In full-AUX VESA mode (aux_enable && aux_set) the driver never touches
the native PCH PWM. If BIOS left PWM CTL register enabled, the PCH PWM
keeps system alive during s2idle and blocks S0ix.
Always run pwm_funcs->setup() so pwm_enabled reflects real HW state,
and on first enable in full-AUX mode call pwm_funcs->disable() once to
clear the stale bit. Runtime behaviour is otherwise unchanged.
Fixes: 40d2f5820951 ("drm/i915/backlight: Remove try_vesa_interface")
Signed-off-by: Suraj Kandpal <[email protected]>
---
.../drm/i915/display/intel_dp_aux_backlight.c | 32 +++++++++++++------
1 file changed, 23 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
index a8d56ebf06a2..c828c568fb8b 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
@@ -496,6 +496,17 @@ intel_dp_aux_vesa_enable_backlight(const struct
intel_crtc_state *crtc_state,
struct intel_panel *panel = &connector->panel;
struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
+ /*
+ * In full AUX VESA mode the native PWM is never driven by us. If BIOS
+ * left it enabled, the PCH PWM keeps the system alive and blocks
+ * S0ix. Sanitize it once via pwm_funcs->disable.
+ */
+ if (panel->backlight.edp.vesa.info.aux_enable &&
+ panel->backlight.edp.vesa.info.aux_set &&
+ panel->backlight.pwm_enabled)
+ panel->backlight.pwm_funcs->disable(conn_state,
+
intel_backlight_invert_pwm_level(connector, 0));
+
if (!(panel->backlight.edp.vesa.info.aux_enable ||
panel->backlight.edp.vesa.info.luminance_set)) {
u32 pwm_level;
@@ -558,15 +569,18 @@ static int intel_dp_aux_vesa_setup_backlight(struct
intel_connector *connector,
panel->backlight.edp.vesa.info.luminance_set),
backlight_unit_str(panel));
- if (!panel->backlight.edp.vesa.info.aux_set ||
- !panel->backlight.edp.vesa.info.aux_enable) {
- ret = panel->backlight.pwm_funcs->setup(connector, pipe);
- if (ret < 0) {
- drm_err(display->drm,
- "[CONNECTOR:%d:%s] Failed to setup PWM
backlight controls for eDP backlight: %d\n",
- connector->base.base.id, connector->base.name,
ret);
- return ret;
- }
+ /*
+ * Always probe the native PWM HW state so panel->backlight.pwm_enabled
+ * reflects what BIOS left behind. Required for the full-AUX VESA path
+ * to detect and sanitize a BIOS-enabled PCH PWM that would otherwise
+ * block S0ix.
+ */
+ ret = panel->backlight.pwm_funcs->setup(connector, pipe);
+ if (ret < 0) {
+ drm_err(display->drm,
+ "[CONNECTOR:%d:%s] Failed to setup PWM backlight
controls for eDP backlight: %d\n",
+ connector->base.base.id, connector->base.name, ret);
+ return ret;
}
if (panel->backlight.edp.vesa.info.luminance_set) {
--
2.34.1
