[PATCH] drm/i915: quirk no PCH_PWM_ENABLE for Dell XPS13 backlight
From: Kamal Mostafa
Date: Fri Jul 19 2013 - 18:02:14 EST
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>
Cc: <stable@xxxxxxxxxxxxxxx> # v3.8+
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
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
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