[PATCH 15/21] drm/rcar-du: Use GEM CMA object functions

[Kieran Bingham]

On 25/05/2020 13:49, Thomas Zimmermann wrote:
> Hi
> 
> Am 22.05.20 um 22:12 schrieb Laurent Pinchart:
>> Hi Thomas,
>>
>> Thank you for the patch.
>>
>> On Fri, May 22, 2020 at 03:52:40PM +0200, Thomas Zimmermann wrote:
>>> The rcar-du driver uses the default implementation for CMA functions;
>>> except for the .dumb_create callback. The __DRM_GEM_CMA_DRIVER_OPS macro
>>> now sets these defaults and .dumb_create in struct drm_driver. All
>>> remaining operations are provided by CMA GEM object functions.
>>>
>>> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
>>> ---
>>>  drivers/gpu/drm/rcar-du/rcar_du_drv.c | 11 +----------
>>>  1 file changed, 1 insertion(+), 10 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_drv.c b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
>>> index 3e67cf70f0402..3728038cec1d1 100644
>>> --- a/drivers/gpu/drm/rcar-du/rcar_du_drv.c
>>> +++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
>>> @@ -476,16 +476,7 @@ DEFINE_DRM_GEM_CMA_FOPS(rcar_du_fops);
>>>  
>>>  static struct drm_driver rcar_du_driver = {
>>>  	.driver_features	= DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
>>> -	.gem_free_object_unlocked = drm_gem_cma_free_object,
>>> -	.gem_vm_ops		= &drm_gem_cma_vm_ops,
>>> -	.prime_handle_to_fd	= drm_gem_prime_handle_to_fd,
>>> -	.prime_fd_to_handle	= drm_gem_prime_fd_to_handle,
>>> -	.gem_prime_get_sg_table	= drm_gem_cma_prime_get_sg_table,
>>> -	.gem_prime_import_sg_table = drm_gem_cma_prime_import_sg_table,
>>> -	.gem_prime_vmap		= drm_gem_cma_prime_vmap,
>>> -	.gem_prime_vunmap	= drm_gem_cma_prime_vunmap,
>>> -	.gem_prime_mmap		= drm_gem_cma_prime_mmap,
>>> -	.dumb_create		= rcar_du_dumb_create,
>>> +	__DRM_GEM_CMA_DRIVER_OPS(rcar_du_dumb_create),
>>
>> Your __DRM_GEM_CMA_DRIVER_OPS is defined as
>>
>> #define __DRM_GEM_CMA_DRIVER_OPS(__dumb_create) \
>>         .gem_create_object      = drm_cma_gem_create_object_default_funcs, \
>>         .dumb_create            = (__dumb_create), \
>>         .prime_handle_to_fd     = drm_gem_prime_handle_to_fd, \
>>         .prime_fd_to_handle     = drm_gem_prime_fd_to_handle, \
>>         .gem_prime_import_sg_table = drm_gem_cma_prime_import_sg_table_vmap, \
>>         .gem_prime_mmap         = drm_gem_prime_mmap
>>
>> The patch thus introduces several changes:
>>
>> - drm_gem_cma_prime_import_sg_table_vmap() is used instead of
>>   drm_gem_cma_prime_import_sg_table() combined with .gem_prime_vmap()
>>   and .gem_prime_vunmap(). I believe that's fine, but splitting that
>>   change in a separate commit, or at the very least explaining it in
>>   details in the commit message, would make review easier.
>>
>> - .gem_create_object() is now set. That seems to be OK, but I'm not sure
>>   to grasp all the implications. This should also be explained in the
>>   commit message, and ideally split to a separate patch.
> 
> That's relevant during object creation and sets the object functions.
> See one of my other replies for how this can go away after all CMA
> drivers have been updated to GEM object functions.
> 
> 
>>
>> - drm_gem_cma_prime_mmap() is replaced with drm_gem_prime_mmap(). Same
>>   comments :-)
> 
> I relied on the aspeed driver to be correct. After Sam's comment on
> that, I read the code once again several times. The original
> implementation clears VM_PFNMAP. And I cannot find that code any longer.
> Going back to the original function might be better.
> 
> 
>>
>> This patch hides way too many changes in what is documented as just
>> innocent refactoring. It seems other drivers are affected too.
> 
> Could you test the patchset? I don't have the HW.

Digging out the branch you provided elsewhere in this thread:

>>> Could you boot-test with the patchset applied?
>>
>> Yes, if you have a git branch I can just build and boot I can
>> do it quickly!
>
> Fantastic! It's the cma-objfuncs branch of
>
> https://gitlab.freedesktop.org/tzimmermann/linux.git

I have successfully run our display tests with your patches here on an
R-Car H3 Salvator-XS(-es2).

Tested-by: Kieran Bingham <kieran.bingham+renesas at ideasonboard.com>



> Best regards
> Thomas
> 
>>
>>>  	.fops			= &rcar_du_fops,
>>>  	.name			= "rcar-du",
>>>  	.desc			= "Renesas R-Car Display Unit",
>>
>