Re: [PATCH v3 1/1] drm/i915/display: Add quirk to force backlight type on some TUXEDO devices

Am 04.08.26 um 21:52 schrieb Werner Sembach:

> The display backlight on TUXEDO DX1708 and InsanityBook 15 v1 with panels
> AUO 12701 and AUO 12701 must be forced to INTEL_DP_AUX_BACKLIGHT_ON to be
> able to control the brightness.
>
> This could already be archived via a module parameter, but this patch adds
> a quirk to apply this by default on the mentioned devices.
>
> This patch does not actually test for the exact panels as the id that is
> used in the intel_dpcd_quirks list is sadly zeroed on the devices, but
> afaik all these devices use try_intel_interface first anyway so all the
> quirk does is to add the fallback to try_vesa_interface, so the behaviour
> on the devices not needing the quirk and fallback should functionally stay
> the same.
>
> Cc: [email protected]
> Signed-off-by: Werner Sembach <[email protected]>

Fixes: https://gitlab.freedesktop.org/drm/i915/kernel/-/work_items/15679

Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/work_items/15679

> ---
>   .../drm/i915/display/intel_dp_aux_backlight.c |  9 ++++++-
>   drivers/gpu/drm/i915/display/intel_quirks.c   | 24 +++++++++++++++++++
>   drivers/gpu/drm/i915/display/intel_quirks.h   |  1 +
>   3 files changed, 33 insertions(+), 1 deletion(-)
>
> 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 266e042e00237..594c59f2d8309 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> @@ -41,6 +41,7 @@
>   #include "intel_display_types.h"
>   #include "intel_dp.h"
>   #include "intel_dp_aux_backlight.h"
> +#include "intel_quirks.h"
>   
>   /*
>    * DP AUX registers for Intel's proprietary HDR backlight interface. We define
> @@ -687,11 +688,17 @@ int intel_dp_aux_init_backlight_funcs(struct intel_connector *connector)
>   	struct drm_device *dev = connector->base.dev;
>   	struct intel_panel *panel = &connector->panel;
>   	bool try_intel_interface = false, try_vesa_interface = false;
> +	int enable_dpcd_backlight;
>   
>   	/* Check the VBT and user's module parameters to figure out which
>   	 * interfaces to probe
>   	 */
> -	switch (display->params.enable_dpcd_backlight) {
> +	enable_dpcd_backlight = display->params.enable_dpcd_backlight;
> +	if (enable_dpcd_backlight == INTEL_DP_AUX_BACKLIGHT_AUTO &&
> +	    intel_has_dpcd_quirk(intel_dp, QUIRK_ENABLE_DPCD_BACKLIGHT))
> +		enable_dpcd_backlight = INTEL_DP_AUX_BACKLIGHT_ON;
> +
> +	switch (enable_dpcd_backlight) {
>   	case INTEL_DP_AUX_BACKLIGHT_OFF:
>   		return -ENODEV;
>   	case INTEL_DP_AUX_BACKLIGHT_AUTO:
> diff --git a/drivers/gpu/drm/i915/display/intel_quirks.c b/drivers/gpu/drm/i915/display/intel_quirks.c
> index 33245f44c0d50..89d82364ae45d 100644
> --- a/drivers/gpu/drm/i915/display/intel_quirks.c
> +++ b/drivers/gpu/drm/i915/display/intel_quirks.c
> @@ -100,6 +100,14 @@ static void quirk_disable_psr2(struct intel_display *display)
>   	drm_info(display->drm, "PSR2 support not currently available for this setup, applying disable PSR2 quirk\n");
>   }
>   
> +static void quirk_enable_dpcd_backlight(struct intel_dp *intel_dp)
> +{
> +	struct intel_display *display = to_intel_display(intel_dp);
> +
> +	intel_set_dpcd_quirk(intel_dp, QUIRK_ENABLE_DPCD_BACKLIGHT);
> +	drm_info(display->drm, "Applying Enable DPCD Backlight quirk\n");
> +}
> +
>   struct intel_quirk {
>   	int device;
>   	int subsystem_vendor;
> @@ -286,6 +294,22 @@ static const struct intel_dpcd_quirk intel_dpcd_quirks[] = {
>   		.sink_oui = SINK_OUI(0x00, 0x22, 0xb9),
>   		.hook = quirk_disable_edp_panel_replay,
>   	},
> +	/* TUXEDO InsanityBook 15 v1 */
> +	{
> +		.device = 0x591b,
> +		.subsystem_vendor = 0x1558,
> +		.subsystem_device = 0x9501,
> +		.sink_oui = SINK_OUI(0x38, 0xec, 0x11),
> +		.hook = quirk_enable_dpcd_backlight,
> +	},
> +	/* TUXEDO DX1708 */
> +	{
> +		.device = 0x3e9b,
> +		.subsystem_vendor = 0x1558,
> +		.subsystem_device = 0x8500,
> +		.sink_oui = SINK_OUI(0x38, 0xec, 0x11),
> +		.hook = quirk_enable_dpcd_backlight,
> +	},
>   };
>   
>   void intel_init_quirks(struct intel_display *display)
> diff --git a/drivers/gpu/drm/i915/display/intel_quirks.h b/drivers/gpu/drm/i915/display/intel_quirks.h
> index 970a4fe52fafc..4996419ae76bd 100644
> --- a/drivers/gpu/drm/i915/display/intel_quirks.h
> +++ b/drivers/gpu/drm/i915/display/intel_quirks.h
> @@ -23,6 +23,7 @@ enum intel_quirk_id {
>   	QUIRK_EDP_LIMIT_RATE_HBR2,
>   	QUIRK_DISABLE_EDP_PANEL_REPLAY,
>   	QUIRK_DISABLE_PSR2,
> +	QUIRK_ENABLE_DPCD_BACKLIGHT,
>   };
>   
>   void intel_init_quirks(struct intel_display *display);