Re: [PATCH 1/1] ishtp: Add support for Intel ishtp eclite driver

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 6/3/21 6:48 PM, K Naduvalath, Sumesh wrote:
> Thank you Hans for the scrutiny. Please find my comments inline.

<snip>

>>> ISH Firmware (the PSE subsystem) can boot up/reinitialize Every Sx
>>> based on usecase or sometimes PSE is always-on. So the resume path is
>>> asynchronous and unpredictable in this case. Re-initialization and
>>> clean up required if PSE also boot up every Sx and might take good
>>> amount of time (Host can come alive before PSE comes up). Thus using
>> asynchronous reset notification.
>>
>> Ok, so I guess we need to live with the ugly deregister + re-register OpRegion
>> dance for the devices where the PSE is shutdown during suspend.
>>
>> You also write: "sometimes PSE is always-on", what about that case, I assume
>> in this case there will be no reset after resume? So then unregistering the
>> OpRegion handler at suspend (and setting link_ready=false) will be wrong
>> since without the reset the OpRegion handler will never get reinstalled ?
> 
> reset is called from bus after every resume. When PSE is always-on, the notification
> comes quicky, where as there reset comes bit later in case of new boot.

Ok, in that case it makes sense to treat the PSE always-on scenario the same
as the scenario where it gets turned off during suspend.

Regards,

Hans