Re: [PATCH v3] drm/vkms: Remove index parameter from init_vkms_output

["Maíra Canal" <mcanal@igalia.com>]

On 19/11/24 10:56, Louis Chauvet wrote:
> On 19/11/24 - 14:34, Louis Chauvet wrote:
>> VKMS currently supports only one CRTC, so it make no sense to have this
>> index configurable. To avoid issues, replace this hardcoded index by
>> drm_crtc_mask when applicable.
>>
>> There is no need to manually set a crtc mask on primary and cursor plane
>> as it is automatically set by drmm_crtc_alloc_with_planes.
>>
>> In addition, this will remove the use of an uninitialized structure in
>> vkms_add_overlay_plane. This currently works by chance because two things:
>> - vkms_plane_init always set a possible_crtcs value, so the problematic
>>    branch is never used;
>> - drm_crtc_mask on an kzalloc'd drm_crtc returns BIT(0), and the VKMS CRTC
>>    always have this id.
>>
>> Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
> 
> Hi Maíra, José,
> 
> You told me "LGTM" for the v2, but without leaving a Acked/Reviewed-by,
> should I add them? Or maybe you prefer to formally send them now?

Reviewed-by: Maíra Canal <mcanal@igalia.com>

Best Regards,
- Maíra

> 
> Thanks,
> Louis Chauvet
> 
>> ---
>> Changes in v3:
>> - Rebased on drm-misc-next
>> - Link to v2: https://lore.kernel.org/r/20241010-vkms-remove-index-v2-1-6b8d6cfd5a15@bootlin.com
>>
>> Changes in v2:
>> - Applied comments from José
>> - Link to v1: https://lore.kernel.org/r/20240906-vkms-remove-index-v1-1-3cfedd8ccb2f@bootlin.com
>> ---
>>   drivers/gpu/drm/vkms/vkms_drv.c    |  2 +-
>>   drivers/gpu/drm/vkms/vkms_drv.h    |  8 ++-----
>>   drivers/gpu/drm/vkms/vkms_output.c | 49 +++++++++++++-------------------------
>>   drivers/gpu/drm/vkms/vkms_plane.c  |  4 ++--
>>   4 files changed, 21 insertions(+), 42 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/vkms/vkms_drv.c b/drivers/gpu/drm/vkms/vkms_drv.c
>> index bab13943d8e0085bed85092d7bc8727d834768a9..e4ae69d9ef871c9ce436ad0bd8c6551d8fe7f55c 100644
>> --- a/drivers/gpu/drm/vkms/vkms_drv.c
>> +++ b/drivers/gpu/drm/vkms/vkms_drv.c
>> @@ -174,7 +174,7 @@ static int vkms_modeset_init(struct vkms_device *vkmsdev)
>>   	dev->mode_config.preferred_depth = 0;
>>   	dev->mode_config.helper_private = &vkms_mode_config_helpers;
>>   
>> -	return vkms_output_init(vkmsdev, 0);
>> +	return vkms_output_init(vkmsdev);
>>   }
>>   
>>   static int vkms_create(struct vkms_config *config)
>> diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
>> index 672fe191e239c03e7358d43eb19215361417a781..036101ee4ea1cb0a335cd2ea78a8ca9da87fbe93 100644
>> --- a/drivers/gpu/drm/vkms/vkms_drv.h
>> +++ b/drivers/gpu/drm/vkms/vkms_drv.h
>> @@ -212,21 +212,17 @@ int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
>>    * vkms_output_init() - Initialize all sub-components needed for a VKMS device.
>>    *
>>    * @vkmsdev: VKMS device to initialize
>> - * @index: CRTC which can be attached to the planes. The caller must ensure that
>> - *	   @index is positive and less or equals to 31.
>>    */
>> -int vkms_output_init(struct vkms_device *vkmsdev, int index);
>> +int vkms_output_init(struct vkms_device *vkmsdev);
>>   
>>   /**
>>    * vkms_plane_init() - Initialize a plane
>>    *
>>    * @vkmsdev: VKMS device containing the plane
>>    * @type: type of plane to initialize
>> - * @index: CRTC which can be attached to the plane. The caller must ensure that
>> - *	   @index is positive and less or equals to 31.
>>    */
>>   struct vkms_plane *vkms_plane_init(struct vkms_device *vkmsdev,
>> -				   enum drm_plane_type type, int index);
>> +				   enum drm_plane_type type);
>>   
>>   /* CRC Support */
>>   const char *const *vkms_get_crc_sources(struct drm_crtc *crtc,
>> diff --git a/drivers/gpu/drm/vkms/vkms_output.c b/drivers/gpu/drm/vkms/vkms_output.c
>> index 25a99fde126c7402941954015287ab0887484139..8f4bd5aef087b459d37d0cbbf90fe0145090917a 100644
>> --- a/drivers/gpu/drm/vkms/vkms_output.c
>> +++ b/drivers/gpu/drm/vkms/vkms_output.c
>> @@ -32,29 +32,14 @@ static const struct drm_connector_helper_funcs vkms_conn_helper_funcs = {
>>   	.get_modes    = vkms_conn_get_modes,
>>   };
>>   
>> -static int vkms_add_overlay_plane(struct vkms_device *vkmsdev, int index,
>> -				  struct drm_crtc *crtc)
>> -{
>> -	struct vkms_plane *overlay;
>> -
>> -	overlay = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_OVERLAY, index);
>> -	if (IS_ERR(overlay))
>> -		return PTR_ERR(overlay);
>> -
>> -	if (!overlay->base.possible_crtcs)
>> -		overlay->base.possible_crtcs = drm_crtc_mask(crtc);
>> -
>> -	return 0;
>> -}
>> -
>> -int vkms_output_init(struct vkms_device *vkmsdev, int index)
>> +int vkms_output_init(struct vkms_device *vkmsdev)
>>   {
>>   	struct vkms_output *output = &vkmsdev->output;
>>   	struct drm_device *dev = &vkmsdev->drm;
>>   	struct drm_connector *connector = &output->connector;
>>   	struct drm_encoder *encoder = &output->encoder;
>>   	struct drm_crtc *crtc = &output->crtc;
>> -	struct vkms_plane *primary, *cursor = NULL;
>> +	struct vkms_plane *primary, *overlay, *cursor = NULL;
>>   	int ret;
>>   	int writeback;
>>   	unsigned int n;
>> @@ -65,29 +50,31 @@ int vkms_output_init(struct vkms_device *vkmsdev, int index)
>>   	 * The overlay and cursor planes are not mandatory, but can be used to perform complex
>>   	 * composition.
>>   	 */
>> -	primary = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_PRIMARY, index);
>> +	primary = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_PRIMARY);
>>   	if (IS_ERR(primary))
>>   		return PTR_ERR(primary);
>>   
>> -	if (vkmsdev->config->overlay) {
>> -		for (n = 0; n < NUM_OVERLAY_PLANES; n++) {
>> -			ret = vkms_add_overlay_plane(vkmsdev, index, crtc);
>> -			if (ret)
>> -				return ret;
>> -		}
>> -	}
>> -
>>   	if (vkmsdev->config->cursor) {
>> -		cursor = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_CURSOR, index);
>> +		cursor = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_CURSOR);
>>   		if (IS_ERR(cursor))
>>   			return PTR_ERR(cursor);
>>   	}
>>   
>> -	/* [1]: Allocation of a CRTC, its index will be BIT(0) = 1 */
>>   	ret = vkms_crtc_init(dev, crtc, &primary->base, &cursor->base);
>>   	if (ret)
>>   		return ret;
>>   
>> +	if (vkmsdev->config->overlay) {
>> +		for (n = 0; n < NUM_OVERLAY_PLANES; n++) {
>> +			overlay = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_OVERLAY);
>> +			if (IS_ERR(overlay)) {
>> +				DRM_DEV_ERROR(dev->dev, "Failed to init vkms plane\n");
>> +				return PTR_ERR(overlay);
>> +			}
>> +			overlay->base.possible_crtcs = drm_crtc_mask(crtc);
>> +		}
>> +	}
>> +
>>   	ret = drm_connector_init(dev, connector, &vkms_connector_funcs,
>>   				 DRM_MODE_CONNECTOR_VIRTUAL);
>>   	if (ret) {
>> @@ -103,11 +90,7 @@ int vkms_output_init(struct vkms_device *vkmsdev, int index)
>>   		DRM_ERROR("Failed to init encoder\n");
>>   		goto err_encoder;
>>   	}
>> -	/*
>> -	 * This is a hardcoded value to select crtc for the encoder.
>> -	 * BIT(0) here designate the first registered CRTC, the one allocated in [1]
>> -	 */
>> -	encoder->possible_crtcs = BIT(0);
>> +	encoder->possible_crtcs = drm_crtc_mask(crtc);
>>   
>>   	ret = drm_connector_attach_encoder(connector, encoder);
>>   	if (ret) {
>> diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
>> index e5c625ab8e3e06cb95f468c59bc3b06ef85eab6f..ad137c9a75f5e9ee3bb62e7bb2c5e3684a6ecbb6 100644
>> --- a/drivers/gpu/drm/vkms/vkms_plane.c
>> +++ b/drivers/gpu/drm/vkms/vkms_plane.c
>> @@ -198,12 +198,12 @@ static const struct drm_plane_helper_funcs vkms_plane_helper_funcs = {
>>   };
>>   
>>   struct vkms_plane *vkms_plane_init(struct vkms_device *vkmsdev,
>> -				   enum drm_plane_type type, int index)
>> +				   enum drm_plane_type type)
>>   {
>>   	struct drm_device *dev = &vkmsdev->drm;
>>   	struct vkms_plane *plane;
>>   
>> -	plane = drmm_universal_plane_alloc(dev, struct vkms_plane, base, 1 << index,
>> +	plane = drmm_universal_plane_alloc(dev, struct vkms_plane, base, 0,
>>   					   &vkms_plane_funcs,
>>   					   vkms_formats, ARRAY_SIZE(vkms_formats),
>>   					   NULL, type, NULL);
>>
>> ---
>> base-commit: 7d2faa8dbb7055a115fe0cd6068d7090094a573d
>> change-id: 20240906-vkms-remove-index-3a6e04c38e02
>>
>> Best regards,
>> -- 
>> Louis Chauvet <louis.chauvet@bootlin.com>
>>