Re: [PATCH 08/14] drm/exynos: create a fake mmap offset with gem creation

From: Inki Dae <inki.dae@samsung.com>
To: Daniel Vetter <daniel@ffwll.ch>,
	Joonyoung Shim <jy0922.shim@samsung.com>
Cc: sw0312.kim@samsung.com, dri-devel@lists.freedesktop.org
Subject: Re: [PATCH 08/14] drm/exynos: create a fake mmap offset with gem creation
Date: Tue, 17 Nov 2015 11:53:28 +0900	[thread overview]
Message-ID: <564A96A8.60200@samsung.com> (raw)
In-Reply-To: <20151116162325.GD16848@phenom.ffwll.local>

2015년 11월 17일 01:23에 Daniel Vetter 이(가) 쓴 글:
> On Mon, Nov 16, 2015 at 05:22:42PM +0100, Daniel Vetter wrote:
>> On Tue, Jul 28, 2015 at 05:53:23PM +0900, Joonyoung Shim wrote:
>>> Don't create a fake mmap offset in exynos_drm_gem_dumb_map_offset. If
>>> not, it will call drm_gem_create_mmap_offset whenever user requests
>>> DRM_IOCTL_MODE_MAP_DUMB ioctl.
>>>
>>> Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
>>> ---
>>>  drivers/gpu/drm/exynos/exynos_drm_gem.c | 12 +++++++-----
>>>  1 file changed, 7 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c
>>> index 550d267..c76aa8a 100644
>>> --- a/drivers/gpu/drm/exynos/exynos_drm_gem.c
>>> +++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
>>> @@ -151,6 +151,13 @@ struct exynos_drm_gem_obj *exynos_drm_gem_init(struct drm_device *dev,
>>>  		return ERR_PTR(ret);
>>>  	}
>>>  
>>> +	ret = drm_gem_create_mmap_offset(obj);
>>> +	if (ret < 0) {
>>> +		drm_gem_object_release(obj);
>>> +		kfree(exynos_gem_obj);
>>> +		return ERR_PTR(ret);
>>> +	}
>>> +
>>>  	DRM_DEBUG_KMS("created file object = 0x%x\n", (unsigned int)obj->filp);
>>>  
>>>  	return exynos_gem_obj;
>>> @@ -521,14 +528,9 @@ int exynos_drm_gem_dumb_map_offset(struct drm_file *file_priv,
>>>  		goto unlock;
>>>  	}
>>>  
>>> -	ret = drm_gem_create_mmap_offset(obj);
>>
>> drm_gem_create_mmap_offset internally checks whether it's been already
>> (protected by locks), so this code is perfectly fine. I don't see any
>> justification for this change (but only noticed it because rockchip
>> cargo-culted this change).
> 
> I think it'd be good to revert this to stay consistent with cma helpers
> and other drivers.

At least, seems cma halper doesn't also call drm_gem_create_mmap_offset function
at drm_gem_cma_dumb_map_offset function and calls it at cma creation instead.
So I think now Exynos drm keeps consistent with cma helper.

Thanks,
Inki Dae

> -Daniel
> 
>> -Daniel
>>
>>> -	if (ret)
>>> -		goto out;
>>> -
>>>  	*offset = drm_vma_node_offset_addr(&obj->vma_node);
>>>  	DRM_DEBUG_KMS("offset = 0x%lx\n", (unsigned long)*offset);
>>>  
>>> -out:
>>>  	drm_gem_object_unreference(obj);
>>>  unlock:
>>>  	mutex_unlock(&dev->struct_mutex);
>>> -- 
>>> 1.9.1
>>>
>>> _______________________________________________
>>> dri-devel mailing list
>>> dri-devel@lists.freedesktop.org
>>> http://lists.freedesktop.org/mailman/listinfo/dri-devel
>>
>> -- 
>> Daniel Vetter
>> Software Engineer, Intel Corporation
>> http://blog.ffwll.ch
> 
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