@@ -61,7 +61,7 @@ struct i915_params i915 __read_mostly = {
.guc_log_level = -1,
.enable_dp_mst = true,
.inject_load_failure = 0,
- .enable_dpcd_backlight = false,
+ .enable_dpcd_backlight = 0,
.enable_gvt = false,
};
@@ -236,9 +236,9 @@ MODULE_PARM_DESC(enable_dp_mst,
module_param_named_unsafe(inject_load_failure, i915.inject_load_failure, uint, 0400);
MODULE_PARM_DESC(inject_load_failure,
"Force an error after a number of failure check points (0:disabled (default), N:force failure at the Nth failure check point)");
-module_param_named(enable_dpcd_backlight, i915.enable_dpcd_backlight, bool, 0600);
+module_param_named(enable_dpcd_backlight, i915.enable_dpcd_backlight, int, 0600);
MODULE_PARM_DESC(enable_dpcd_backlight,
- "Enable support for DPCD backlight control (default:false)");
+ "Enable support for DPCD backlight control (0:disable (default), 1:prefer PWM pin, 2: prefer DPCD)");
module_param_named(enable_gvt, i915.enable_gvt, bool, 0400);
MODULE_PARM_DESC(enable_gvt,
@@ -49,6 +49,7 @@
func(int, use_mmio_flip); \
func(int, mmio_debug); \
func(int, edp_vswing); \
+ func(int, enable_dpcd_backlight); \
func(unsigned int, inject_load_failure); \
/* leave bools at the end to not create holes */ \
func(bool, alpha_support); \
@@ -64,7 +65,6 @@
func(bool, verbose_state_checks); \
func(bool, nuclear_pageflip); \
func(bool, enable_dp_mst); \
- func(bool, enable_dpcd_backlight); \
func(bool, enable_gvt)
#define MEMBER(T, member) T member
@@ -28,6 +28,10 @@ static void set_aux_backlight_enable(struct intel_dp *intel_dp, bool enable)
{
uint8_t reg_val = 0;
+ /* Early return when display use other mechanism to enable backlight. */
+ if (!(intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP))
+ return;
+
if (drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_DISPLAY_CONTROL_REGISTER,
®_val) < 0) {
DRM_DEBUG_KMS("Failed to read DPCD register 0x%x\n",
@@ -138,27 +142,36 @@ static bool
intel_dp_aux_display_control_capable(struct intel_connector *connector)
{
struct intel_dp *intel_dp = enc_to_intel_dp(&connector->encoder->base);
+ bool supported;
/* Check the eDP Display control capabilities registers to determine if
* the panel can support backlight control over the aux channel
*/
- if (intel_dp->edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP &&
- (intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP) &&
- !((intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_PIN_ENABLE_CAP) ||
- (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP))) {
- DRM_DEBUG_KMS("AUX Backlight Control Supported!\n");
- return true;
+ switch (i915.enable_dpcd_backlight) {
+ case 1: /* prefer PWM pin */
+ supported = (intel_dp->edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP) &&
+ (intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP) &&
+ !(intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_PIN_ENABLE_CAP) &&
+ !(intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP);
+ break;
+ case 2: /* prefer DPCD */
+ supported = (intel_dp->edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP) &&
+ (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP);
+ break;
+ default:
+ supported = false;
}
- return false;
+
+ if (supported)
+ DRM_DEBUG_KMS("AUX Backlight Control Supported!\n");
+
+ return supported;
}
int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector)
{
struct intel_panel *panel = &intel_connector->panel;
- if (!i915.enable_dpcd_backlight)
- return -ENODEV;
-
if (!intel_dp_aux_display_control_capable(intel_connector))
return -ENODEV;
Currently the intel_dp_aux_backlight driver requires eDP panel to not also support backlight adjustment via PWM pin to use this driver. This force the eDP panel that support both ways of backlight adjustment to do it via PWM pin. This patch adds the new prefer DPCD mode in the i915_param to make it enable to prefer DPCD over the PWM via kernel param. This patch also add a check to DP_EDP_BACKLIGHT_AUX_ENABLE_CAP in set_aux_backlight_enable() since the backlight enablement can be done via BL_ENABLE eDP connector pin in the case that it does not support doing that via AUX. Signed-off-by: Puthikorn Voravootivat <puthik@chromium.org> --- drivers/gpu/drm/i915/i915_params.c | 6 ++--- drivers/gpu/drm/i915/i915_params.h | 2 +- drivers/gpu/drm/i915/intel_dp_aux_backlight.c | 33 +++++++++++++++++++-------- 3 files changed, 27 insertions(+), 14 deletions(-)