018 at 3:21 AM Stanislav Nijnikov <Stanislav.Nijnikov@wdc.com> wrote: > > > > > -----Original Message----- > > From: linux-scsi-owner@vger.kernel.org <linux-scsi-owner@vger.kernel.org> On Behalf Of Evan Green > > Sent: Friday, June 1, 2018 5:44 PM > > To: Stanislav Nijnikov <Stanislav.Nijnikov@wdc.com> > > Cc: Vinayak Holikatti <vinholikatti@gmail.com>; jejb@linux.vnet.ibm.com; martin.petersen@oracle.com; linux- > > kernel@vger.kernel.org; linux-scsi@vger.kernel.org; Gwendal Grignou <gwendal@chromium.org>; Alex Lemberg > > <Alex.Lemberg@wdc.com>; Avri Altman <Avri.Altman@wdc.com> > > 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@wdc.com> 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
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