[ 15/25] drm/i915: quirk no PCH_PWM_ENABLE for Dell XPS13 backlight

Greg Kroah-Hartman
2013-08-09T01:53:45Z

From: Kamal Mostafa <kamal@canonical.com>

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@gmail.com>
Tested-by: Kent Baxley <kent.baxley@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
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;