Re: [Intel-gfx] [PATCH] drm/i915/dgfx: Temporary hammer to keep autosuspend control 'on'

[Gupta, Anshuman]

> -----Original Message-----
> From: Dixit, Ashutosh <ashutosh.di...@intel.com>
> Sent: Wednesday, October 12, 2022 8:49 PM
> To: Auld, Matthew <matthew.a...@intel.com>
> Cc: Gupta, Anshuman <anshuman.gu...@intel.com>; intel-
> g...@lists.freedesktop.org; Vivi, Rodrigo <rodrigo.v...@intel.com>
> Subject: Re: [Intel-gfx] [PATCH] drm/i915/dgfx: Temporary hammer to keep
> autosuspend control 'on'
> 
> On Wed, 12 Oct 2022 02:48:30 -0700, Matthew Auld wrote:
> >
> > So with this change all the runtime pm stuff is disabled on dgfx? i.e
> > intel_runtime_pm_get() always returns zero or so?
> 
> I guess it should always return non-zero (or the wakeref) since the device is
> always on...
This patch does not disable runtime PM completely, it just disables autosuspend 
i.e by grabbing the  wakeref(device usage_count) at PM core level.  
intel_runtime_pm_get() is orthogonal to it and will get a wakeref and will 
increment the PM core device usage_count.
This just changes default behavior of i915, our igt rpm tests still overrides 
the autosuspend control to 'auto'.
I915 driver still vulnerable to any lmem access without a valid wakeref with 
our CI execution.  

Thanks,
Anshuman Gupta.