drm/i915/skl: Add module parameter to select edp vswing table
This provides an option to override the value set by VBT
for selecting edp Vswing Pre-emph setting table.
v2: Adding comment about this being a temporary workaround and
making the parameter read-only (Jani)
v3: Changing mode to 0400 instead of 0 (Jani)
https://bugs.freedesktop.org/show_bug.cgi?id=89554
Signed-off-by: Sonika Jindal <sonika.jindal@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
index bb64415..8ac5a1b 100644
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -53,6 +53,7 @@
.mmio_debug = 0,
.verbose_state_checks = 1,
.nuclear_pageflip = 0,
+ .edp_vswing = 0,
};
module_param_named(modeset, i915.modeset, int, 0400);
@@ -184,3 +185,10 @@
module_param_named_unsafe(nuclear_pageflip, i915.nuclear_pageflip, bool, 0600);
MODULE_PARM_DESC(nuclear_pageflip,
"Force atomic modeset functionality; only planes work for now (default: false).");
+
+/* WA to get away with the default setting in VBT for early platforms.Will be removed */
+module_param_named_unsafe(edp_vswing, i915.edp_vswing, int, 0400);
+MODULE_PARM_DESC(edp_vswing,
+ "Ignore/Override vswing pre-emph table selection from VBT "
+ "(0=use value from vbt [default], 1=low power swing(200mV),"
+ "2=default swing(400mV))");