Re: [Intel-xe] [PATCH V2] drm/xe: make GT sysfs init return void

[Nirmoy Das <nirmoy.das@linux.intel.com>]

Hi Ashutosh,

On 7/5/2023 5:47 PM, Dixit, Ashutosh wrote:
> On Wed, 05 Jul 2023 08:39:20 -0700, Nirmoy Das wrote:
>> Hi Ashutosh,
>>
>> On 7/5/2023 4:06 PM, Dixit, Ashutosh wrote:
>>> On Wed, 05 Jul 2023 01:44:03 -0700, Tejas Upadhyay wrote:
>>>> Currently return from xe_gt_sysfs_init() is ignored
>>>> and also a failure in xe_gt_sysfs_init() isn't fatal
>>>> so make it return void.
>>> But why is the failure not fatal? I really don't understand the concept of
>>> these non-fatal failures. Do we really want to say the device is up if
>>> sysfs initialization has failed for some reason and people are unable to
>>> see card freq's e.g.? This was done in i915 but do we really want to repeat
>>> this for xe? IMO the simplest thing to do would be to fail the probe unless
>>> ALL required/intended functionality is clearly up.
>>
>> I agree with the concern but the situation is different with a graphics
>> driver.
>>
>> If we return error on probe, (if I am not wrong) a user will have no way to
>> interact
>>
>> with the system other than ssh. We should ignore non-fatal error and let
>> the driver load
>>
>> so a user can have something to work with(may be report a bug :) )
> Hmm, good point. Agreed :)
>
> This way though only display is critical and everything else non-critical?

Yes, that would be wrong, I am not saying that. We do return error 
during the probe at multiple locations,

I believe we can prioritize system usability by considering this 
specific error as non-critical. Although those sysfs files are important,

the device should still usable without them.


Thanks,

Nirmoy

> My point was knowing (or controlling) GPU freq's is a pretty important part
> of doing work on the GPU.
>
> In any case, since we are printing an error in dmesg if sysfs init fails,
> maybe converting to void is ok. So this is:
>
> Acked-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
>
>>
>> Regards,
>>
>> Nirmoy
>>
>>> Instead of ignoring the return, fail the probe?
>>>
>>> Thanks.
>>> --
>>> Ashutosh