On Fri, Jul 19, 2013 at 03:02:01PM -0700, Kamal Mostafa wrote:
> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=47941
> BugLink: https://bugs.launchpad.net/bugs/1163720
> BugLink: https://bugs.launchpad.net/bugs/1162026
>
> Some machines suffer from non-functional backlight controls if
> BLM_PCH_PWM_ENABLE is set, so provide a quirk to avoid doing so.
> Apply this quirk to Dell XPS 13 models.
>
> Tested-by: Eric Griffith <egriffit...@gmail.com>
> Tested-by: Kent Baxley <kent.bax...@canonical.com>
> Cc: <sta...@vger.kernel.org> # v3.8+
> Signed-off-by: Kamal Mostafa <ka...@canonical.com>
I still wonder what exactly's going on here, but for backlight stuff I've
given up on avoiding quirks ;-) Thanks for digging into this, patch
applied to -fixes.
-Daniel
> ---
> drivers/gpu/drm/i915/i915_drv.h | 1 +
> drivers/gpu/drm/i915/intel_display.c | 16 ++++++++++++++++
> drivers/gpu/drm/i915/intel_panel.c | 3 ++-
> 3 files changed, 19 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index a416645..204c3ec 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -555,6 +555,7 @@ enum intel_sbi_destination {
> #define QUIRK_PIPEA_FORCE (1<<0)
> #define QUIRK_LVDS_SSC_DISABLE (1<<1)
> #define QUIRK_INVERT_BRIGHTNESS (1<<2)
> +#define QUIRK_NO_PCH_PWM_ENABLE (1<<3)
>
> struct intel_fbdev;
> struct intel_fbc_work;
> diff --git a/drivers/gpu/drm/i915/intel_display.c
> b/drivers/gpu/drm/i915/intel_display.c
> index 85f3eb7..42e207e 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -9398,6 +9398,17 @@ static void quirk_invert_brightness(struct drm_device
> *dev)
> DRM_INFO("applying inverted panel brightness quirk\n");
> }
>
> +/*
> + * Some machines (Dell XPS13) suffer broken backlight controls if
> + * BLM_PCH_PWM_ENABLE is set.
> + */
> +static void quirk_no_pcm_pwm_enable(struct drm_device *dev)
> +{
> + struct drm_i915_private *dev_priv = dev->dev_private;
> + dev_priv->quirks |= QUIRK_NO_PCH_PWM_ENABLE;
> + DRM_INFO("applying no-PCH_PWM_ENABLE quirk\n");
> +}
> +
> struct intel_quirk {
> int device;
> int subsystem_vendor;
> @@ -9467,6 +9478,11 @@ static struct intel_quirk intel_quirks[] = {
>
> /* Acer Aspire 4736Z */
> { 0x2a42, 0x1025, 0x0260, quirk_invert_brightness },
> +
> + /* Dell XPS13 HD Sandy Bridge */
> + { 0x0116, 0x1028, 0x052e, quirk_no_pcm_pwm_enable },
> + /* Dell XPS13 HD and XPS13 FHD Ivy Bridge */
> + { 0x0166, 0x1028, 0x058b, quirk_no_pcm_pwm_enable },
> };
>
> static void intel_init_quirks(struct drm_device *dev)
> diff --git a/drivers/gpu/drm/i915/intel_panel.c
> b/drivers/gpu/drm/i915/intel_panel.c
> index 80bea1d..01b5a51 100644
> --- a/drivers/gpu/drm/i915/intel_panel.c
> +++ b/drivers/gpu/drm/i915/intel_panel.c
> @@ -580,7 +580,8 @@ void intel_panel_enable_backlight(struct drm_device *dev,
> POSTING_READ(reg);
> I915_WRITE(reg, tmp | BLM_PWM_ENABLE);
>
> - if (HAS_PCH_SPLIT(dev)) {
> + if (HAS_PCH_SPLIT(dev) &&
> + !(dev_priv->quirks & QUIRK_NO_PCH_PWM_ENABLE)) {
> tmp = I915_READ(BLC_PWM_PCH_CTL1);
> tmp |= BLM_PCH_PWM_ENABLE;
> tmp &= ~BLM_PCH_OVERRIDE_ENABLE;
> --
> 1.8.1.2
>
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
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