3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kamal Mostafa <kamal@xxxxxxxxxxxxx> commit e85843bec6c2ea7c10ec61238396891cc2b753a9 upstream. 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 <EGriffith92@xxxxxxxxx> Tested-by: Kent Baxley <kent.baxley@xxxxxxxxxxxxx> Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx> Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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(-) --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -491,6 +491,7 @@ 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; --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -8917,6 +8917,17 @@ static void quirk_invert_brightness(stru 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; @@ -8986,6 +8997,11 @@ 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) --- a/drivers/gpu/drm/i915/intel_panel.c +++ b/drivers/gpu/drm/i915/intel_panel.c @@ -354,7 +354,8 @@ void intel_panel_enable_backlight(struct 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; -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html