On Thu, Sep 26, 2024 at 10:43:21AM -0400, Rodrigo Vivi wrote:
> On Wed, Sep 25, 2024 at 05:45:22PM +0300, Ville Syrjala wrote:
> > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> >
> > driver/pci does the pci_save_state()+pci_set_power_state() from the
> > _noirq() pm hooks. Move our manual calls (needed for the hibernate+D3
> > workaround with buggy BIOSes) towards that same point. We currently
> > have no _noirq() hooks, so end of _late() hooks is the best we can
> > do right now.
> >
> > Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> > Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
> > Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
> > Cc: linux-pci@xxxxxxxxxxxxxxx
> > Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> > ---
> > drivers/gpu/drm/i915/i915_driver.c | 19 ++++++++++++++-----
> > 1 file changed, 14 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c
> > index 6dc0104a3e36..9d557ff8adf5 100644
> > --- a/drivers/gpu/drm/i915/i915_driver.c
> > +++ b/drivers/gpu/drm/i915/i915_driver.c
> > @@ -1015,7 +1015,6 @@ static int i915_drm_suspend(struct drm_device *dev)
> > {
> > struct drm_i915_private *dev_priv = to_i915(dev);
> > struct intel_display *display = &dev_priv->display;
> > - struct pci_dev *pdev = to_pci_dev(dev_priv->drm.dev);
> > pci_power_t opregion_target_state;
> >
> > disable_rpm_wakeref_asserts(&dev_priv->runtime_pm);
> > @@ -1029,8 +1028,6 @@ static int i915_drm_suspend(struct drm_device *dev)
> > intel_display_driver_disable_user_access(dev_priv);
> > }
> >
> > - pci_save_state(pdev);
> > -
> > intel_display_driver_suspend(dev_priv);
> >
> > intel_dp_mst_suspend(dev_priv);
> > @@ -1090,10 +1087,16 @@ static int i915_drm_suspend_late(struct drm_device *dev, bool hibernation)
> > drm_err(&dev_priv->drm, "Suspend complete failed: %d\n", ret);
> > intel_power_domains_resume(dev_priv);
> >
> > - goto out;
> > + goto fail;
> > }
> >
> > + enable_rpm_wakeref_asserts(rpm);
> > +
> > + if (!dev_priv->uncore.user_forcewake_count)
> > + intel_runtime_pm_driver_release(rpm);
> > +
>
> why do we need this?
> probably deserves a separate patch?
It was there already.
>
> > pci_disable_device(pdev);
> > +
> > /*
> > * During hibernation on some platforms the BIOS may try to access
> > * the device even though it's already in D3 and hang the machine. So
> > @@ -1105,11 +1108,17 @@ static int i915_drm_suspend_late(struct drm_device *dev, bool hibernation)
> > * Lenovo Thinkpad X301, X61s, X60, T60, X41
> > * Fujitsu FSC S7110
> > * Acer Aspire 1830T
> > + *
> > + * pci_save_state() is needed to prevent driver/pci from
> > + * automagically putting the device into D3.
> > */
>
> I'm still not convinced that this would automagically prevent the D3,
> specially in this part of the code.
You need to read pci_pm_poweroff_noirq()
>
> I would prefer to simply remove this call, or keep it and move it
> here to be consistent with other drivers, but also add the restore
> portion of it for consistency and alignment...
>
> > + pci_save_state(pdev);
> > if (!(hibernation && GRAPHICS_VER(dev_priv) < 6))
> > pci_set_power_state(pdev, PCI_D3hot);
> >
> > -out:
> > + return 0;
> > +
> > +fail:
> > enable_rpm_wakeref_asserts(rpm);
> > if (!dev_priv->uncore.user_forcewake_count)
> > intel_runtime_pm_driver_release(rpm);
> > --
> > 2.44.2
> >
--
Ville Syrjälä
Intel
