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drm/i915: Add quirk to disable SSC on Lenovo U160 LVDS

PATCH In review Keith Packard 2 participants 2 messages Jul 13, 2011

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DRM drivers Intel i915
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Keith Packard

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PATCH 1/1 drm/i915: Add quirk to disable SSC on Lenovo U160 LVDS

We've tried several times to make this machine 'just work', but every patch that does causes many other machines to fail. This adds a quirk which special cases this hardware and forces ssc to be disabled. There's no way to override this from the command line; that would be a significantly more invasive change.

Signed-off-by Keith Packard <[email protected]>
Tested-by Robse <[email protected]>
---
 drivers/gpu/drm/i915/i915_drv.h      |    1 +
 drivers/gpu/drm/i915/intel_display.c |   15 ++++++++++++++-
 2 files changed, 15 insertions(+), 1 deletions(-)
drivers/gpu/drm/i915/i915_drv.h +1 -0
index f245c58..6042921 100644
@@ -262,6 +262,7 @@ enum intel_pch {
 };
 
 #define QUIRK_PIPEA_FORCE (1<<0)
+#define QUIRK_LVDS_SSC_DISABLE (1<<1)
 
 struct intel_fbdev;
drivers/gpu/drm/i915/intel_display.c +14 -1
index 21b6f93..252c6f0 100644
@@ -4305,7 +4305,8 @@ static void intel_update_watermarks(struct drm_device *dev)
 
 static inline bool intel_panel_use_ssc(struct drm_i915_private *dev_priv)
 {
-	return dev_priv->lvds_use_ssc && i915_panel_use_ssc;
+	return dev_priv->lvds_use_ssc && i915_panel_use_ssc
+		&& !(dev_priv->quirks & QUIRK_LVDS_SSC_DISABLE);
 }
 
 static int i9xx_crtc_mode_set(struct drm_crtc *crtc,

@@ -7810,6 +7811,15 @@ static void quirk_pipea_force (struct drm_device *dev)
 	DRM_DEBUG_DRIVER("applying pipe a force quirk\n");
 }
 
+/*
+ * Some machines (Lenovo U160) do not work with SSC on LVDS for some reason
+ */
+static void quirk_ssc_force_disable (struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	dev_priv->quirks |= QUIRK_LVDS_SSC_DISABLE;
+}
+
 struct intel_quirk {
 	int device;
 	int subsystem_vendor;

@@ -7838,6 +7848,9 @@ struct intel_quirk intel_quirks[] = {
 	/* 855 & before need to leave pipe A & dpll A up */
 	{ 0x3582, PCI_ANY_ID, PCI_ANY_ID, quirk_pipea_force },
 	{ 0x2562, PCI_ANY_ID, PCI_ANY_ID, quirk_pipea_force },
+
+	/* Lenovo U160 cannot use SSC on LVDS */
+	{ 0x0046, 0x17aa, 0x3920, quirk_ssc_force_disable },
 };
 
 static void intel_init_quirks(struct drm_device *dev)
Signature · 6 lines
1.7.5.4



-- 
[email protected]
Reviewed-by on v1 1/1
#1 lore raw

On Wed, 13 Jul 2011 13:09:28 -0700, "Keith Packard" <[email protected]> wrote:
Non-text part: multipart/signed

Quoted 9 lines

We've tried several times to make this machine 'just work', but every patch that does causes many other machines to fail. This adds a quirk which special cases this hardware and forces ssc to be disabled. There's no way to override this from the command line; that would be a significantly more invasive change.

Signed-off-by Keith Packard <[email protected]>
Tested-by Robse <[email protected]>

References: https://bugs.freedesktop.org/show_bug.cgi?id=36656

Reviewed-by Chris Wilson <[email protected]>
Signature · 1 line
Chris Wilson, Intel Open Source Technology Centre