Re: [PATCH 5/6] drm/i915/pm: Do pci_restore_state() in switcheroo resume hook

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Wed, Sep 25, 2024 at 05:45:25PM +0300, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> 
> Since this switcheroo stuff bypasses all the core pm we
> have to manually manage the pci state. To that end add the
> missing pci_restore_state() to the switcheroo resume hook.
> We already have the pci_save_state() counterpart on the
> suspend side.
> 
> I suppose this might not matter in practice as the
> integrated GPU probably won't lose any state in D3,
> and I presume there are no machines where this code
> would come into play with an Intel discrete GPU.
> 
> Arguably none of this code should exist in the driver
> in the first place, and instead the entire switcheroo
> mechanism should be rewritten and properly integrated into
> core pm code...
> 
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Cc: linux-pci@vger.kernel.org
> Cc: intel-gfx@lists.freedesktop.org
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/i915_driver.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c
> index fe7c34045794..c3e7225ea1ba 100644
> --- a/drivers/gpu/drm/i915/i915_driver.c
> +++ b/drivers/gpu/drm/i915/i915_driver.c
> @@ -1311,6 +1311,8 @@ int i915_driver_resume_switcheroo(struct drm_i915_private *i915)
>  	if (ret)
>  		return ret;
>  
> +	pci_restore_state(pdev);

then why not simply call that inside the resume, for a better alignment
with the save counterpart?

> +
>  	ret = i915_drm_resume_early(&i915->drm);
>  	if (ret)
>  		return ret;
> -- 
> 2.44.2
>