Re: [PATCH 2/8] drm/i915: remove LBB config save/restore

Jesse Barnes
2011-03-22T01:39:05Z

On Tue, 22 Mar 2011 09:29:14 +0800
Zhenyu Wang <zhenyuw@linux.intel.com> wrote:

> On 2011.03.21 10:36:01 -0700, Jesse Barnes wrote:
> > On Mon, 21 Mar 2011 17:27:13 +0800
> > Zhenyu Wang <zhenyuw@linux.intel.com> wrote:
> >
> > > we don't use it anywhere.
> > >
> > > Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
> > > ---
> > > drivers/gpu/drm/i915/i915_suspend.c | 4 ----
> > > 1 files changed, 0 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/i915/i915_suspend.c b/drivers/gpu/drm/i915/i915_suspend.c
> > > index 0521ecf..422981b 100644
> > > --- a/drivers/gpu/drm/i915/i915_suspend.c
> > > +++ b/drivers/gpu/drm/i915/i915_suspend.c
> > > @@ -795,8 +795,6 @@ int i915_save_state(struct drm_device *dev)
> > > struct drm_i915_private *dev_priv = dev->dev_private;
> > > int i;
> > >
> > > - pci_read_config_byte(dev->pdev, LBB, &dev_priv->saveLBB);
> > > -
> > > /* Hardware status page */
> > > dev_priv->saveHWS = I915_READ(HWS_PGA);
> > >
> > > @@ -844,8 +842,6 @@ int i915_restore_state(struct drm_device *dev)
> > > struct drm_i915_private *dev_priv = dev->dev_private;
> > > int i;
> > >
> > > - pci_write_config_byte(dev->pdev, LBB, dev_priv->saveLBB);
> > > -
> > > /* Hardware status page */
> > > I915_WRITE(HWS_PGA, dev_priv->saveHWS);
> >
> > This may affect older platforms and prevent backlight save/restore? At
> > least I think that's why we added it in the first place...
> >
>
> oh, I just grep it's not used any more, or we plan to add it back?

I thought we just re-introduced legacy mode so we modify the reg
again... Either way we may need to save/restore it even if the BIOS is
the one that whacks it when we call ACPI.

--
Jesse Barnes, Intel Open Source Technology Center