Re: [PATCH v10 1/4] gpu: drm: separate panel orientation property creating and value setting

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 5/30/22 10:57, Hans de Goede wrote:
> Hi,
> 
> On 5/30/22 10:19, Hsin-Yi Wang wrote:
>> drm_dev_register() sets connector->registration_state to
>> DRM_CONNECTOR_REGISTERED and dev->registered to true. If
>> drm_connector_set_panel_orientation() is first called after
>> drm_dev_register(), it will fail several checks and results in following
>> warning.
>>
>> Add a function to create panel orientation property and set default value
>> to UNKNOWN, so drivers can call this function to init the property earlier
>> , and let the panel set the real value later.
>>
>> [    4.480976] ------------[ cut here ]------------
>> [    4.485603] WARNING: CPU: 5 PID: 369 at drivers/gpu/drm/drm_mode_object.c:45 __drm_mode_object_add+0xb4/0xbc
>> <snip>
>> [    4.609772] Call trace:
>> [    4.612208]  __drm_mode_object_add+0xb4/0xbc
>> [    4.616466]  drm_mode_object_add+0x20/0x2c
>> [    4.620552]  drm_property_create+0xdc/0x174
>> [    4.624723]  drm_property_create_enum+0x34/0x98
>> [    4.629241]  drm_connector_set_panel_orientation+0x64/0xa0
>> [    4.634716]  boe_panel_get_modes+0x88/0xd8
>> [    4.638802]  drm_panel_get_modes+0x2c/0x48
>> [    4.642887]  panel_bridge_get_modes+0x1c/0x28
>> [    4.647233]  drm_bridge_connector_get_modes+0xa0/0xd4
>> [    4.652273]  drm_helper_probe_single_connector_modes+0x218/0x700
>> [    4.658266]  drm_mode_getconnector+0x1b4/0x45c
>> [    4.662699]  drm_ioctl_kernel+0xac/0x128
>> [    4.666611]  drm_ioctl+0x268/0x410
>> [    4.670002]  drm_compat_ioctl+0xdc/0xf0
>> [    4.673829]  __arm64_compat_sys_ioctl+0xc8/0x100
>> [    4.678436]  el0_svc_common+0xf4/0x1c0
>> [    4.682174]  do_el0_svc_compat+0x28/0x3c
>> [    4.686088]  el0_svc_compat+0x10/0x1c
>> [    4.689738]  el0_sync_compat_handler+0xa8/0xcc
>> [    4.694171]  el0_sync_compat+0x178/0x180
>> [    4.698082] ---[ end trace b4f2db9d9c88610b ]---
>> [    4.702721] ------------[ cut here ]------------
>> [    4.707329] WARNING: CPU: 5 PID: 369 at drivers/gpu/drm/drm_mode_object.c:243 drm_object_attach_property+0x48/0xb8
>> <snip>
>> [    4.833830] Call trace:
>> [    4.836266]  drm_object_attach_property+0x48/0xb8
>> [    4.840958]  drm_connector_set_panel_orientation+0x84/0xa0
>> [    4.846432]  boe_panel_get_modes+0x88/0xd8
>> [    4.850516]  drm_panel_get_modes+0x2c/0x48
>> [    4.854600]  panel_bridge_get_modes+0x1c/0x28
>> [    4.858946]  drm_bridge_connector_get_modes+0xa0/0xd4
>> [    4.863984]  drm_helper_probe_single_connector_modes+0x218/0x700
>> [    4.869978]  drm_mode_getconnector+0x1b4/0x45c
>> [    4.874410]  drm_ioctl_kernel+0xac/0x128
>> [    4.878320]  drm_ioctl+0x268/0x410
>> [    4.881711]  drm_compat_ioctl+0xdc/0xf0
>> [    4.885536]  __arm64_compat_sys_ioctl+0xc8/0x100
>> [    4.890142]  el0_svc_common+0xf4/0x1c0
>> [    4.893879]  do_el0_svc_compat+0x28/0x3c
>> [    4.897791]  el0_svc_compat+0x10/0x1c
>> [    4.901441]  el0_sync_compat_handler+0xa8/0xcc
>> [    4.905873]  el0_sync_compat+0x178/0x180
>> [    4.909783] ---[ end trace b4f2db9d9c88610c ]---
>>
>> Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
>> Reviewed-by: Sean Paul <seanpaul@chromium.org>
>> ---
>> v9->v10: rebase to latest linux-next.
>> v9: https://patchwork.kernel.org/project/linux-mediatek/patch/20220318074825.3359978-2-hsinyi@chromium.org/
>> v8: https://patchwork.kernel.org/project/linux-mediatek/patch/20220208084234.1684930-1-hsinyi@chromium.org/
>> v7: https://patchwork.kernel.org/project/linux-mediatek/patch/20220208073714.1540390-1-hsinyi@chromium.org/
>> ---
>>  drivers/gpu/drm/drm_connector.c | 58 +++++++++++++++++++++++++--------
>>  include/drm/drm_connector.h     |  2 ++
>>  2 files changed, 47 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
>> index 1c48d162c77e..d68cc78f6684 100644
>> --- a/drivers/gpu/drm/drm_connector.c
>> +++ b/drivers/gpu/drm/drm_connector.c
>> @@ -1252,7 +1252,7 @@ static const struct drm_prop_enum_list dp_colorspaces[] = {
>>   *	INPUT_PROP_DIRECT) will still map 1:1 to the actual LCD panel
>>   *	coordinates, so if userspace rotates the picture to adjust for
>>   *	the orientation it must also apply the same transformation to the
>> - *	touchscreen input coordinates. This property is initialized by calling
>> + *	touchscreen input coordinates. This property value is set by calling
>>   *	drm_connector_set_panel_orientation() or
>>   *	drm_connector_set_panel_orientation_with_quirk()
>>   *
>> @@ -2310,8 +2310,8 @@ EXPORT_SYMBOL(drm_connector_set_vrr_capable_property);
>>   * @connector: connector for which to set the panel-orientation property.
>>   * @panel_orientation: drm_panel_orientation value to set
>>   *
>> - * This function sets the connector's panel_orientation and attaches
>> - * a "panel orientation" property to the connector.
>> + * This function sets the connector's panel_orientation value. If the property
>> + * doesn't exist, it will try to create one.
>>   *
>>   * Calling this function on a connector where the panel_orientation has
>>   * already been set is a no-op (e.g. the orientation has been overridden with
>> @@ -2343,18 +2343,13 @@ int drm_connector_set_panel_orientation(
>>  
>>  	prop = dev->mode_config.panel_orientation_property;
>>  	if (!prop) {
>> -		prop = drm_property_create_enum(dev, DRM_MODE_PROP_IMMUTABLE,
>> -				"panel orientation",
>> -				drm_panel_orientation_enum_list,
>> -				ARRAY_SIZE(drm_panel_orientation_enum_list));
>> -		if (!prop)
>> +		if (drm_connector_init_panel_orientation_property(connector) < 0)
>>  			return -ENOMEM;
>> -
>> -		dev->mode_config.panel_orientation_property = prop;
>> +		prop = dev->mode_config.panel_orientation_property;
>>  	}
>>  
>> -	drm_object_attach_property(&connector->base, prop,
>> -				   info->panel_orientation);
>> +	drm_object_property_set_value(&connector->base, prop,
>> +				      info->panel_orientation);
>>  	return 0;
>>  }
>>  EXPORT_SYMBOL(drm_connector_set_panel_orientation);
>> @@ -2362,7 +2357,7 @@ EXPORT_SYMBOL(drm_connector_set_panel_orientation);
>>  /**
>>   * drm_connector_set_panel_orientation_with_quirk - set the
>>   *	connector's panel_orientation after checking for quirks
>> - * @connector: connector for which to init the panel-orientation property.
>> + * @connector: connector for which to set the panel-orientation property.
>>   * @panel_orientation: drm_panel_orientation value to set
>>   * @width: width in pixels of the panel, used for panel quirk detection
>>   * @height: height in pixels of the panel, used for panel quirk detection
>> @@ -2389,6 +2384,43 @@ int drm_connector_set_panel_orientation_with_quirk(
>>  }
>>  EXPORT_SYMBOL(drm_connector_set_panel_orientation_with_quirk);
>>  
>> +/**
>> + * drm_connector_init_panel_orientation_property -
>> + * 	create the connector's panel orientation property
>> + *
>> + * This function attaches a "panel orientation" property to the connector
>> + * and initializes its value to DRM_MODE_PANEL_ORIENTATION_UNKNOWN.
>> + *
>> + * The value of the property can be set by drm_connector_set_panel_orientation()
>> + * or drm_connector_set_panel_orientation_with_quirk() later.
>> + *
>> + * Returns:
>> + * Zero on success, negative errno on failure.
>> + */
>> +int drm_connector_init_panel_orientation_property(
>> +	struct drm_connector *connector)
>> +{
>> +	struct drm_device *dev = connector->dev;
>> +	struct drm_property *prop;
>> +
>> +	if(dev->mode_config.panel_orientation_property)
>> +		return 0;
>> +
>> +	prop = drm_property_create_enum(dev, DRM_MODE_PROP_IMMUTABLE,
>> +			"panel orientation",
>> +			drm_panel_orientation_enum_list,
>> +			ARRAY_SIZE(drm_panel_orientation_enum_list));
>> +	if (!prop)
>> +		return -ENOMEM;
>> +
>> +	dev->mode_config.panel_orientation_property = prop;
>> +	drm_object_attach_property(&connector->base, prop,
>> +				   DRM_MODE_PANEL_ORIENTATION_UNKNOWN);
> 
> DRM_MODE_PANEL_ORIENTATION_UNKNOWN is -1 which is not a valid value
> for an enum. IOW when the panel-orientation is DRM_MODE_PANEL_ORIENTATION_UNKNOWN
> then the property should not be created on the drm-connector object at all.

p.s. note that the original drm_connector_set_panel_orientation() avoids
ever creating the property when the orientation is unknown because of
this bit of code near the top of the function:

        /* Don't attach the property if the orientation is unknown */
        if (panel_orientation == DRM_MODE_PANEL_ORIENTATION_UNKNOWN)
                return 0;

> Which brings us back to what I said in reply to the coverletter,
> it seems that you have a probe ordering problem here; and fixing that
> issue would make this patch-set unnecessary.

Regards,

Hans


>> +
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL(drm_connector_init_panel_orientation_property);
>> +
>>  static const struct drm_prop_enum_list privacy_screen_enum[] = {
>>  	{ PRIVACY_SCREEN_DISABLED,		"Disabled" },
>>  	{ PRIVACY_SCREEN_ENABLED,		"Enabled" },
>> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
>> index 3ac4bf87f257..f0681091c617 100644
>> --- a/include/drm/drm_connector.h
>> +++ b/include/drm/drm_connector.h
>> @@ -1802,6 +1802,8 @@ int drm_connector_set_panel_orientation_with_quirk(
>>  	struct drm_connector *connector,
>>  	enum drm_panel_orientation panel_orientation,
>>  	int width, int height);
>> +int drm_connector_init_panel_orientation_property(
>> +	struct drm_connector *connector);
>>  int drm_connector_attach_max_bpc_property(struct drm_connector *connector,
>>  					  int min, int max);
>>  void drm_connector_create_privacy_screen_properties(struct drm_connector *conn);