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>
This commit is contained in:
Sonika Jindal 2015-05-06 17:35:48 +05:30 committed by Daniel Vetter
parent 983b4b9def
commit 9e45803465
5 changed files with 20 additions and 5 deletions

View file

@ -1364,7 +1364,6 @@ struct intel_vbt_data {
bool edp_initialized;
bool edp_support;
int edp_bpp;
bool edp_low_vswing;
struct edp_power_seq edp_pps;
struct {
@ -1846,6 +1845,8 @@ struct drm_i915_private {
void (*stop_ring)(struct intel_engine_cs *ring);
} gt;
bool edp_low_vswing;
/*
* NOTE: This is the dri1/ums dungeon, don't add stuff here. Your patch
* will be rejected. Instead look for a better place.
@ -2515,6 +2516,7 @@ struct i915_params {
int mmio_debug;
bool verbose_state_checks;
bool nuclear_pageflip;
int edp_vswing;
};
extern struct i915_params i915 __read_mostly;

View file

@ -53,6 +53,7 @@ struct i915_params i915 __read_mostly = {
.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_PARM_DESC(verbose_state_checks,
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))");

View file

@ -672,8 +672,13 @@ parse_edp(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
if (bdb->version >= 173) {
uint8_t vswing;
vswing = (edp->edp_vswing_preemph >> (panel_type * 4)) & 0xF;
dev_priv->vbt.edp_low_vswing = vswing == 0;
/* Don't read from VBT if module parameter has valid value*/
if (i915.edp_vswing) {
dev_priv->edp_low_vswing = i915.edp_vswing == 1;
} else {
vswing = (edp->edp_vswing_preemph >> (panel_type * 4)) & 0xF;
dev_priv->edp_low_vswing = vswing == 0;
}
}
}

View file

@ -282,7 +282,7 @@ static void intel_prepare_ddi_buffers(struct drm_device *dev, enum port port,
ddi_translations_fdi = NULL;
ddi_translations_dp = skl_ddi_translations_dp;
n_dp_entries = ARRAY_SIZE(skl_ddi_translations_dp);
if (dev_priv->vbt.edp_low_vswing) {
if (dev_priv->edp_low_vswing) {
ddi_translations_edp = skl_ddi_translations_edp;
n_edp_entries = ARRAY_SIZE(skl_ddi_translations_edp);
} else {

View file

@ -2894,7 +2894,7 @@ intel_dp_voltage_max(struct intel_dp *intel_dp)
if (IS_BROXTON(dev))
return DP_TRAIN_VOLTAGE_SWING_LEVEL_3;
else if (INTEL_INFO(dev)->gen >= 9) {
if (dev_priv->vbt.edp_low_vswing && port == PORT_A)
if (dev_priv->edp_low_vswing && port == PORT_A)
return DP_TRAIN_VOLTAGE_SWING_LEVEL_3;
return DP_TRAIN_VOLTAGE_SWING_LEVEL_2;
} else if (IS_VALLEYVIEW(dev))