Hello,
On Tue, August 28, 2012 08:53, Jani Nikula wrote:
> From: Daniel Vetter <daniel.vetter at ffwll.ch>
>
> This is a prep patch to stop drm/i915 from changing the LBPC registers
> itself - but we still need to properly save/restore it on
> suspend/resume.
>
> Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> ---
> drivers/gpu/drm/i915/i915_drv.h | 1 +
> drivers/gpu/drm/i915/i915_reg.h | 3 +++
> drivers/gpu/drm/i915/i915_suspend.c | 8 ++++++++
> drivers/gpu/drm/i915/intel_panel.c | 2 --
> 4 files changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 58b43db..af1701c 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -606,6 +606,7 @@ typedef struct drm_i915_private {
> u32 savePP_CONTROL;
> u32 savePP_DIVISOR;
> u32 savePFIT_CONTROL;
> + u8 saveLBPC;
> u32 save_palette_a[256];
> u32 save_palette_b[256];
> u32 saveDPFC_CB_BASE;
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index d0b60f2..3303c18 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -1889,6 +1889,9 @@
>
> #define PFIT_AUTO_RATIOS 0x61238
>
> +/* legacy/combination backlight modes in pci config space. */
> +#define PCI_LBPC 0xf4
> +
> /* Backlight control */
> #define BLC_PWM_CTL2 0x61250 /* 965+ only */
> #define BLM_PWM_ENABLE (1 << 31)
> diff --git a/drivers/gpu/drm/i915/i915_suspend.c b/drivers/gpu/drm/i915/i915_suspend.c
> index 4776ccf..05daff7 100644
> --- a/drivers/gpu/drm/i915/i915_suspend.c
> +++ b/drivers/gpu/drm/i915/i915_suspend.c
> @@ -639,6 +639,10 @@ static void i915_save_display(struct drm_device *dev)
> dev_priv->saveBLC_PWM_CTL2 = I915_READ(BLC_PWM_CTL2);
> if (IS_MOBILE(dev) && !IS_I830(dev))
> dev_priv->saveLVDS = I915_READ(LVDS);
> +
> + if (IS_GEN2(dev) || IS_GEN4(dev))
> + pci_read_config_byte(dev->pdev, PCI_LBPC,
> + &dev_priv->saveLBPC);
What about GEN3?
It seems weird that LBPC wouldn't be restored during resume by some BIOSes,
is this really necessary?
Greetings,
Indan
