diff mbox series

[SRU,H] drm/i915/dp: Program source OUI on eDP panels

Message ID 20210303131732.8816-4-acelan.kao@canonical.com
State New
Headers show
Series [SRU,H] drm/i915/dp: Program source OUI on eDP panels | expand

Commit Message

AceLan Kao March 3, 2021, 1:17 p.m. UTC
From: Lyude Paul <lyude@redhat.com>

BugLink: https://bugs.launchpad.net/bugs/1917419

Since we're about to start adding support for Intel's magic HDR
backlight interface over DPCD, we need to ensure we're properly
programming this field so that Intel specific sink services are exposed.
Otherwise, 0x300-0x3ff will just read zeroes.

We also take care not to reprogram the source OUI if it already matches
what we expect. This is just to be careful so that we don't accidentally
take the panel out of any backlight control modes we found it in.

v2:
* Add careful parameter to intel_edp_init_source_oui() to avoid
  re-writing the source OUI if it's already been set during driver
  initialization

Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: thaytan@noraisin.net
Cc: Vasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201204223603.249878-2-lyude@redhat.com
(cherry picked from commit f12110afee058a2e6e816e315d3291765625cc87)
Signed-off-by: Chia-Lin Kao (AceLan) <acelan.kao@canonical.com>
---
 drivers/gpu/drm/i915/display/intel_dp.c | 33 +++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

Comments

Andrea Righi March 5, 2021, 3:46 p.m. UTC | #1
Applied to hirsute/5.11.

Thanks,
-Andrea

On Wed, Mar 03, 2021 at 09:17:32PM +0800, AceLan Kao wrote:
> From: Lyude Paul <lyude@redhat.com>
> 
> BugLink: https://bugs.launchpad.net/bugs/1917419
> 
> Since we're about to start adding support for Intel's magic HDR
> backlight interface over DPCD, we need to ensure we're properly
> programming this field so that Intel specific sink services are exposed.
> Otherwise, 0x300-0x3ff will just read zeroes.
> 
> We also take care not to reprogram the source OUI if it already matches
> what we expect. This is just to be careful so that we don't accidentally
> take the panel out of any backlight control modes we found it in.
> 
> v2:
> * Add careful parameter to intel_edp_init_source_oui() to avoid
>   re-writing the source OUI if it's already been set during driver
>   initialization
> 
> Signed-off-by: Lyude Paul <lyude@redhat.com>
> Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Cc: thaytan@noraisin.net
> Cc: Vasily Khoruzhick <anarsoul@gmail.com>
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> Link: https://patchwork.freedesktop.org/patch/msgid/20201204223603.249878-2-lyude@redhat.com
> (cherry picked from commit f12110afee058a2e6e816e315d3291765625cc87)
> Signed-off-by: Chia-Lin Kao (AceLan) <acelan.kao@canonical.com>
> ---
>  drivers/gpu/drm/i915/display/intel_dp.c | 33 +++++++++++++++++++++++++
>  1 file changed, 33 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 8a26307c4896..d46e48941e00 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -3583,6 +3583,29 @@ void intel_dp_sink_set_decompression_state(struct intel_dp *intel_dp,
>  			    enable ? "enable" : "disable");
>  }
>  
> +static void
> +intel_edp_init_source_oui(struct intel_dp *intel_dp, bool careful)
> +{
> +	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
> +	u8 oui[] = { 0x00, 0xaa, 0x01 };
> +	u8 buf[3] = { 0 };
> +
> +	/*
> +	 * During driver init, we want to be careful and avoid changing the source OUI if it's
> +	 * already set to what we want, so as to avoid clearing any state by accident
> +	 */
> +	if (careful) {
> +		if (drm_dp_dpcd_read(&intel_dp->aux, DP_SOURCE_OUI, buf, sizeof(buf)) < 0)
> +			drm_err(&i915->drm, "Failed to read source OUI\n");
> +
> +		if (memcmp(oui, buf, sizeof(oui)) == 0)
> +			return;
> +	}
> +
> +	if (drm_dp_dpcd_write(&intel_dp->aux, DP_SOURCE_OUI, oui, sizeof(oui)) < 0)
> +		drm_err(&i915->drm, "Failed to write source OUI\n");
> +}
> +
>  /* If the device supports it, try to set the power state appropriately */
>  void intel_dp_set_power(struct intel_dp *intel_dp, u8 mode)
>  {
> @@ -3604,6 +3627,10 @@ void intel_dp_set_power(struct intel_dp *intel_dp, u8 mode)
>  
>  		lspcon_resume(dp_to_dig_port(intel_dp));
>  
> +		/* Write the source OUI as early as possible */
> +		if (intel_dp_is_edp(intel_dp))
> +			intel_edp_init_source_oui(intel_dp, false);
> +
>  		/*
>  		 * When turning on, we need to retry for 1ms to give the sink
>  		 * time to wake up.
> @@ -4852,6 +4879,12 @@ intel_edp_init_dpcd(struct intel_dp *intel_dp)
>  	if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv))
>  		intel_dp_get_dsc_sink_cap(intel_dp);
>  
> +	/*
> +	 * If needed, program our source OUI so we can make various Intel-specific AUX services
> +	 * available (such as HDR backlight controls)
> +	 */
> +	intel_edp_init_source_oui(intel_dp, true);
> +
>  	return true;
>  }
>  
> -- 
> 2.25.1
> 
> 
> -- 
> kernel-team mailing list
> kernel-team@lists.ubuntu.com
> https://lists.ubuntu.com/mailman/listinfo/kernel-team
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 8a26307c4896..d46e48941e00 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -3583,6 +3583,29 @@  void intel_dp_sink_set_decompression_state(struct intel_dp *intel_dp,
 			    enable ? "enable" : "disable");
 }
 
+static void
+intel_edp_init_source_oui(struct intel_dp *intel_dp, bool careful)
+{
+	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
+	u8 oui[] = { 0x00, 0xaa, 0x01 };
+	u8 buf[3] = { 0 };
+
+	/*
+	 * During driver init, we want to be careful and avoid changing the source OUI if it's
+	 * already set to what we want, so as to avoid clearing any state by accident
+	 */
+	if (careful) {
+		if (drm_dp_dpcd_read(&intel_dp->aux, DP_SOURCE_OUI, buf, sizeof(buf)) < 0)
+			drm_err(&i915->drm, "Failed to read source OUI\n");
+
+		if (memcmp(oui, buf, sizeof(oui)) == 0)
+			return;
+	}
+
+	if (drm_dp_dpcd_write(&intel_dp->aux, DP_SOURCE_OUI, oui, sizeof(oui)) < 0)
+		drm_err(&i915->drm, "Failed to write source OUI\n");
+}
+
 /* If the device supports it, try to set the power state appropriately */
 void intel_dp_set_power(struct intel_dp *intel_dp, u8 mode)
 {
@@ -3604,6 +3627,10 @@  void intel_dp_set_power(struct intel_dp *intel_dp, u8 mode)
 
 		lspcon_resume(dp_to_dig_port(intel_dp));
 
+		/* Write the source OUI as early as possible */
+		if (intel_dp_is_edp(intel_dp))
+			intel_edp_init_source_oui(intel_dp, false);
+
 		/*
 		 * When turning on, we need to retry for 1ms to give the sink
 		 * time to wake up.
@@ -4852,6 +4879,12 @@  intel_edp_init_dpcd(struct intel_dp *intel_dp)
 	if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv))
 		intel_dp_get_dsc_sink_cap(intel_dp);
 
+	/*
+	 * If needed, program our source OUI so we can make various Intel-specific AUX services
+	 * available (such as HDR backlight controls)
+	 */
+	intel_edp_init_source_oui(intel_dp, true);
+
 	return true;
 }