diff mbox

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

Message ID 20160926130104.8977-1-marex@denx.de (mailing list archive)
State New, archived
Headers show

Commit Message

Marek Vasut Sept. 26, 2016, 1:01 p.m. UTC
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@denx.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Lucas Stach <l.stach@pengutronix.de>
---
 drivers/gpu/drm/drm_fb_cma_helper.c | 26 ++++++++++++++++++++++++++
 include/drm/drm_fb_cma_helper.h     |  3 +++
 2 files changed, 29 insertions(+)

Comments

Lucas Stach Sept. 28, 2016, 1:55 p.m. UTC | #1
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@denx.de>
> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> Cc: Lucas Stach <l.stach@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

> + *
> + * 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;
>
Marek Vasut Sept. 28, 2016, 8:08 p.m. UTC | #2
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@denx.de>
>> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
>> Cc: Lucas Stach <l.stach@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;
>>  
> 
>
Daniel Vetter Sept. 29, 2016, 9:36 a.m. UTC | #3
On Wed, Sep 28, 2016 at 10:08:21PM +0200, Marek Vasut wrote:
> 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@denx.de>
> >> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> >> Cc: Lucas Stach <l.stach@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.

Imo for helpers that should be put into a specific vhook like this here,
it'd go with that vhooks name. So here drm_fb_cma_prepare_fb.

And then in the kerneldoc also mention where it should be put (both for
drivers using atomic helpers, and those using simple pipe helpers), e.g.
"This should be put into the prepare_fb hook of struct
&drm_plane_helper_funcs."

Please run $ make htmldocs to make sure the docs look pretty and the
generated links are correct.
-Daniel

> > 
> >> + * @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
Marek Vasut Sept. 29, 2016, 9:44 p.m. UTC | #4
On 09/29/2016 11:36 AM, Daniel Vetter wrote:
> On Wed, Sep 28, 2016 at 10:08:21PM +0200, Marek Vasut wrote:
>> 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@denx.de>
>>>> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
>>>> Cc: Lucas Stach <l.stach@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.
> 
> Imo for helpers that should be put into a specific vhook like this here,
> it'd go with that vhooks name. So here drm_fb_cma_prepare_fb.

I have the following right now, I think that's more descriptive as this
function is not preparing the FB in any way.

/**
 * drm_fb_cma_extract_and_attach_fence() - Extract fence from plane and
attach to planestate
 * @plane: Which plane
 * @state: Plane state attach fence to
 *
 * If the plane fb has an dma-buf attached, fish out the exclusive
 * fence and attach it to plane state for the atomic helper to wait
 * on.
 */

> And then in the kerneldoc also mention where it should be put (both for
> drivers using atomic helpers, and those using simple pipe helpers), e.g.
> "This should be put into the prepare_fb hook of struct
> &drm_plane_helper_funcs."
> 
> Please run $ make htmldocs to make sure the docs look pretty and the
> generated links are correct.
> -Daniel
> 
>>>
>>>> + * @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
>
Daniel Vetter Sept. 30, 2016, 9:53 a.m. UTC | #5
On Thu, Sep 29, 2016 at 11:44 PM, Marek Vasut <marex@denx.de> wrote:
> I have the following right now, I think that's more descriptive as this
> function is not preparing the FB in any way.
>
> /**
>  * drm_fb_cma_extract_and_attach_fence() - Extract fence from plane and
> attach to planestate
>  * @plane: Which plane
>  * @state: Plane state attach fence to
>  *
>  * If the plane fb has an dma-buf attached, fish out the exclusive
>  * fence and attach it to plane state for the atomic helper to wait
>  * on.
>  */

That choice of color is ok with me too, but then you need to have a
pile of text to explain where it should be used (i.e. directly as the
prepare_fb hook). And it is a bit inconsistent with all the other
helpers that can be put into hooks directly. Also,
extract_and_attach_fence _is_ officially part of what a driver should
do in their ->prepare_fb hook. Hence I'm still leaning towards that
(and it's shorter!). And with cma there's nothing else to do (dma
memory is always pinned, which is the other thing prepare_fb should
do), so really it's not even a lie: Your function fully prapares a cma
fb for display as expected by th atomic helpers.
-Daniel
Marek Vasut Oct. 2, 2016, 5:19 p.m. UTC | #6
On 09/30/2016 11:53 AM, Daniel Vetter wrote:
> On Thu, Sep 29, 2016 at 11:44 PM, Marek Vasut <marex@denx.de> wrote:
>> I have the following right now, I think that's more descriptive as this
>> function is not preparing the FB in any way.
>>
>> /**
>>  * drm_fb_cma_extract_and_attach_fence() - Extract fence from plane and
>> attach to planestate
>>  * @plane: Which plane
>>  * @state: Plane state attach fence to
>>  *
>>  * If the plane fb has an dma-buf attached, fish out the exclusive
>>  * fence and attach it to plane state for the atomic helper to wait
>>  * on.
>>  */
> 
> That choice of color is ok with me too, but then you need to have a
> pile of text to explain where it should be used (i.e. directly as the
> prepare_fb hook).

There can be more stuff in the prepare_fb hook though.

> And it is a bit inconsistent with all the other
> helpers that can be put into hooks directly. Also,
> extract_and_attach_fence _is_ officially part of what a driver should
> do in their ->prepare_fb hook. Hence I'm still leaning towards that
> (and it's shorter!). And with cma there's nothing else to do (dma
> memory is always pinned, which is the other thing prepare_fb should
> do), so really it's not even a lie: Your function fully prapares a cma
> fb for display as expected by th atomic helpers.

OK, I have no good argument not to go for this one. Unless someone has,
I will redo it.

> -Daniel
>
Daniel Vetter Oct. 3, 2016, 1:54 p.m. UTC | #7
On Sun, Oct 2, 2016 at 7:19 PM, Marek Vasut <marex@denx.de> wrote:
>>> /**
>>>  * drm_fb_cma_extract_and_attach_fence() - Extract fence from plane and
>>> attach to planestate
>>>  * @plane: Which plane
>>>  * @state: Plane state attach fence to
>>>  *
>>>  * If the plane fb has an dma-buf attached, fish out the exclusive
>>>  * fence and attach it to plane state for the atomic helper to wait
>>>  * on.
>>>  */
>>
>> That choice of color is ok with me too, but then you need to have a
>> pile of text to explain where it should be used (i.e. directly as the
>> prepare_fb hook).
>
> There can be more stuff in the prepare_fb hook though.

There's 3 things prepare/cleanup_fb should do:
- pin/upin the backing storage. CMA memory is always pinned, so nothing to do.
- setup/tear down iommu mappings: Already done when allocating CMA
memory, again nothing to do.
- grab fences in prepare.

So for plain cma drivers this hook is indeed the complete
implementation they need for prepare_fb. I guess you could mention in
the kernel-doc that cma based drivers don't need a cleanup_fb, hence
why there is none.
-Daniel
Marek Vasut Oct. 5, 2016, 2:50 p.m. UTC | #8
On 10/03/2016 03:54 PM, Daniel Vetter wrote:
> On Sun, Oct 2, 2016 at 7:19 PM, Marek Vasut <marex@denx.de> wrote:
>>>> /**
>>>>  * drm_fb_cma_extract_and_attach_fence() - Extract fence from plane and
>>>> attach to planestate
>>>>  * @plane: Which plane
>>>>  * @state: Plane state attach fence to
>>>>  *
>>>>  * If the plane fb has an dma-buf attached, fish out the exclusive
>>>>  * fence and attach it to plane state for the atomic helper to wait
>>>>  * on.
>>>>  */
>>>
>>> That choice of color is ok with me too, but then you need to have a
>>> pile of text to explain where it should be used (i.e. directly as the
>>> prepare_fb hook).
>>
>> There can be more stuff in the prepare_fb hook though.
> 
> There's 3 things prepare/cleanup_fb should do:
> - pin/upin the backing storage. CMA memory is always pinned, so nothing to do.
> - setup/tear down iommu mappings: Already done when allocating CMA
> memory, again nothing to do.
> - grab fences in prepare.
> 
> So for plain cma drivers this hook is indeed the complete
> implementation they need for prepare_fb. I guess you could mention in
> the kernel-doc that cma based drivers don't need a cleanup_fb, hence
> why there is none.

OK, understood. I'll roll V3 shortly.
diff mbox

Patch

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
+ * @plane: Which plane
+ * @state: Plane state to check
+ *
+ * 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;