On Tue, 17 Jun 2025, Jani Nikula <jani.nik...@linux.intel.com> wrote:
> On Tue, 17 Jun 2025, Arun R Murthy <arun.r.mur...@intel.com> wrote:
>> Allocate and register drm_panel to allow the panel_follower framework to
>> detect the eDP panel and pass drm_connector::kdev device to drm_panel
>> allocation for matching.
>> Call drm_panel_prepare/unprepare in ddi_enable for eDP to allow the
>> followers to get notified of the panel power state changes.
>>
>> Signed-off-by: Arun R Murthy <arun.r.mur...@intel.com>
>> ---
>> v1: Initial patch version based on the panel_follower added for DSI by
>> Jani.
>> ---
>> drivers/gpu/drm/i915/display/intel_backlight.h | 1 +
>> drivers/gpu/drm/i915/display/intel_ddi.c | 4 ++++
>> drivers/gpu/drm/i915/display/intel_dp.c | 6 +++---
>> drivers/gpu/drm/i915/display/intel_dp.h | 1 +
>> drivers/gpu/drm/i915/display/intel_panel.c | 20 ++++++++++++++++----
>> 5 files changed, 25 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_backlight.h
>> b/drivers/gpu/drm/i915/display/intel_backlight.h
>> index
>> 339643f6389789a9b52c4c1d74e03d8f15a6efa6..ebeb6448188f0b8cf45edd1093439bd6b6e63111
>> 100644
>> --- a/drivers/gpu/drm/i915/display/intel_backlight.h
>> +++ b/drivers/gpu/drm/i915/display/intel_backlight.h
>> @@ -18,6 +18,7 @@ enum pipe;
>>
>> void intel_backlight_init_funcs(struct intel_panel *panel);
>> int intel_backlight_setup(struct intel_connector *connector, enum pipe
>> pipe);
>> +void intel_edp_backlight_setup(struct intel_connector *connector);
>> void intel_backlight_destroy(struct intel_panel *panel);
>>
>> void intel_backlight_enable(const struct intel_crtc_state *crtc_state,
>> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c
>> b/drivers/gpu/drm/i915/display/intel_ddi.c
>> index
>> cbd1060e966431e0884aa9df7b5e6d2f27fde6d5..36aa6d14589d37614fe13ba15baf4c7e60014e2c
>> 100644
>> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
>> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
>> @@ -73,6 +73,7 @@
>> #include "intel_lspcon.h"
>> #include "intel_mg_phy_regs.h"
>> #include "intel_modeset_lock.h"
>> +#include "intel_panel.h"
>> #include "intel_pfit.h"
>> #include "intel_pps.h"
>> #include "intel_psr.h"
>> @@ -3355,6 +3356,8 @@ static void intel_ddi_enable_dp(struct
>> intel_atomic_state *state,
>> drm_connector_update_privacy_screen(conn_state);
>> intel_edp_backlight_on(crtc_state, conn_state);
>>
>> + intel_panel_prepare(crtc_state, conn_state);
>> +
>> if (!intel_lspcon_active(dig_port) ||
>> intel_dp_has_hdmi_sink(&dig_port->dp))
>> intel_dp_set_infoframes(encoder, true, crtc_state, conn_state);
>>
>> @@ -3552,6 +3555,7 @@ static void intel_ddi_disable_dp(struct
>> intel_atomic_state *state,
>>
>> intel_dp->link.active = false;
>>
>> + intel_panel_unprepare(old_conn_state);
>> intel_psr_disable(intel_dp, old_crtc_state);
>> intel_alpm_disable(intel_dp);
>> intel_edp_backlight_off(old_conn_state);
>> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
>> b/drivers/gpu/drm/i915/display/intel_dp.c
>> index
>> 277b40b13948ed964f20aa1243f76aa263615360..451b6be6106d6ac244d23fe2d997b4f7b3e9f002
>> 100644
>> --- a/drivers/gpu/drm/i915/display/intel_dp.c
>> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
>> @@ -6464,9 +6464,9 @@ intel_edp_add_properties(struct intel_dp *intel_dp)
>> fixed_mode->vdisplay);
>> }
>>
>> -static void intel_edp_backlight_setup(struct intel_dp *intel_dp,
>> - struct intel_connector *connector)
>> +void intel_edp_backlight_setup(struct intel_connector *connector)
>
> Why?
>
>> {
>> + struct intel_dp *intel_dp = intel_attached_dp(connector);
>> struct intel_display *display = to_intel_display(intel_dp);
>> enum pipe pipe = INVALID_PIPE;
>>
>> @@ -6627,7 +6627,7 @@ static bool intel_edp_init_connector(struct intel_dp
>> *intel_dp,
>>
>> intel_panel_init(connector, drm_edid);
>>
>> - intel_edp_backlight_setup(intel_dp, connector);
>> + intel_panel_register(connector);
>
> First, this is *way* too early to register the panel. Second, now it's
> being done twice, and you'll have errors at probe.
Well, it's so early that connector->kdev hasn't been initialized yet, so
it bails out at probe.
>
> This change is not needed.
>
>>
>> intel_edp_add_properties(intel_dp);
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_dp.h
>> b/drivers/gpu/drm/i915/display/intel_dp.h
>> index
>> 0657f568119662828344cfddbe876f2acf2596d9..2544783d3d5ad0d8e334fbe3a9ab874e7fee559e
>> 100644
>> --- a/drivers/gpu/drm/i915/display/intel_dp.h
>> +++ b/drivers/gpu/drm/i915/display/intel_dp.h
>> @@ -214,5 +214,6 @@ int intel_dp_compute_min_hblank(struct intel_crtc_state
>> *crtc_state,
>>
>> int intel_dp_dsc_bpp_step_x16(const struct intel_connector *connector);
>> void intel_dp_dpcd_set_probe(struct intel_dp *intel_dp, bool
>> force_on_external);
>> +void intel_edp_backlight_setup(struct intel_connector *connector);
>>
>> #endif /* __INTEL_DP_H__ */
>> diff --git a/drivers/gpu/drm/i915/display/intel_panel.c
>> b/drivers/gpu/drm/i915/display/intel_panel.c
>> index
>> f956919dc648eab507cdcca149672c1ce0173481..e884d9de3666b17197e3003af7bd9388b2889e6f
>> 100644
>> --- a/drivers/gpu/drm/i915/display/intel_panel.c
>> +++ b/drivers/gpu/drm/i915/display/intel_panel.c
>> @@ -511,11 +511,21 @@ int intel_panel_register(struct intel_connector
>> *connector)
>> struct intel_panel *panel = &connector->panel;
>> int ret;
>>
>> - ret = intel_backlight_device_register(connector);
>> - if (ret)
>> - return ret;
>> + switch (connector->base.connector_type) {
>> + case DRM_MODE_CONNECTOR_DSI:
>> + ret = intel_backlight_device_register(connector);
>> + if (ret)
>> + return ret;
>> + break;
>> + case DRM_MODE_CONNECTOR_eDP:
>> + intel_edp_backlight_setup(connector);
>> + break;
>> + default:
>> + break;
>> + }
>
> Yeah, this is completely wrong. Setup and register are two different
> phases, and now you'll end up setting up backlight twice and not
> registering it even once for eDP.
>
> This change is not needed.
>
>>
>> - if (connector->base.connector_type == DRM_MODE_CONNECTOR_DSI) {
>> + if (connector->base.connector_type == DRM_MODE_CONNECTOR_DSI ||
>> + connector->base.connector_type == DRM_MODE_CONNECTOR_eDP) {
>> struct device *dev = connector->base.kdev;
>> struct drm_panel *base;
>>
>> @@ -561,6 +571,7 @@ int intel_panel_register(struct intel_connector
>> *connector)
>>
>> err:
>> intel_backlight_device_unregister(connector);
>> + intel_backlight_destroy(panel);
>
> This is the register failure path, you can't call destroy here.
>
>>
>> return ret;
>> }
>> @@ -573,6 +584,7 @@ void intel_panel_unregister(struct intel_connector
>> *connector)
>> drm_panel_remove(panel->base);
>>
>> intel_backlight_device_unregister(connector);
>> + intel_backlight_destroy(panel);
>
> This is the unregister path, you can't call destroy here.
>
>> }
>>
>> /* Notify followers, if any, about power being up. */
>>
>> ---
>> base-commit: 6f72990d9e0fe084afe257621edd730444a8bc52
>> change-id: 20250617-edp_panel-fb90b1c7362a
>>
>> Best regards,
--
Jani Nikula, Intel
