Re: [PATCH] drm/amd/display: add panel_power_savings sysfs entry to eDP connectors

[Dominik Förderer]

I've applied the patch to 6.7.2. The device then shows up under:

/sys/devices/pci0000:00/0000:00:08.1/0000:c1:00.0/drm/card1/card1-eDP-1/amdgpu/panel_power_savings
(on Framework Laptop 13 amd 7840U with 780M).



Setting an abmlevel via kernel option still works as intended.








Am 26.01.24 um 23:22 schrieb Hamza Mahfooz:

After a few tests i can say that at least in my system it’s not working. Setting a value between 0 and 4 in /sys/.../panel_power_savings changes nothing in the panel behavior. There are no errors in kernel log. The issue can be resolved if one set the panel_power_savings value and after that change the display resolution to a lower value and than switch back. For example this script works: xterm -e 'echo 0 | sudo tee /sys/devices/pci0000:00/0000:00:08.1/0000:c1:00.0/drm/card1/card1-eDP-1/amdgpu/panel_power_savings' gnome-randr modify -m 1920x1200@59.999 eDP-1 && gnome-randr modify -m 2256x1504@59.999 eDP-1

We want programs besides the compositor to be able to enable or disable
panel power saving features. However, since they are currently only
configurable through DRM properties, that isn't possible. So, to remedy
that issue introduce a new "panel_power_savings" sysfs attribute.

Cc: Mario Limonciello <mario.limoncie...@amd.com>
Signed-off-by: Hamza Mahfooz <hamza.mahf...@amd.com>
---
.../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 59 +++++++++++++++++++
1 file changed, 59 insertions(+)


index cd98b3565178..b3fcd833015d 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

return &new_state->base;
}
+static ssize_t panel_power_savings_show(struct device *device,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct drm_connector *connector = dev_get_drvdata(device);
+ struct drm_device *dev = connector->dev;
+ ssize_t val;
+
+ drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
+ val = to_dm_connector_state(connector->state)->abm_level;
+ drm_modeset_unlock(&dev->mode_config.connection_mutex);
+
+ return sysfs_emit(buf, "%lu\n", val);
+}
+
+static ssize_t panel_power_savings_store(struct device *device,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct drm_connector *connector = dev_get_drvdata(device);
+ struct drm_device *dev = connector->dev;
+ long val;
+ int ret;
+
+ ret = kstrtol(buf, 0, &val);
+
+ if (ret)
+ return ret;
+
+ if (val < 0 || val > 4)
+ return -EINVAL;
+
+ drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
+ to_dm_connector_state(connector->state)->abm_level = val ?:
+ ABM_LEVEL_IMMEDIATE_DISABLE;
+ drm_modeset_unlock(&dev->mode_config.connection_mutex);
+
+ return count;
+}
+
+static DEVICE_ATTR_RW(panel_power_savings);
+
+static struct attribute *amdgpu_attrs[] = {
+ &dev_attr_panel_power_savings.attr,
+ NULL
+};
+
+static const struct attribute_group amdgpu_group = {
+ .name = "amdgpu",
+ .attrs = amdgpu_attrs
+};
+
static int
amdgpu_dm_connector_late_register(struct drm_connector *connector)
{

to_amdgpu_dm_connector(connector);
int r;
+ if (connector->connector_type == DRM_MODE_CONNECTOR_eDP) {
+ r = sysfs_create_group(&connector->kdev->kobj,
+ &amdgpu_group);
+ if (r)
+ return r;
+ }
+
amdgpu_dm_register_backlight_device(amdgpu_dm_connector);
if ((connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort) ||

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -6534,6 +6534,58 @@ amdgpu_dm_connector_atomic_duplicate_state(struct drm_connector *connector) @@ -6541,6 +6593,13 @@ amdgpu_dm_connector_late_register(struct drm_connector *connector)

--
Dominik Förderer (Netzwerkadministrator)
Windeck-Gymnasium Bühl
Humboldtstr. 3
Tel. 07223/9409585

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