drm/i915: Allow SSC parameter to override VBT value
Allow SSC to be enabled even when the BIOS disables it for testing SSC paths.
Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index f07e425..58480de 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -79,11 +79,11 @@
"Use panel (LVDS/eDP) downclocking for power savings "
"(default: false)");
-unsigned int i915_panel_use_ssc __read_mostly = 1;
+unsigned int i915_panel_use_ssc __read_mostly = -1;
module_param_named(lvds_use_ssc, i915_panel_use_ssc, int, 0600);
MODULE_PARM_DESC(lvds_use_ssc,
"Use Spread Spectrum Clock with panels [LVDS/eDP] "
- "(default: true)");
+ "(default: auto from VBT)");
int i915_vbt_sdvo_panel_type __read_mostly = -1;
module_param_named(vbt_sdvo_panel_type, i915_vbt_sdvo_panel_type, int, 0600);
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 04411ad..6039496 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4584,7 +4584,9 @@
static inline bool intel_panel_use_ssc(struct drm_i915_private *dev_priv)
{
- return dev_priv->lvds_use_ssc && i915_panel_use_ssc
+ if (i915_panel_use_ssc >= 0)
+ return i915_panel_use_ssc != 0;
+ return dev_priv->lvds_use_ssc
&& !(dev_priv->quirks & QUIRK_LVDS_SSC_DISABLE);
}