| Message ID | 20240814-google-clarifications-v1-3-3ee76d7d0c28@bootlin.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/vkms: Miscelanious clarifications | expand |
Hi Louis, I'd make this patch more incremental. First, send me a patch based on drm-misc-next with the new documentation for the things that already exists. Then, when you add a new field, you add the documentation with it. On 8/14/24 05:47, Louis Chauvet wrote: > Add documentation around vkms_output and its initialization. > > Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com> > --- > drivers/gpu/drm/vkms/vkms_drv.h | 81 ++++++++++++++++++++++++++++++++------ > drivers/gpu/drm/vkms/vkms_output.c | 12 +++++- > 2 files changed, 80 insertions(+), 13 deletions(-) > > diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h > index 3028678e4f9b..8f6c9e67e671 100644 > --- a/drivers/gpu/drm/vkms/vkms_drv.h > +++ b/drivers/gpu/drm/vkms/vkms_drv.h > @@ -147,29 +147,51 @@ struct vkms_color_lut { > }; > > /** > - * vkms_crtc_state - Driver specific CRTC state > + * struct vkms_crtc_state - Driver specific CRTC state > + * > * @base: base CRTC state > * @composer_work: work struct to compose and add CRC entries > - * @n_frame_start: start frame number for computed CRC > - * @n_frame_end: end frame number for computed CRC > + * > + * @num_active_planes: Number of active planes > + * @active_planes: List containing all the active planes (counted by > + * @num_active_planes). They should be stored in z-order. > + * @active_writeback: Current active writeback job > + * @gamma_lut: Look up table for gamma used in this CRTC > + * @crc_pending: Protected by @vkms_output.composer_lock. > + * @wb_pending: Protected by @vkms_output.composer_lock. > + * @frame_start: Protected by @vkms_output.composer_lock. > + * @frame_end: Protected by @vkms_output.composer_lock. Apart from being protected by @vkms_output.composer_lock, what those variables represent? > */ > struct vkms_crtc_state { > struct drm_crtc_state base; > struct work_struct composer_work; > > int num_active_planes; > - /* stack of active planes for crc computation, should be in z order */ > struct vkms_plane_state **active_planes; > struct vkms_writeback_job *active_writeback; > struct vkms_color_lut gamma_lut; > > - /* below four are protected by vkms_output.composer_lock */ > bool crc_pending; > bool wb_pending; > u64 frame_start; > u64 frame_end; > }; > > +/** > + * struct vkms_output - Internal representation of all output components in vkms > + * > + * @crtc: Base crtc in drm s/crtc/CRTC and s/drm/DRM > + * @encoder: DRM encoder used for this output > + * @connector: DRM connector used for this output > + * @wb_connecter: DRM writeback connector used for this output > + * @vblank_hrtimer: > + * @period_ns: Empty? > + * @composer_workq: Ordered workqueue for composer_work Add reference to composer_work > + * @lock: Lock used to project concurrent acces to the composer s/acces/access > + * @composer_enabled: Protected by @lock. > + * @composer_state: Empty? > + * @composer_lock: Lock used internally to protect @composer_state members > + */ > struct vkms_output { > struct drm_crtc crtc; > struct drm_encoder encoder; > @@ -177,28 +199,38 @@ struct vkms_output { > struct drm_writeback_connector wb_connector; > struct hrtimer vblank_hrtimer; > ktime_t period_ns; > - /* ordered wq for composer_work */ > struct workqueue_struct *composer_workq; > - /* protects concurrent access to composer */ > spinlock_t lock; > > - /* protected by @lock */ > bool composer_enabled; > struct vkms_crtc_state *composer_state; > > spinlock_t composer_lock; > }; > > -struct vkms_device; > - > +/** > + * struct vkms_config - General configuration for VKMS driver > + * > + * @writeback: If true, a writeback buffer can be attached to the CRTC > + * @cursor: If true, a cursor plane is created in the VKMS device > + * @overlay: If true, NUM_OVERLAY_PLANES will be created for the VKMS device > + * @dev: Used to store the current vkms device. Only set when the device is instancied. s/instancied/instantiated > + */ > struct vkms_config { > bool writeback; > bool cursor; > bool overlay; > - /* only set when instantiated */ > struct vkms_device *dev; > }; > > +/** > + * struct vkms_device - Description of a vkms device > + * > + * @drm - Base device in drm s/drm/DRM > + * @platform - Associated platform device > + * @output - Configuration and sub-components of the vkms device > + * @config: Configuration used in this vkms device > + */ > struct vkms_device { > struct drm_device drm; > struct platform_device *platform; > @@ -206,6 +238,10 @@ struct vkms_device { > const struct vkms_config *config; > }; > > +/* > + * The following helpers are used to convert a member of a struct into its parent. > + */ > + > #define drm_crtc_to_vkms_output(target) \ > container_of(target, struct vkms_output, crtc) > > @@ -218,12 +254,33 @@ struct vkms_device { > #define to_vkms_plane_state(target)\ > container_of(target, struct vkms_plane_state, base.base) > > -/* CRTC */ > +/** > + * vkms_crtc_init() - Initialize a crtc for vkms > + * @dev: drm_device associated with the vkms buffer DRM device > + * @crtc: uninitialized crtc device > + * @primary: primary plane to attach to the crtc > + * @cursor plane to attach to the crtc s/crtc/CRTC everywhere > + */ New line > int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc, > struct drm_plane *primary, struct drm_plane *cursor); > +/** > + * vkms_output_init() - Initialize all sub-components needed for a vkms device. > + * > + * @vkmsdev: vkms device to initialize > + * @possible_crtc_index: Crtc which can be attached to the planes. The caller must ensure that > + * possible_crtc_index is positive and less or equals to 31. > + */ > Delete line > int vkms_output_init(struct vkms_device *vkmsdev, int possible_crtc_index); > > +/** > + * vkms_plane_init() - Initialize a plane > + * > + * @vkmsdev: vkms device containing the plane > + * @type: type of plane to initialize > + * @possible_crtc_index: Crtc which can be attached to the plane. The caller must ensure that s/crtc/CRTC everywhere > + * possible_crtc_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 possible_crtc_index); > > diff --git a/drivers/gpu/drm/vkms/vkms_output.c b/drivers/gpu/drm/vkms/vkms_output.c > index d42ca7d10389..36db2c8923cb 100644 > --- a/drivers/gpu/drm/vkms/vkms_output.c > +++ b/drivers/gpu/drm/vkms/vkms_output.c > @@ -21,6 +21,7 @@ static int vkms_conn_get_modes(struct drm_connector *connector) > { > int count; > > + /* Use the default modes list from drm */ s/drm/DRM > count = drm_add_modes_noedid(connector, XRES_MAX, YRES_MAX); > drm_set_preferred_mode(connector, XRES_DEF, YRES_DEF); > > @@ -58,8 +59,13 @@ int vkms_output_init(struct vkms_device *vkmsdev, int possible_crtc_index) > int writeback; > unsigned int n; > > + /* > + * Initialize used plane. One primary plane is required to perform the composition. > + * > + * 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, possible_crtc_index); > - > if (IS_ERR(primary)) > return PTR_ERR(primary); > > @@ -96,6 +102,10 @@ int vkms_output_init(struct vkms_device *vkmsdev, int possible_crtc_index) > DRM_ERROR("Failed to init encoder\n"); > goto err_encoder; > } > + /* > + * This is an hardcoded value to select crtc for the encoder. > + * 1 here designate the first registered CRTC, the one allocated in [1] Where is [1]? Best Regards, - Maíra > + */ > encoder->possible_crtcs = 1; > > ret = drm_connector_attach_encoder(connector, encoder); >
Hi Louis, Thanks for this patch, adding some minor review comments: > Add documentation around vkms_output and its initialization. > > Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com> > --- > drivers/gpu/drm/vkms/vkms_drv.h | 81 ++++++++++++++++++++++++++++++++------ > drivers/gpu/drm/vkms/vkms_output.c | 12 +++++- > 2 files changed, 80 insertions(+), 13 deletions(-) > > diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h > index 3028678e4f9b..8f6c9e67e671 100644 > --- a/drivers/gpu/drm/vkms/vkms_drv.h > +++ b/drivers/gpu/drm/vkms/vkms_drv.h > @@ -147,29 +147,51 @@ struct vkms_color_lut { > }; > > /** > - * vkms_crtc_state - Driver specific CRTC state > + * struct vkms_crtc_state - Driver specific CRTC state Not in this line, but around line 55, the documentation for vkms_plane_state is missing the "struct" keyword: - * vkms_plane_state - Driver specific plane state + * struct vkms_plane_state - Driver specific plane state I'd be nice to add it since we are improving the documentation. > + * > * @base: base CRTC state > * @composer_work: work struct to compose and add CRC entries > - * @n_frame_start: start frame number for computed CRC > - * @n_frame_end: end frame number for computed CRC > + * > + * @num_active_planes: Number of active planes > + * @active_planes: List containing all the active planes (counted by > + * @num_active_planes). They should be stored in z-order. > + * @active_writeback: Current active writeback job > + * @gamma_lut: Look up table for gamma used in this CRTC > + * @crc_pending: Protected by @vkms_output.composer_lock. > + * @wb_pending: Protected by @vkms_output.composer_lock. > + * @frame_start: Protected by @vkms_output.composer_lock. > + * @frame_end: Protected by @vkms_output.composer_lock. > */ > struct vkms_crtc_state { > struct drm_crtc_state base; > struct work_struct composer_work; > > int num_active_planes; > - /* stack of active planes for crc computation, should be in z order */ > struct vkms_plane_state **active_planes; > struct vkms_writeback_job *active_writeback; > struct vkms_color_lut gamma_lut; > > - /* below four are protected by vkms_output.composer_lock */ > bool crc_pending; > bool wb_pending; > u64 frame_start; > u64 frame_end; > }; > > +/** > + * struct vkms_output - Internal representation of all output components in vkms I think that VKMS is usually spelled in capital letters in other places. > + * > + * @crtc: Base crtc in drm > + * @encoder: DRM encoder used for this output > + * @connector: DRM connector used for this output > + * @wb_connecter: DRM writeback connector used for this output > + * @vblank_hrtimer: > + * @period_ns: My suggestion when reviewing a previous version of this patch in your GitHub fork was: @vblank_hrtimer: Timer used to simulate vblank events @period_ns: vblank period, in nanoseconds > + * @composer_workq: Ordered workqueue for composer_work > + * @lock: Lock used to project concurrent acces to the composer > + * @composer_enabled: Protected by @lock. > + * @composer_state: I think that @composer_state is "Protected by @lock" as well. > + * @composer_lock: Lock used internally to protect @composer_state members > + */ > struct vkms_output { > struct drm_crtc crtc; > struct drm_encoder encoder; > @@ -177,28 +199,38 @@ struct vkms_output { > struct drm_writeback_connector wb_connector; > struct hrtimer vblank_hrtimer; > ktime_t period_ns; > - /* ordered wq for composer_work */ > struct workqueue_struct *composer_workq; > - /* protects concurrent access to composer */ > spinlock_t lock; > > - /* protected by @lock */ > bool composer_enabled; > struct vkms_crtc_state *composer_state; > > spinlock_t composer_lock; > }; > > -struct vkms_device; > - > +/** > + * struct vkms_config - General configuration for VKMS driver > + * > + * @writeback: If true, a writeback buffer can be attached to the CRTC > + * @cursor: If true, a cursor plane is created in the VKMS device > + * @overlay: If true, NUM_OVERLAY_PLANES will be created for the VKMS device > + * @dev: Used to store the current vkms device. Only set when the device is instancied. s/vkms/VKMS and s/instancied/instantiated > + */ > struct vkms_config { > bool writeback; > bool cursor; > bool overlay; > - /* only set when instantiated */ > struct vkms_device *dev; > }; > > +/** > + * struct vkms_device - Description of a vkms device s/vkms/VKMS > + * > + * @drm - Base device in drm > + * @platform - Associated platform device > + * @output - Configuration and sub-components of the vkms device s/vkms/VKMS > + * @config: Configuration used in this vkms device s/vkms/VKMS > + */ > struct vkms_device { > struct drm_device drm; > struct platform_device *platform; > @@ -206,6 +238,10 @@ struct vkms_device { > const struct vkms_config *config; > }; > > +/* > + * The following helpers are used to convert a member of a struct into its parent. > + */ > + > #define drm_crtc_to_vkms_output(target) \ > container_of(target, struct vkms_output, crtc) > > @@ -218,12 +254,33 @@ struct vkms_device { > #define to_vkms_plane_state(target)\ > container_of(target, struct vkms_plane_state, base.base) > > -/* CRTC */ > +/** > + * vkms_crtc_init() - Initialize a crtc for vkms s/vkms/VKMS > + * @dev: drm_device associated with the vkms buffer s/vkms/VKMS > + * @crtc: uninitialized crtc device > + * @primary: primary plane to attach to the crtc > + * @cursor plane to attach to the crtc > + */ > int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc, > struct drm_plane *primary, struct drm_plane *cursor); > +/** > + * vkms_output_init() - Initialize all sub-components needed for a vkms device. s/vkms/VKMS > + * > + * @vkmsdev: vkms device to initialize s/vkms/VKMS > + * @possible_crtc_index: Crtc which can be attached to the planes. The caller must ensure that > + * possible_crtc_index is positive and less or equals to 31. Missing "@". Also, since the second patch of this series won't be applied, remember to rename the documentation to "@index". > + */ > > int vkms_output_init(struct vkms_device *vkmsdev, int possible_crtc_index); > > +/** > + * vkms_plane_init() - Initialize a plane > + * > + * @vkmsdev: vkms device containing the plane s/vkms/VKMS > + * @type: type of plane to initialize > + * @possible_crtc_index: Crtc which can be attached to the plane. The caller must ensure that > + * possible_crtc_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 possible_crtc_index); > > diff --git a/drivers/gpu/drm/vkms/vkms_output.c b/drivers/gpu/drm/vkms/vkms_output.c > index d42ca7d10389..36db2c8923cb 100644 > --- a/drivers/gpu/drm/vkms/vkms_output.c > +++ b/drivers/gpu/drm/vkms/vkms_output.c > @@ -21,6 +21,7 @@ static int vkms_conn_get_modes(struct drm_connector *connector) > { > int count; > > + /* Use the default modes list from drm */ > count = drm_add_modes_noedid(connector, XRES_MAX, YRES_MAX); > drm_set_preferred_mode(connector, XRES_DEF, YRES_DEF); > > @@ -58,8 +59,13 @@ int vkms_output_init(struct vkms_device *vkmsdev, int possible_crtc_index) > int writeback; > unsigned int n; > > + /* > + * Initialize used plane. One primary plane is required to perform the composition. > + * > + * 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, possible_crtc_index); > - > if (IS_ERR(primary)) > return PTR_ERR(primary); > > @@ -96,6 +102,10 @@ int vkms_output_init(struct vkms_device *vkmsdev, int possible_crtc_index) > DRM_ERROR("Failed to init encoder\n"); > goto err_encoder; > } > + /* > + * This is an hardcoded value to select crtc for the encoder. s/an/a > + * 1 here designate the first registered CRTC, the one allocated in [1] > + */ I think that replacing "= 1;" with "= BIT(0);" might help to understand that possible_crtcs is a bitmask and also that CRTC 0 is used by default. We might even be able to drop the comment... Even though this will change with our configfs changes quite a lot. > encoder->possible_crtcs = 1; > > ret = drm_connector_attach_encoder(connector, encoder);
Le 19/08/24 - 17:07, José Expósito a écrit : > Hi Louis, > > Thanks for this patch, adding some minor review comments: > > > Add documentation around vkms_output and its initialization. > > > > Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com> > > --- > > drivers/gpu/drm/vkms/vkms_drv.h | 81 ++++++++++++++++++++++++++++++++------ > > drivers/gpu/drm/vkms/vkms_output.c | 12 +++++- > > 2 files changed, 80 insertions(+), 13 deletions(-) > > > > diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h > > index 3028678e4f9b..8f6c9e67e671 100644 > > --- a/drivers/gpu/drm/vkms/vkms_drv.h > > +++ b/drivers/gpu/drm/vkms/vkms_drv.h > > @@ -147,29 +147,51 @@ struct vkms_color_lut { > > }; > > > > /** > > - * vkms_crtc_state - Driver specific CRTC state > > + * struct vkms_crtc_state - Driver specific CRTC state > > Not in this line, but around line 55, the documentation for vkms_plane_state > is missing the "struct" keyword: This is fixed by [1], but I can move this patch here. [1]: https://lore.kernel.org/all/20240802-yuv-v9-3-08a706669e16@bootlin.com/ > - * vkms_plane_state - Driver specific plane state > + * struct vkms_plane_state - Driver specific plane state > > I'd be nice to add it since we are improving the documentation. > > > + * > > * @base: base CRTC state > > * @composer_work: work struct to compose and add CRC entries > > - * @n_frame_start: start frame number for computed CRC > > - * @n_frame_end: end frame number for computed CRC > > + * > > + * @num_active_planes: Number of active planes > > + * @active_planes: List containing all the active planes (counted by > > + * @num_active_planes). They should be stored in z-order. > > + * @active_writeback: Current active writeback job > > + * @gamma_lut: Look up table for gamma used in this CRTC > > + * @crc_pending: Protected by @vkms_output.composer_lock. > > + * @wb_pending: Protected by @vkms_output.composer_lock. > > + * @frame_start: Protected by @vkms_output.composer_lock. > > + * @frame_end: Protected by @vkms_output.composer_lock. > > */ > > struct vkms_crtc_state { > > struct drm_crtc_state base; > > struct work_struct composer_work; > > > > int num_active_planes; > > - /* stack of active planes for crc computation, should be in z order */ > > struct vkms_plane_state **active_planes; > > struct vkms_writeback_job *active_writeback; > > struct vkms_color_lut gamma_lut; > > > > - /* below four are protected by vkms_output.composer_lock */ > > bool crc_pending; > > bool wb_pending; > > u64 frame_start; > > u64 frame_end; > > }; > > > > +/** > > + * struct vkms_output - Internal representation of all output components in vkms > > I think that VKMS is usually spelled in capital letters in other places. > > > + * > > + * @crtc: Base crtc in drm > > + * @encoder: DRM encoder used for this output > > + * @connector: DRM connector used for this output > > + * @wb_connecter: DRM writeback connector used for this output > > + * @vblank_hrtimer: > > + * @period_ns: > > My suggestion when reviewing a previous version of this patch in your > GitHub fork was: > > @vblank_hrtimer: Timer used to simulate vblank events > @period_ns: vblank period, in nanoseconds > > > + * @composer_workq: Ordered workqueue for composer_work > > + * @lock: Lock used to project concurrent acces to the composer > > + * @composer_enabled: Protected by @lock. > > + * @composer_state: > > I think that @composer_state is "Protected by @lock" as well. > > > + * @composer_lock: Lock used internally to protect @composer_state members > > + */ > > struct vkms_output { > > struct drm_crtc crtc; > > struct drm_encoder encoder; > > @@ -177,28 +199,38 @@ struct vkms_output { > > struct drm_writeback_connector wb_connector; > > struct hrtimer vblank_hrtimer; > > ktime_t period_ns; > > - /* ordered wq for composer_work */ > > struct workqueue_struct *composer_workq; > > - /* protects concurrent access to composer */ > > spinlock_t lock; > > > > - /* protected by @lock */ > > bool composer_enabled; > > struct vkms_crtc_state *composer_state; > > > > spinlock_t composer_lock; > > }; > > > > -struct vkms_device; > > - > > +/** > > + * struct vkms_config - General configuration for VKMS driver > > + * > > + * @writeback: If true, a writeback buffer can be attached to the CRTC > > + * @cursor: If true, a cursor plane is created in the VKMS device > > + * @overlay: If true, NUM_OVERLAY_PLANES will be created for the VKMS device > > + * @dev: Used to store the current vkms device. Only set when the device is instancied. > > s/vkms/VKMS and s/instancied/instantiated > > > + */ > > struct vkms_config { > > bool writeback; > > bool cursor; > > bool overlay; > > - /* only set when instantiated */ > > struct vkms_device *dev; > > }; > > > > +/** > > + * struct vkms_device - Description of a vkms device > > s/vkms/VKMS > > > + * > > + * @drm - Base device in drm > > + * @platform - Associated platform device > > + * @output - Configuration and sub-components of the vkms device > > s/vkms/VKMS > > > + * @config: Configuration used in this vkms device > > s/vkms/VKMS > > > + */ > > struct vkms_device { > > struct drm_device drm; > > struct platform_device *platform; > > @@ -206,6 +238,10 @@ struct vkms_device { > > const struct vkms_config *config; > > }; > > > > +/* > > + * The following helpers are used to convert a member of a struct into its parent. > > + */ > > + > > #define drm_crtc_to_vkms_output(target) \ > > container_of(target, struct vkms_output, crtc) > > > > @@ -218,12 +254,33 @@ struct vkms_device { > > #define to_vkms_plane_state(target)\ > > container_of(target, struct vkms_plane_state, base.base) > > > > -/* CRTC */ > > +/** > > + * vkms_crtc_init() - Initialize a crtc for vkms > > s/vkms/VKMS > > > + * @dev: drm_device associated with the vkms buffer > > s/vkms/VKMS > > > + * @crtc: uninitialized crtc device > > + * @primary: primary plane to attach to the crtc > > + * @cursor plane to attach to the crtc > > + */ > > int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc, > > struct drm_plane *primary, struct drm_plane *cursor); > > +/** > > + * vkms_output_init() - Initialize all sub-components needed for a vkms device. > > s/vkms/VKMS > > > + * > > + * @vkmsdev: vkms device to initialize > > s/vkms/VKMS > > > + * @possible_crtc_index: Crtc which can be attached to the planes. The caller must ensure that > > + * possible_crtc_index is positive and less or equals to 31. > > Missing "@". Also, since the second patch of this series won't be applied, > remember to rename the documentation to "@index". > > + */ > > > > int vkms_output_init(struct vkms_device *vkmsdev, int possible_crtc_index); > > > > +/** > > + * vkms_plane_init() - Initialize a plane > > + * > > + * @vkmsdev: vkms device containing the plane > > s/vkms/VKMS > > > + * @type: type of plane to initialize > > + * @possible_crtc_index: Crtc which can be attached to the plane. The caller must ensure that > > + * possible_crtc_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 possible_crtc_index); > > > > diff --git a/drivers/gpu/drm/vkms/vkms_output.c b/drivers/gpu/drm/vkms/vkms_output.c > > index d42ca7d10389..36db2c8923cb 100644 > > --- a/drivers/gpu/drm/vkms/vkms_output.c > > +++ b/drivers/gpu/drm/vkms/vkms_output.c > > @@ -21,6 +21,7 @@ static int vkms_conn_get_modes(struct drm_connector *connector) > > { > > int count; > > > > + /* Use the default modes list from drm */ > > count = drm_add_modes_noedid(connector, XRES_MAX, YRES_MAX); > > drm_set_preferred_mode(connector, XRES_DEF, YRES_DEF); > > > > @@ -58,8 +59,13 @@ int vkms_output_init(struct vkms_device *vkmsdev, int possible_crtc_index) > > int writeback; > > unsigned int n; > > > > + /* > > + * Initialize used plane. One primary plane is required to perform the composition. > > + * > > + * 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, possible_crtc_index); > > - > > if (IS_ERR(primary)) > > return PTR_ERR(primary); > > > > @@ -96,6 +102,10 @@ int vkms_output_init(struct vkms_device *vkmsdev, int possible_crtc_index) > > DRM_ERROR("Failed to init encoder\n"); > > goto err_encoder; > > } > > + /* > > + * This is an hardcoded value to select crtc for the encoder. > > s/an/a > > > + * 1 here designate the first registered CRTC, the one allocated in [1] > > + */ > > I think that replacing "= 1;" with "= BIT(0);" might help to understand > that possible_crtcs is a bitmask and also that CRTC 0 is used by default. > We might even be able to drop the comment... Even though this will change > with our configfs changes quite a lot. This comment was mainly for me to understand why there is this =1. I will change it to =BIT(0) for clarity, but keep the comment as it is not obvious why this value is hardcoded. > > encoder->possible_crtcs = 1; > > > > ret = drm_connector_attach_encoder(connector, encoder);
diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h index 3028678e4f9b..8f6c9e67e671 100644 --- a/drivers/gpu/drm/vkms/vkms_drv.h +++ b/drivers/gpu/drm/vkms/vkms_drv.h @@ -147,29 +147,51 @@ struct vkms_color_lut { }; /** - * vkms_crtc_state - Driver specific CRTC state + * struct vkms_crtc_state - Driver specific CRTC state + * * @base: base CRTC state * @composer_work: work struct to compose and add CRC entries - * @n_frame_start: start frame number for computed CRC - * @n_frame_end: end frame number for computed CRC + * + * @num_active_planes: Number of active planes + * @active_planes: List containing all the active planes (counted by + * @num_active_planes). They should be stored in z-order. + * @active_writeback: Current active writeback job + * @gamma_lut: Look up table for gamma used in this CRTC + * @crc_pending: Protected by @vkms_output.composer_lock. + * @wb_pending: Protected by @vkms_output.composer_lock. + * @frame_start: Protected by @vkms_output.composer_lock. + * @frame_end: Protected by @vkms_output.composer_lock. */ struct vkms_crtc_state { struct drm_crtc_state base; struct work_struct composer_work; int num_active_planes; - /* stack of active planes for crc computation, should be in z order */ struct vkms_plane_state **active_planes; struct vkms_writeback_job *active_writeback; struct vkms_color_lut gamma_lut; - /* below four are protected by vkms_output.composer_lock */ bool crc_pending; bool wb_pending; u64 frame_start; u64 frame_end; }; +/** + * struct vkms_output - Internal representation of all output components in vkms + * + * @crtc: Base crtc in drm + * @encoder: DRM encoder used for this output + * @connector: DRM connector used for this output + * @wb_connecter: DRM writeback connector used for this output + * @vblank_hrtimer: + * @period_ns: + * @composer_workq: Ordered workqueue for composer_work + * @lock: Lock used to project concurrent acces to the composer + * @composer_enabled: Protected by @lock. + * @composer_state: + * @composer_lock: Lock used internally to protect @composer_state members + */ struct vkms_output { struct drm_crtc crtc; struct drm_encoder encoder; @@ -177,28 +199,38 @@ struct vkms_output { struct drm_writeback_connector wb_connector; struct hrtimer vblank_hrtimer; ktime_t period_ns; - /* ordered wq for composer_work */ struct workqueue_struct *composer_workq; - /* protects concurrent access to composer */ spinlock_t lock; - /* protected by @lock */ bool composer_enabled; struct vkms_crtc_state *composer_state; spinlock_t composer_lock; }; -struct vkms_device; - +/** + * struct vkms_config - General configuration for VKMS driver + * + * @writeback: If true, a writeback buffer can be attached to the CRTC + * @cursor: If true, a cursor plane is created in the VKMS device + * @overlay: If true, NUM_OVERLAY_PLANES will be created for the VKMS device + * @dev: Used to store the current vkms device. Only set when the device is instancied. + */ struct vkms_config { bool writeback; bool cursor; bool overlay; - /* only set when instantiated */ struct vkms_device *dev; }; +/** + * struct vkms_device - Description of a vkms device + * + * @drm - Base device in drm + * @platform - Associated platform device + * @output - Configuration and sub-components of the vkms device + * @config: Configuration used in this vkms device + */ struct vkms_device { struct drm_device drm; struct platform_device *platform; @@ -206,6 +238,10 @@ struct vkms_device { const struct vkms_config *config; }; +/* + * The following helpers are used to convert a member of a struct into its parent. + */ + #define drm_crtc_to_vkms_output(target) \ container_of(target, struct vkms_output, crtc) @@ -218,12 +254,33 @@ struct vkms_device { #define to_vkms_plane_state(target)\ container_of(target, struct vkms_plane_state, base.base) -/* CRTC */ +/** + * vkms_crtc_init() - Initialize a crtc for vkms + * @dev: drm_device associated with the vkms buffer + * @crtc: uninitialized crtc device + * @primary: primary plane to attach to the crtc + * @cursor plane to attach to the crtc + */ int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc, struct drm_plane *primary, struct drm_plane *cursor); +/** + * vkms_output_init() - Initialize all sub-components needed for a vkms device. + * + * @vkmsdev: vkms device to initialize + * @possible_crtc_index: Crtc which can be attached to the planes. The caller must ensure that + * possible_crtc_index is positive and less or equals to 31. + */ int vkms_output_init(struct vkms_device *vkmsdev, int possible_crtc_index); +/** + * vkms_plane_init() - Initialize a plane + * + * @vkmsdev: vkms device containing the plane + * @type: type of plane to initialize + * @possible_crtc_index: Crtc which can be attached to the plane. The caller must ensure that + * possible_crtc_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 possible_crtc_index); diff --git a/drivers/gpu/drm/vkms/vkms_output.c b/drivers/gpu/drm/vkms/vkms_output.c index d42ca7d10389..36db2c8923cb 100644 --- a/drivers/gpu/drm/vkms/vkms_output.c +++ b/drivers/gpu/drm/vkms/vkms_output.c @@ -21,6 +21,7 @@ static int vkms_conn_get_modes(struct drm_connector *connector) { int count; + /* Use the default modes list from drm */ count = drm_add_modes_noedid(connector, XRES_MAX, YRES_MAX); drm_set_preferred_mode(connector, XRES_DEF, YRES_DEF); @@ -58,8 +59,13 @@ int vkms_output_init(struct vkms_device *vkmsdev, int possible_crtc_index) int writeback; unsigned int n; + /* + * Initialize used plane. One primary plane is required to perform the composition. + * + * 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, possible_crtc_index); - if (IS_ERR(primary)) return PTR_ERR(primary); @@ -96,6 +102,10 @@ int vkms_output_init(struct vkms_device *vkmsdev, int possible_crtc_index) DRM_ERROR("Failed to init encoder\n"); goto err_encoder; } + /* + * This is an hardcoded value to select crtc for the encoder. + * 1 here designate the first registered CRTC, the one allocated in [1] + */ encoder->possible_crtcs = 1; ret = drm_connector_attach_encoder(connector, encoder);
Add documentation around vkms_output and its initialization. Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com> --- drivers/gpu/drm/vkms/vkms_drv.h | 81 ++++++++++++++++++++++++++++++++------ drivers/gpu/drm/vkms/vkms_output.c | 12 +++++- 2 files changed, 80 insertions(+), 13 deletions(-)