3.4-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. [ kamal: backport to 3.4 ] 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_lvds.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 @@ -296,6 +296,7 @@ enum intel_pch { #define QUIRK_PIPEA_FORCE (1<<0) #define QUIRK_LVDS_SSC_DISABLE (1<<1) +#define QUIRK_NO_PCH_PWM_ENABLE (1<<2) struct intel_fbdev; struct intel_fbc_work; --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -9160,6 +9160,17 @@ static void quirk_ssc_force_disable(stru dev_priv->quirks |= QUIRK_LVDS_SSC_DISABLE; } +/* + * 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; @@ -9192,6 +9203,11 @@ struct intel_quirk intel_quirks[] = { /* Sony Vaio Y cannot use SSC on LVDS */ { 0x0046, 0x104d, 0x9076, quirk_ssc_force_disable }, + + /* 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_lvds.c +++ b/drivers/gpu/drm/i915/intel_lvds.c @@ -1097,7 +1097,8 @@ bool intel_lvds_init(struct drm_device * goto failed; out: - if (HAS_PCH_SPLIT(dev)) { + if (HAS_PCH_SPLIT(dev) && + !(dev_priv->quirks & QUIRK_NO_PCH_PWM_ENABLE)) { u32 pwm; pipe = (I915_READ(PCH_LVDS) & LVDS_PIPEB_SELECT) ? 1 : 0; -- 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