[PATCH 1/2] drm/fb_cma_helper: Add drm_fb_cma_setup_fence() helper

[Marek Vasut]

On 09/28/2016 03:55 PM, Lucas Stach wrote:
> Hi Marek,
> 
> Am Montag, den 26.09.2016, 15:01 +0200 schrieb Marek Vasut:
>> Add new drm_fb_cma_setup_fence() helper function extracted from the
>> imx-drm driver. This function checks if the plane has DMABUF attached
>> to it and if so, sets up the fence on which the atomic helper can wait.
>>
>> Signed-off-by: Marek Vasut <marex at denx.de>
>> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
>> Cc: Lucas Stach <l.stach at pengutronix.de>
>> ---
>>  drivers/gpu/drm/drm_fb_cma_helper.c | 26 ++++++++++++++++++++++++++
>>  include/drm/drm_fb_cma_helper.h     |  3 +++
>>  2 files changed, 29 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/drm_fb_cma_helper.c b/drivers/gpu/drm/drm_fb_cma_helper.c
>> index 1fd6eac..2441707 100644
>> --- a/drivers/gpu/drm/drm_fb_cma_helper.c
>> +++ b/drivers/gpu/drm/drm_fb_cma_helper.c
>> @@ -23,8 +23,10 @@
>>  #include <drm/drm_crtc_helper.h>
>>  #include <drm/drm_gem_cma_helper.h>
>>  #include <drm/drm_fb_cma_helper.h>
>> +#include <linux/dma-buf.h>
>>  #include <linux/dma-mapping.h>
>>  #include <linux/module.h>
>> +#include <linux/reservation.h>
>>  
>>  #define DEFAULT_FBDEFIO_DELAY_MS 50
>>  
>> @@ -265,6 +267,30 @@ struct drm_gem_cma_object *drm_fb_cma_get_gem_obj(struct drm_framebuffer *fb,
>>  }
>>  EXPORT_SYMBOL_GPL(drm_fb_cma_get_gem_obj);
>>  
>> +/**
>> + * drm_fb_cma_setup_fence() - Set up the fence for atomic helper to wait on
> 
> I don't really like the naming of the helper. It's not setting up any
> fence, it's either extracting it from the plane and/or attaching it to
> the planestate, so I would have expected the name to include extract or
> attach.
> 
>> + * @plane: Which plane
>> + * @state: Plane state to check
> 
> s/check/attach fence to

Both fixed in V2, thanks.

>> + *
>> + * If the plane fb has an dma-buf attached, fish out the exclusive
>> + * fence for the atomic helper to wait on.
>> + */
>> +void drm_fb_cma_setup_fence(struct drm_plane *plane,
>> +			    struct drm_plane_state *state)
>> +{
>> +	struct dma_buf *dma_buf;
>> +
>> +	if ((plane->state->fb == state->fb) || !state->fb)
>> +		return;
>> +
>> +	dma_buf = drm_fb_cma_get_gem_obj(state->fb, 0)->base.dma_buf;
>> +	if (!dma_buf)
>> +		return;
>> +
>> +	state->fence = reservation_object_get_excl_rcu(dma_buf->resv);
>> +}
>> +EXPORT_SYMBOL_GPL(drm_fb_cma_setup_fence);
>> +
>>  #ifdef CONFIG_DEBUG_FS
>>  static void drm_fb_cma_describe(struct drm_framebuffer *fb, struct seq_file *m)
>>  {
>> diff --git a/include/drm/drm_fb_cma_helper.h b/include/drm/drm_fb_cma_helper.h
>> index f313211..fc122d3 100644
>> --- a/include/drm/drm_fb_cma_helper.h
>> +++ b/include/drm/drm_fb_cma_helper.h
>> @@ -41,6 +41,9 @@ struct drm_framebuffer *drm_fb_cma_create(struct drm_device *dev,
>>  struct drm_gem_cma_object *drm_fb_cma_get_gem_obj(struct drm_framebuffer *fb,
>>  	unsigned int plane);
>>  
>> +void drm_fb_cma_setup_fence(struct drm_plane *plane,
>> +			    struct drm_plane_state *state);
>> +
>>  #ifdef CONFIG_DEBUG_FS
>>  struct seq_file;
>>  
> 
> 


-- 
Best regards,
Marek Vasut