[PATCH v6 0/4] drm: Minimum backlight overrides and implementation for amdgpu

[PATCH v6 0/4] drm: Minimum backlight overrides and implementation for amdgpu

[Thomas Weißschuh]

The value of "min_input_signal" returned from ATIF on a Framework AMD 13
is "12". This leads to a fairly bright minimum display backlight.

Introduce a quirk to override "min_input_signal" to "0" which leads to a
much lower minimum brightness, which is still readable even in daylight.

One solution would be a fixed firmware version, which was announced but
has no timeline.

---
Changes in v6:
- Clean up cover letter and commit messages
- Add my S-o-b to patch from Dustin
- Mention testing in combination with "panel_power_savings"
- Link to v5: https://lore.kernel.org/r/20240818-amdgpu-min-backlight-quirk-v5-0-b6c0ead0c73d@weissschuh.net

Changes in v5:
- Forward-declare struct drm_edid
- Reorder patches, quirk entries are last
- Add patch from Dustin for additional quirk entries
- Link to v4: https://lore.kernel.org/r/20240812-amdgpu-min-backlight-quirk-v4-0-56a63ff897b7@weissschuh.net

Changes in v4:
- Switch back to v2 implementation
- Add MODULE_DESCRIPTION()
- Simplify quirk infrastructure to only handle min backlight quirks.
  It can be extended if necessary.
- Expand documentation.
- Link to v3: https://lore.kernel.org/r/20240731-amdgpu-min-backlight-quirk-v3-0-46d40bb21a62@weissschuh.net

Changes in v3:
- Switch to cmdline override parameter
- Link to v2: https://lore.kernel.org/r/20240623-amdgpu-min-backlight-quirk-v2-0-cecf7f49da9b@weissschuh.net

Changes in v2:
- Introduce proper drm backlight quirk infrastructure
- Quirk by EDID and DMI instead of only DMI
- Limit quirk to only single Framework 13 matte panel
- Link to v1: https://lore.kernel.org/r/20240610-amdgpu-min-backlight-quirk-v1-1-8459895a5b2a@weissschuh.net

---
Dustin L. Howett (1):
      drm: panel-backlight-quirks: Add Framework 13 glossy and 2.8k panels

Thomas Weißschuh (3):
      drm: Add panel backlight quirks
      drm/amd/display: Add support for minimum backlight quirk
      drm: panel-backlight-quirks: Add Framework 13 matte panel

 Documentation/gpu/drm-kms-helpers.rst             |  3 +
 drivers/gpu/drm/Kconfig                           |  4 +
 drivers/gpu/drm/Makefile                          |  1 +
 drivers/gpu/drm/amd/amdgpu/Kconfig                |  1 +
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 10 +++
 drivers/gpu/drm/drm_panel_backlight_quirks.c      | 94 +++++++++++++++++++++++
 include/drm/drm_utils.h                           |  4 +
 7 files changed, 117 insertions(+)
---
base-commit: d2bafcf224f3911b183113b2fcb536c9e90684a3
change-id: 20240610-amdgpu-min-backlight-quirk-8402fd8e736a

Best regards,
-- 
Thomas Weißschuh <linux@weissschuh.net>

[PATCH v6 1/4] drm: Add panel backlight quirks

[Thomas Weißschuh]

Panels using a PWM-controlled backlight source do not have a standard
way to communicate their valid PWM ranges.
On x86 the ranges are read from ACPI through driver-specific tables.
The built-in ranges are not necessarily correct, or may grow stale if an
older device can be retrofitted with newer panels.

Add a quirk infrastructure with which the minimum valid backlight value
can be maintained as part of the kernel.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Tested-by: Dustin L. Howett <dustin@howett.net>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
---
 Documentation/gpu/drm-kms-helpers.rst        |  3 ++
 drivers/gpu/drm/Kconfig                      |  4 ++
 drivers/gpu/drm/Makefile                     |  1 +
 drivers/gpu/drm/drm_panel_backlight_quirks.c | 70 ++++++++++++++++++++++++++++
 include/drm/drm_utils.h                      |  4 ++
 5 files changed, 82 insertions(+)

diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst
index 8435e8621cc0..a26989500129 100644
--- a/Documentation/gpu/drm-kms-helpers.rst
+++ b/Documentation/gpu/drm-kms-helpers.rst
@@ -230,6 +230,9 @@ Panel Helper Reference
 .. kernel-doc:: drivers/gpu/drm/drm_panel_orientation_quirks.c
    :export:
 
+.. kernel-doc:: drivers/gpu/drm/drm_panel_backlight_quirks.c
+   :export:
+
 Panel Self Refresh Helper Reference
 ===================================
 
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 6b2c6b91f962..9ebb8cdb535e 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -454,6 +454,10 @@ config DRM_HYPERV
 config DRM_EXPORT_FOR_TESTS
 	bool
 
+# Separate option as not all DRM drivers use it
+config DRM_PANEL_BACKLIGHT_QUIRKS
+	tristate
+
 config DRM_LIB_RANDOM
 	bool
 	default n
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 68cc9258ffc4..adf85999aee2 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -92,6 +92,7 @@ drm-$(CONFIG_DRM_PANIC) += drm_panic.o
 obj-$(CONFIG_DRM)	+= drm.o
 
 obj-$(CONFIG_DRM_PANEL_ORIENTATION_QUIRKS) += drm_panel_orientation_quirks.o
+obj-$(CONFIG_DRM_PANEL_BACKLIGHT_QUIRKS) += drm_panel_backlight_quirks.o
 
 #
 # Memory-management helpers
diff --git a/drivers/gpu/drm/drm_panel_backlight_quirks.c b/drivers/gpu/drm/drm_panel_backlight_quirks.c
new file mode 100644
index 000000000000..6b8bbed77c7f
--- /dev/null
+++ b/drivers/gpu/drm/drm_panel_backlight_quirks.c
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/array_size.h>
+#include <linux/dmi.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <drm/drm_edid.h>
+#include <drm/drm_utils.h>
+
+struct drm_panel_min_backlight_quirk {
+	struct {
+		enum dmi_field field;
+		const char * const value;
+	} dmi_match;
+	struct drm_edid_ident ident;
+	u8 min_brightness;
+};
+
+static const struct drm_panel_min_backlight_quirk drm_panel_min_backlight_quirks[] = {
+};
+
+static bool drm_panel_min_backlight_quirk_matches(const struct drm_panel_min_backlight_quirk *quirk,
+						  const struct drm_edid *edid)
+{
+	if (!dmi_match(quirk->dmi_match.field, quirk->dmi_match.value))
+		return false;
+
+	if (!drm_edid_match(edid, &quirk->ident))
+		return false;
+
+	return true;
+}
+
+/**
+ * drm_get_panel_min_brightness_quirk - Get minimum supported brightness level for a panel.
+ * @edid: EDID of the panel to check
+ *
+ * This function checks for platform specific (e.g. DMI based) quirks
+ * providing info on the minimum backlight brightness for systems where this
+ * cannot be probed correctly from the hard-/firm-ware.
+ *
+ * Returns:
+ * A negative error value or
+ * an override value in the range [0, 255] representing 0-100% to be scaled to
+ * the drivers target range.
+ */
+int drm_get_panel_min_brightness_quirk(const struct drm_edid *edid)
+{
+	const struct drm_panel_min_backlight_quirk *quirk;
+	size_t i;
+
+	if (!IS_ENABLED(CONFIG_DMI))
+		return -ENODATA;
+
+	if (!edid)
+		return -EINVAL;
+
+	for (i = 0; i < ARRAY_SIZE(drm_panel_min_backlight_quirks); i++) {
+		quirk = &drm_panel_min_backlight_quirks[i];
+
+		if (drm_panel_min_backlight_quirk_matches(quirk, edid))
+			return quirk->min_brightness;
+	}
+
+	return -ENODATA;
+}
+EXPORT_SYMBOL(drm_get_panel_min_brightness_quirk);
+
+MODULE_DESCRIPTION("Quirks for panel backlight overrides");
+MODULE_LICENSE("GPL");
diff --git a/include/drm/drm_utils.h b/include/drm/drm_utils.h
index 70775748d243..15fa9b6865f4 100644
--- a/include/drm/drm_utils.h
+++ b/include/drm/drm_utils.h
@@ -12,8 +12,12 @@
 
 #include <linux/types.h>
 
+struct drm_edid;
+
 int drm_get_panel_orientation_quirk(int width, int height);
 
+int drm_get_panel_min_brightness_quirk(const struct drm_edid *edid);
+
 signed long drm_timeout_abs_to_jiffies(int64_t timeout_nsec);
 
 #endif

-- 
2.46.0

[PATCH v6 2/4] drm/amd/display: Add support for minimum backlight quirk

[Thomas Weißschuh]

Not all platforms provide the full range of PWM backlight capabilities
supported by the hardware through ATIF.
Use the generic drm panel minimum backlight quirk infrastructure to
override the capabilities where necessary.

Testing the backlight quirk together with the "panel_power_savings"
sysfs file has not shown any negative impact.
One quirk seems to be that 0% at panel_power_savings=0 seems to be
slightly darker than at panel_power_savings=4.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Tested-by: Dustin L. Howett <dustin@howett.net>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/Kconfig                |  1 +
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 10 ++++++++++
 2 files changed, 11 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/Kconfig b/drivers/gpu/drm/amd/amdgpu/Kconfig
index 0051fb1b437f..655c10aef2e3 100644
--- a/drivers/gpu/drm/amd/amdgpu/Kconfig
+++ b/drivers/gpu/drm/amd/amdgpu/Kconfig
@@ -23,6 +23,7 @@ config DRM_AMDGPU
 	select DRM_BUDDY
 	select DRM_SUBALLOC_HELPER
 	select DRM_EXEC
+	select DRM_PANEL_BACKLIGHT_QUIRKS
 	# amdgpu depends on ACPI_VIDEO when ACPI is enabled, for select to work
 	# ACPI_VIDEO's dependencies must also be selected.
 	select INPUT if ACPI
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 983a977632ff..056960ea335c 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -93,6 +93,7 @@
 #include <drm/drm_fourcc.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_eld.h>
+#include <drm/drm_utils.h>
 #include <drm/drm_vblank.h>
 #include <drm/drm_audio_component.h>
 #include <drm/drm_gem_atomic_helper.h>
@@ -3333,6 +3334,8 @@ static void update_connector_ext_caps(struct amdgpu_dm_connector *aconnector)
 	struct drm_connector *conn_base;
 	struct amdgpu_device *adev;
 	struct drm_luminance_range_info *luminance_range;
+	const struct drm_edid *drm_edid;
+	int min_input_signal_override;
 
 	if (aconnector->bl_idx == -1 ||
 	    aconnector->dc_link->connector_signal != SIGNAL_TYPE_EDP)
@@ -3367,6 +3370,13 @@ static void update_connector_ext_caps(struct amdgpu_dm_connector *aconnector)
 		caps->aux_min_input_signal = 0;
 		caps->aux_max_input_signal = 512;
 	}
+
+	drm_edid = drm_edid_alloc(aconnector->edid,
+				  EDID_LENGTH * (aconnector->edid->extensions + 1));
+	min_input_signal_override = drm_get_panel_min_brightness_quirk(drm_edid);
+	drm_edid_free(drm_edid);
+	if (min_input_signal_override >= 0)
+		caps->min_input_signal = min_input_signal_override;
 }
 
 void amdgpu_dm_update_connector_after_detect(

-- 
2.46.0

Re: [PATCH v6 2/4] drm/amd/display: Add support for minimum backlight quirk

[Mario Limonciello]

On 8/24/2024 13:33, Thomas Weißschuh wrote:
> Not all platforms provide the full range of PWM backlight capabilities
> supported by the hardware through ATIF.
> Use the generic drm panel minimum backlight quirk infrastructure to
> override the capabilities where necessary.
> 
> Testing the backlight quirk together with the "panel_power_savings"
> sysfs file has not shown any negative impact.
> One quirk seems to be that 0% at panel_power_savings=0 seems to be
> slightly darker than at panel_power_savings=4.

Thanks; This is the kind of thing I was worried about.

Harry, Leo,

Is that expected?  I wonder if we need to internally turn off panel 
power savings in display code when brightness falls a threshold (12 IIRC 
was the real "minimum" advertised in the table?).

> 
> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
> Tested-by: Dustin L. Howett <dustin@howett.net>
> Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/Kconfig                |  1 +
>   drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 10 ++++++++++
>   2 files changed, 11 insertions(+)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/Kconfig b/drivers/gpu/drm/amd/amdgpu/Kconfig
> index 0051fb1b437f..655c10aef2e3 100644
> --- a/drivers/gpu/drm/amd/amdgpu/Kconfig
> +++ b/drivers/gpu/drm/amd/amdgpu/Kconfig
> @@ -23,6 +23,7 @@ config DRM_AMDGPU
>   	select DRM_BUDDY
>   	select DRM_SUBALLOC_HELPER
>   	select DRM_EXEC
> +	select DRM_PANEL_BACKLIGHT_QUIRKS
>   	# amdgpu depends on ACPI_VIDEO when ACPI is enabled, for select to work
>   	# ACPI_VIDEO's dependencies must also be selected.
>   	select INPUT if ACPI
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> index 983a977632ff..056960ea335c 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -93,6 +93,7 @@
>   #include <drm/drm_fourcc.h>
>   #include <drm/drm_edid.h>
>   #include <drm/drm_eld.h>
> +#include <drm/drm_utils.h>
>   #include <drm/drm_vblank.h>
>   #include <drm/drm_audio_component.h>
>   #include <drm/drm_gem_atomic_helper.h>
> @@ -3333,6 +3334,8 @@ static void update_connector_ext_caps(struct amdgpu_dm_connector *aconnector)
>   	struct drm_connector *conn_base;
>   	struct amdgpu_device *adev;
>   	struct drm_luminance_range_info *luminance_range;
> +	const struct drm_edid *drm_edid;
> +	int min_input_signal_override;
>   
>   	if (aconnector->bl_idx == -1 ||
>   	    aconnector->dc_link->connector_signal != SIGNAL_TYPE_EDP)
> @@ -3367,6 +3370,13 @@ static void update_connector_ext_caps(struct amdgpu_dm_connector *aconnector)
>   		caps->aux_min_input_signal = 0;
>   		caps->aux_max_input_signal = 512;
>   	}
> +
> +	drm_edid = drm_edid_alloc(aconnector->edid,
> +				  EDID_LENGTH * (aconnector->edid->extensions + 1));
> +	min_input_signal_override = drm_get_panel_min_brightness_quirk(drm_edid);
> +	drm_edid_free(drm_edid);
> +	if (min_input_signal_override >= 0)
> +		caps->min_input_signal = min_input_signal_override;
>   }
>   
>   void amdgpu_dm_update_connector_after_detect(
> 

Re: [PATCH v6 2/4] drm/amd/display: Add support for minimum backlight quirk

[Harry Wentland]

On 2024-08-26 12:57, Mario Limonciello wrote:
> On 8/24/2024 13:33, Thomas Weißschuh wrote:
>> Not all platforms provide the full range of PWM backlight capabilities
>> supported by the hardware through ATIF.
>> Use the generic drm panel minimum backlight quirk infrastructure to
>> override the capabilities where necessary.
>>
>> Testing the backlight quirk together with the "panel_power_savings"
>> sysfs file has not shown any negative impact.
>> One quirk seems to be that 0% at panel_power_savings=0 seems to be
>> slightly darker than at panel_power_savings=4.
> 
> Thanks; This is the kind of thing I was worried about.
> 
> Harry, Leo,
> 
> Is that expected?  I wonder if we need to internally turn off panel power savings in display code when brightness falls a threshold (12 IIRC was the real "minimum" advertised in the table?).

How much darker? Is it bothersome?

I wonder the FW and driver have different min backlight values now.

Leo, any thoughts?

Harry

> 
>>
>> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
>> Tested-by: Dustin L. Howett <dustin@howett.net>
>> Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/Kconfig                |  1 +
>>   drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 10 ++++++++++
>>   2 files changed, 11 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/Kconfig b/drivers/gpu/drm/amd/amdgpu/Kconfig
>> index 0051fb1b437f..655c10aef2e3 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/Kconfig
>> +++ b/drivers/gpu/drm/amd/amdgpu/Kconfig
>> @@ -23,6 +23,7 @@ config DRM_AMDGPU
>>       select DRM_BUDDY
>>       select DRM_SUBALLOC_HELPER
>>       select DRM_EXEC
>> +    select DRM_PANEL_BACKLIGHT_QUIRKS
>>       # amdgpu depends on ACPI_VIDEO when ACPI is enabled, for select to work
>>       # ACPI_VIDEO's dependencies must also be selected.
>>       select INPUT if ACPI
>> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> index 983a977632ff..056960ea335c 100644
>> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> @@ -93,6 +93,7 @@
>>   #include <drm/drm_fourcc.h>
>>   #include <drm/drm_edid.h>
>>   #include <drm/drm_eld.h>
>> +#include <drm/drm_utils.h>
>>   #include <drm/drm_vblank.h>
>>   #include <drm/drm_audio_component.h>
>>   #include <drm/drm_gem_atomic_helper.h>
>> @@ -3333,6 +3334,8 @@ static void update_connector_ext_caps(struct amdgpu_dm_connector *aconnector)
>>       struct drm_connector *conn_base;
>>       struct amdgpu_device *adev;
>>       struct drm_luminance_range_info *luminance_range;
>> +    const struct drm_edid *drm_edid;
>> +    int min_input_signal_override;
>>         if (aconnector->bl_idx == -1 ||
>>           aconnector->dc_link->connector_signal != SIGNAL_TYPE_EDP)
>> @@ -3367,6 +3370,13 @@ static void update_connector_ext_caps(struct amdgpu_dm_connector *aconnector)
>>           caps->aux_min_input_signal = 0;
>>           caps->aux_max_input_signal = 512;
>>       }
>> +
>> +    drm_edid = drm_edid_alloc(aconnector->edid,
>> +                  EDID_LENGTH * (aconnector->edid->extensions + 1));
>> +    min_input_signal_override = drm_get_panel_min_brightness_quirk(drm_edid);
>> +    drm_edid_free(drm_edid);
>> +    if (min_input_signal_override >= 0)
>> +        caps->min_input_signal = min_input_signal_override;
>>   }
>>     void amdgpu_dm_update_connector_after_detect(
>>
> 

Re: [PATCH v6 2/4] drm/amd/display: Add support for minimum backlight quirk

[Thomas Weißschuh]

On 2024-09-16 15:43:35-0400, Harry Wentland wrote:
> On 2024-08-26 12:57, Mario Limonciello wrote:
> > On 8/24/2024 13:33, Thomas Weißschuh wrote:
> >> Not all platforms provide the full range of PWM backlight capabilities
> >> supported by the hardware through ATIF.
> >> Use the generic drm panel minimum backlight quirk infrastructure to
> >> override the capabilities where necessary.
> >>
> >> Testing the backlight quirk together with the "panel_power_savings"
> >> sysfs file has not shown any negative impact.
> >> One quirk seems to be that 0% at panel_power_savings=0 seems to be
> >> slightly darker than at panel_power_savings=4.
> > 
> > Thanks; This is the kind of thing I was worried about.
> > 
> > Harry, Leo,
> > 
> > Is that expected?  I wonder if we need to internally turn off panel
> > power savings in display code when brightness falls a threshold (12
> > IIRC was the real "minimum" advertised in the table?).
> 
> How much darker? Is it bothersome?

Was this questions for meant for me?
To me personally it's absolutely not bothersome.
I probably wouldn't have noticed it if not explicitly looking for it.

> I wonder the FW and driver have different min backlight values now.
> 
> Leo, any thoughts?

Friendly ping.

[PATCH v6 3/4] drm: panel-backlight-quirks: Add Framework 13 matte panel

[Thomas Weißschuh]

The value of "min_input_signal" returned from ATIF on a Framework AMD 13
is "12". This leads to a fairly bright minimum display backlight.

Add a quirk to override that the minimum backlight PWM to "0" which
leads to a much lower minimum brightness, which is still visible.

Tested on a Framework AMD 13 BIOS 3.05 with the matte panel.

Link: https://community.frame.work/t/25711/9
Link: https://community.frame.work/t/47036
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Tested-by: Dustin L. Howett <dustin@howett.net>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/gpu/drm/drm_panel_backlight_quirks.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/drm_panel_backlight_quirks.c b/drivers/gpu/drm/drm_panel_backlight_quirks.c
index 6b8bbed77c7f..f2aefff618dd 100644
--- a/drivers/gpu/drm/drm_panel_backlight_quirks.c
+++ b/drivers/gpu/drm/drm_panel_backlight_quirks.c
@@ -17,6 +17,14 @@ struct drm_panel_min_backlight_quirk {
 };
 
 static const struct drm_panel_min_backlight_quirk drm_panel_min_backlight_quirks[] = {
+	/* 13 inch matte panel */
+	{
+		.dmi_match.field = DMI_BOARD_VENDOR,
+		.dmi_match.value = "Framework",
+		.ident.panel_id = drm_edid_encode_panel_id('B', 'O', 'E', 0x0bca),
+		.ident.name = "NE135FBM-N41",
+		.min_brightness = 0,
+	},
 };
 
 static bool drm_panel_min_backlight_quirk_matches(const struct drm_panel_min_backlight_quirk *quirk,

-- 
2.46.0

[PATCH v6 4/4] drm: panel-backlight-quirks: Add Framework 13 glossy and 2.8k panels

[Thomas Weißschuh]

From: "Dustin L. Howett" <dustin@howett.net>

I have tested these panels on the Framework Laptop 13 AMD with firmware
revision 3.05 (latest at time of submission).

Signed-off-by: Dustin L. Howett <dustin@howett.net>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/gpu/drm/drm_panel_backlight_quirks.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/gpu/drm/drm_panel_backlight_quirks.c b/drivers/gpu/drm/drm_panel_backlight_quirks.c
index f2aefff618dd..c477d98ade2b 100644
--- a/drivers/gpu/drm/drm_panel_backlight_quirks.c
+++ b/drivers/gpu/drm/drm_panel_backlight_quirks.c
@@ -25,6 +25,22 @@ static const struct drm_panel_min_backlight_quirk drm_panel_min_backlight_quirks
 		.ident.name = "NE135FBM-N41",
 		.min_brightness = 0,
 	},
+	/* 13 inch glossy panel */
+	{
+		.dmi_match.field = DMI_BOARD_VENDOR,
+		.dmi_match.value = "Framework",
+		.ident.panel_id = drm_edid_encode_panel_id('B', 'O', 'E', 0x095f),
+		.ident.name = "NE135FBM-N41",
+		.min_brightness = 0,
+	},
+	/* 13 inch 2.8k panel */
+	{
+		.dmi_match.field = DMI_BOARD_VENDOR,
+		.dmi_match.value = "Framework",
+		.ident.panel_id = drm_edid_encode_panel_id('B', 'O', 'E', 0x0cb4),
+		.ident.name = "NE135A1M-NY1",
+		.min_brightness = 0,
+	},
 };
 
 static bool drm_panel_min_backlight_quirk_matches(const struct drm_panel_min_backlight_quirk *quirk,

-- 
2.46.0

Re: [PATCH v6 0/4] drm: Minimum backlight overrides and implementation for amdgpu

[Thomas Weißschuh]

Hi Harry, Leo and other amdgpu maintainers,

On 2024-08-24 20:33:53+0000, Thomas Weißschuh wrote:
> The value of "min_input_signal" returned from ATIF on a Framework AMD 13
> is "12". This leads to a fairly bright minimum display backlight.
> 
> Introduce a quirk to override "min_input_signal" to "0" which leads to a
> much lower minimum brightness, which is still readable even in daylight.

could you take another look at the series?
The issues around panel power are not specific to the low pwm values,
so shouldn't have an impact on this series.
(And are nearly imperceptible anyways)

> One solution would be a fixed firmware version, which was announced but
> has no timeline.
> 
> ---
> Changes in v6:
> - Clean up cover letter and commit messages
> - Add my S-o-b to patch from Dustin
> - Mention testing in combination with "panel_power_savings"
> - Link to v5: https://lore.kernel.org/r/20240818-amdgpu-min-backlight-quirk-v5-0-b6c0ead0c73d@weissschuh.net
> 
> Changes in v5:
> - Forward-declare struct drm_edid
> - Reorder patches, quirk entries are last
> - Add patch from Dustin for additional quirk entries
> - Link to v4: https://lore.kernel.org/r/20240812-amdgpu-min-backlight-quirk-v4-0-56a63ff897b7@weissschuh.net
> 
> Changes in v4:
> - Switch back to v2 implementation
> - Add MODULE_DESCRIPTION()
> - Simplify quirk infrastructure to only handle min backlight quirks.
>   It can be extended if necessary.
> - Expand documentation.
> - Link to v3: https://lore.kernel.org/r/20240731-amdgpu-min-backlight-quirk-v3-0-46d40bb21a62@weissschuh.net
> 
> Changes in v3:
> - Switch to cmdline override parameter
> - Link to v2: https://lore.kernel.org/r/20240623-amdgpu-min-backlight-quirk-v2-0-cecf7f49da9b@weissschuh.net
> 
> Changes in v2:
> - Introduce proper drm backlight quirk infrastructure
> - Quirk by EDID and DMI instead of only DMI
> - Limit quirk to only single Framework 13 matte panel
> - Link to v1: https://lore.kernel.org/r/20240610-amdgpu-min-backlight-quirk-v1-1-8459895a5b2a@weissschuh.net
> 
> ---
> Dustin L. Howett (1):
>       drm: panel-backlight-quirks: Add Framework 13 glossy and 2.8k panels
> 
> Thomas Weißschuh (3):
>       drm: Add panel backlight quirks
>       drm/amd/display: Add support for minimum backlight quirk
>       drm: panel-backlight-quirks: Add Framework 13 matte panel
> 
>  Documentation/gpu/drm-kms-helpers.rst             |  3 +
>  drivers/gpu/drm/Kconfig                           |  4 +
>  drivers/gpu/drm/Makefile                          |  1 +
>  drivers/gpu/drm/amd/amdgpu/Kconfig                |  1 +
>  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 10 +++
>  drivers/gpu/drm/drm_panel_backlight_quirks.c      | 94 +++++++++++++++++++++++
>  include/drm/drm_utils.h                           |  4 +
>  7 files changed, 117 insertions(+)
> ---
> base-commit: d2bafcf224f3911b183113b2fcb536c9e90684a3
> change-id: 20240610-amdgpu-min-backlight-quirk-8402fd8e736a
> 
> Best regards,
> -- 
> Thomas Weißschuh <linux@weissschuh.net>
> 

Re: [PATCH v6 0/4] drm: Minimum backlight overrides and implementation for amdgpu

[Harry Wentland]

On 2024-09-16 14:23, Thomas Weißschuh wrote:
> Hi Harry, Leo and other amdgpu maintainers,
> 
> On 2024-08-24 20:33:53+0000, Thomas Weißschuh wrote:
>> The value of "min_input_signal" returned from ATIF on a Framework AMD 13
>> is "12". This leads to a fairly bright minimum display backlight.
>>
>> Introduce a quirk to override "min_input_signal" to "0" which leads to a
>> much lower minimum brightness, which is still readable even in daylight.
> 
> could you take another look at the series?
> The issues around panel power are not specific to the low pwm values,
> so shouldn't have an impact on this series.
> (And are nearly imperceptible anyways)
> 

I think these patches are good.

Reviewed-by: Harry Wentland <harry.wentland@amd.com>

Harry

>> One solution would be a fixed firmware version, which was announced but
>> has no timeline.
>>
>> ---
>> Changes in v6:
>> - Clean up cover letter and commit messages
>> - Add my S-o-b to patch from Dustin
>> - Mention testing in combination with "panel_power_savings"
>> - Link to v5: https://lore.kernel.org/r/20240818-amdgpu-min-backlight-quirk-v5-0-b6c0ead0c73d@weissschuh.net
>>
>> Changes in v5:
>> - Forward-declare struct drm_edid
>> - Reorder patches, quirk entries are last
>> - Add patch from Dustin for additional quirk entries
>> - Link to v4: https://lore.kernel.org/r/20240812-amdgpu-min-backlight-quirk-v4-0-56a63ff897b7@weissschuh.net
>>
>> Changes in v4:
>> - Switch back to v2 implementation
>> - Add MODULE_DESCRIPTION()
>> - Simplify quirk infrastructure to only handle min backlight quirks.
>>   It can be extended if necessary.
>> - Expand documentation.
>> - Link to v3: https://lore.kernel.org/r/20240731-amdgpu-min-backlight-quirk-v3-0-46d40bb21a62@weissschuh.net
>>
>> Changes in v3:
>> - Switch to cmdline override parameter
>> - Link to v2: https://lore.kernel.org/r/20240623-amdgpu-min-backlight-quirk-v2-0-cecf7f49da9b@weissschuh.net
>>
>> Changes in v2:
>> - Introduce proper drm backlight quirk infrastructure
>> - Quirk by EDID and DMI instead of only DMI
>> - Limit quirk to only single Framework 13 matte panel
>> - Link to v1: https://lore.kernel.org/r/20240610-amdgpu-min-backlight-quirk-v1-1-8459895a5b2a@weissschuh.net
>>
>> ---
>> Dustin L. Howett (1):
>>       drm: panel-backlight-quirks: Add Framework 13 glossy and 2.8k panels
>>
>> Thomas Weißschuh (3):
>>       drm: Add panel backlight quirks
>>       drm/amd/display: Add support for minimum backlight quirk
>>       drm: panel-backlight-quirks: Add Framework 13 matte panel
>>
>>  Documentation/gpu/drm-kms-helpers.rst             |  3 +
>>  drivers/gpu/drm/Kconfig                           |  4 +
>>  drivers/gpu/drm/Makefile                          |  1 +
>>  drivers/gpu/drm/amd/amdgpu/Kconfig                |  1 +
>>  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 10 +++
>>  drivers/gpu/drm/drm_panel_backlight_quirks.c      | 94 +++++++++++++++++++++++
>>  include/drm/drm_utils.h                           |  4 +
>>  7 files changed, 117 insertions(+)
>> ---
>> base-commit: d2bafcf224f3911b183113b2fcb536c9e90684a3
>> change-id: 20240610-amdgpu-min-backlight-quirk-8402fd8e736a
>>
>> Best regards,
>> -- 
>> Thomas Weißschuh <linux@weissschuh.net>
>>

Re: [PATCH v6 0/4] drm: Minimum backlight overrides and implementation for amdgpu

[Alex Deucher]

On Wed, Oct 16, 2024 at 1:47 PM Harry Wentland <harry.wentland@amd.com> wrote:
>
>
>
> On 2024-09-16 14:23, Thomas Weißschuh wrote:
> > Hi Harry, Leo and other amdgpu maintainers,
> >
> > On 2024-08-24 20:33:53+0000, Thomas Weißschuh wrote:
> >> The value of "min_input_signal" returned from ATIF on a Framework AMD 13
> >> is "12". This leads to a fairly bright minimum display backlight.
> >>
> >> Introduce a quirk to override "min_input_signal" to "0" which leads to a
> >> much lower minimum brightness, which is still readable even in daylight.
> >
> > could you take another look at the series?
> > The issues around panel power are not specific to the low pwm values,
> > so shouldn't have an impact on this series.
> > (And are nearly imperceptible anyways)
> >
>
> I think these patches are good.
>
> Reviewed-by: Harry Wentland <harry.wentland@amd.com>

Can you pick these up?

Thanks,

Alex

>
> Harry
>
> >> One solution would be a fixed firmware version, which was announced but
> >> has no timeline.
> >>
> >> ---
> >> Changes in v6:
> >> - Clean up cover letter and commit messages
> >> - Add my S-o-b to patch from Dustin
> >> - Mention testing in combination with "panel_power_savings"
> >> - Link to v5: https://lore.kernel.org/r/20240818-amdgpu-min-backlight-quirk-v5-0-b6c0ead0c73d@weissschuh.net
> >>
> >> Changes in v5:
> >> - Forward-declare struct drm_edid
> >> - Reorder patches, quirk entries are last
> >> - Add patch from Dustin for additional quirk entries
> >> - Link to v4: https://lore.kernel.org/r/20240812-amdgpu-min-backlight-quirk-v4-0-56a63ff897b7@weissschuh.net
> >>
> >> Changes in v4:
> >> - Switch back to v2 implementation
> >> - Add MODULE_DESCRIPTION()
> >> - Simplify quirk infrastructure to only handle min backlight quirks.
> >>   It can be extended if necessary.
> >> - Expand documentation.
> >> - Link to v3: https://lore.kernel.org/r/20240731-amdgpu-min-backlight-quirk-v3-0-46d40bb21a62@weissschuh.net
> >>
> >> Changes in v3:
> >> - Switch to cmdline override parameter
> >> - Link to v2: https://lore.kernel.org/r/20240623-amdgpu-min-backlight-quirk-v2-0-cecf7f49da9b@weissschuh.net
> >>
> >> Changes in v2:
> >> - Introduce proper drm backlight quirk infrastructure
> >> - Quirk by EDID and DMI instead of only DMI
> >> - Limit quirk to only single Framework 13 matte panel
> >> - Link to v1: https://lore.kernel.org/r/20240610-amdgpu-min-backlight-quirk-v1-1-8459895a5b2a@weissschuh.net
> >>
> >> ---
> >> Dustin L. Howett (1):
> >>       drm: panel-backlight-quirks: Add Framework 13 glossy and 2.8k panels
> >>
> >> Thomas Weißschuh (3):
> >>       drm: Add panel backlight quirks
> >>       drm/amd/display: Add support for minimum backlight quirk
> >>       drm: panel-backlight-quirks: Add Framework 13 matte panel
> >>
> >>  Documentation/gpu/drm-kms-helpers.rst             |  3 +
> >>  drivers/gpu/drm/Kconfig                           |  4 +
> >>  drivers/gpu/drm/Makefile                          |  1 +
> >>  drivers/gpu/drm/amd/amdgpu/Kconfig                |  1 +
> >>  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 10 +++
> >>  drivers/gpu/drm/drm_panel_backlight_quirks.c      | 94 +++++++++++++++++++++++
> >>  include/drm/drm_utils.h                           |  4 +
> >>  7 files changed, 117 insertions(+)
> >> ---
> >> base-commit: d2bafcf224f3911b183113b2fcb536c9e90684a3
> >> change-id: 20240610-amdgpu-min-backlight-quirk-8402fd8e736a
> >>
> >> Best regards,
> >> --
> >> Thomas Weißschuh <linux@weissschuh.net>
> >>
>