[PATCH] drm/sti: forbid plane on several mixer

[Vincent ABRIOU]

On 09/15/2016 04:27 PM, Ville Syrjälä wrote:
> On Wed, Sep 14, 2016 at 01:40:02PM +0200, Vincent Abriou wrote:
>> When a plane is going to be enabled we re-evaluate the possible crtcs
>> for the associated drm plane. Only the crtc on which the plane should be
>> displayed is considered possible until the plane is disabled.
>> Indeed STI hardware does not allow to dynamically change
>> the plane's crtc/mixer assignment when the plane is in use (gdp is
>> running).
>>
>> Signed-off-by: Vincent Abriou <vincent.abriou at st.com>
>> ---
>>  drivers/gpu/drm/sti/sti_gdp.c   | 15 +++++++++++++++
>>  drivers/gpu/drm/sti/sti_plane.h |  2 ++
>>  2 files changed, 17 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/sti/sti_gdp.c b/drivers/gpu/drm/sti/sti_gdp.c
>> index 3fc62c1..f7cd671 100644
>> --- a/drivers/gpu/drm/sti/sti_gdp.c
>> +++ b/drivers/gpu/drm/sti/sti_gdp.c
>> @@ -71,6 +71,9 @@ static struct gdp_format_to_str {
>>  #define GDP_NODE_NB_BANK        2
>>  #define GDP_NODE_PER_FIELD      2
>>
>> +#define MAIN_CRTC_MASK          BIT(0)
>> +#define AUX_CRTC_MASK           BIT(1)
>> +
>>  struct sti_gdp_node {
>>  	u32 gam_gdp_ctl;
>>  	u32 gam_gdp_agc;
>> @@ -690,6 +693,12 @@ static int sti_gdp_atomic_check(struct drm_plane *drm_plane,
>>  		}
>>  	}
>>
>> +	/* re-evaluate the possible crtcs */
>> +	if (mixer->id == STI_MIXER_MAIN)
>> +		drm_plane->possible_crtcs = MAIN_CRTC_MASK;
>> +	else
>> +		drm_plane->possible_crtcs = AUX_CRTC_MASK;
>
> This stuff isn't meant to be changed dynamically. There's no event for
> telling userspace to re-examine this sort of information.

Yes sure. But by doing this, I let the userspace the ability to fix plan 
assignment by it self by re-evaluating the possible CRTC. Before new 
plane assignment.
The kernel driver is then flexible enough to avoid Kernel crash.

BR
Vincent

>
>> +
>>  	DRM_DEBUG_KMS("CRTC:%d (%s) drm plane:%d (%s)\n",
>>  		      crtc->base.id, sti_mixer_to_str(mixer),
>>  		      drm_plane->base.id, sti_plane_to_str(plane));
>> @@ -846,6 +855,9 @@ static void sti_gdp_atomic_disable(struct drm_plane *drm_plane,
>>  {
>>  	struct sti_plane *plane = to_sti_plane(drm_plane);
>>
>> +	/* restore possible crtcs value with the initial value */
>> +	drm_plane->possible_crtcs = plane->init_possible_crtcs;
>> +
>>  	if (!drm_plane->crtc) {
>>  		DRM_DEBUG_DRIVER("drm plane:%d not enabled\n",
>>  				 drm_plane->base.id);
>> @@ -917,6 +929,9 @@ struct drm_plane *sti_gdp_create(struct drm_device *drm_dev,
>>
>>  	sti_gdp_init(gdp);
>>
>> +	/* store the initial value of possible crtcs */
>> +	gdp->plane.init_possible_crtcs = possible_crtcs;
>> +
>>  	res = drm_universal_plane_init(drm_dev, &gdp->plane.drm_plane,
>>  				       possible_crtcs,
>>  				       &sti_gdp_plane_helpers_funcs,
>> diff --git a/drivers/gpu/drm/sti/sti_plane.h b/drivers/gpu/drm/sti/sti_plane.h
>> index ce3e8d6..70c5312 100644
>> --- a/drivers/gpu/drm/sti/sti_plane.h
>> +++ b/drivers/gpu/drm/sti/sti_plane.h
>> @@ -66,12 +66,14 @@ struct sti_fps_info {
>>   * @plane:              drm plane it is bound to (if any)
>>   * @desc:               plane type & id
>>   * @status:             to know the status of the plane
>> + * @init_possile_crtcs: store the initial possible crtc value
>>   * @fps_info:           frame per second info
>>   */
>>  struct sti_plane {
>>  	struct drm_plane drm_plane;
>>  	enum sti_plane_desc desc;
>>  	enum sti_plane_status status;
>> +	u32 init_possible_crtcs;
>>  	struct sti_fps_info fps_info;
>>  };
>>
>> --
>> 1.9.1
>>
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>