Re: [PATCH v2] scsi: ufs: critical health condition

[Bart Van Assche]

On 2/6/25 9:47 AM, Avri Altman wrote:
> > On 2/6/25 12:54 AM, Avri Altman wrote:
> > > After some further internal discussions: The set conditions are vendor
> > > specific; The device may set it as many times it wants depending on
> > > its criticality. The spec does not define that nor what the host
> > > should do. So there is this concern that some vendors will report
> > > multiple times, while other wont. Hence, reading critical_health = 1
> > > might be misleading. What do you think?
>
> Still not sure if you want this to be a counter?

Since the event can be reported multiple times, a counter sounds better
to me than a boolean.
> > How about emitting a uevent if a critical health condition has been reported by a
> > UFS device? See also sdev_evt_send().
> Thanks for pointing this out.
> A ufs event in enum scsi_device_event seems misplaced - looks like it was invented for unit attention codes.
> How about calling kobject_uevent() or  kobject_uevent_env() directly from the driver?

Please note that emitting a uevent is not the only possible approach for
informing user space code. Emitting a uevent is recommended if the code
that processes an event can be implemented as a shell script. Could it
be more likely that critical health events will be processed by C or C++
code rather than a shell script? If so, how about making the sysfs
attribute that reports the number of critical health events pollable? In
C and C++ code, polling a sysfs attribute requires less code than
listening for uevents.

Thanks,

Bart.