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* [PATCH] drm/amdgpu: drop redundant null-pointer checks in amdgpu_ttm_tt_populate() and amdgpu_ttm_tt_unpopulate()
@ 2021-08-04  1:51 Tuo Li
  2021-08-04  6:49 ` Christian König
  0 siblings, 1 reply; 3+ messages in thread
From: Tuo Li @ 2021-08-04  1:51 UTC (permalink / raw)
  To: alexander.deucher, christian.koenig, Xinhui.Pan, airlied, daniel,
	sumit.semwal, airlied, Felix.Kuehling, Oak.Zeng, nirmoy.das,
	tzimmermann, Philip.Yang
  Cc: amd-gfx, dri-devel, linux-kernel, linux-media, linaro-mm-sig,
	baijiaju1990, Tuo Li, TOTE Robot

The varialbe gtt in the function amdgpu_ttm_tt_populate() and
amdgpu_ttm_tt_unpopulate() is guaranteed to be not NULL in the context.
Thus the null-pointer checks are redundant and can be dropped.

Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Tuo Li <islituo@gmail.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 3a55f08e00e1..719539bd6c44 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -1121,7 +1121,7 @@ static int amdgpu_ttm_tt_populate(struct ttm_device *bdev,
 	struct amdgpu_ttm_tt *gtt = (void *)ttm;
 
 	/* user pages are bound by amdgpu_ttm_tt_pin_userptr() */
-	if (gtt && gtt->userptr) {
+	if (gtt->userptr) {
 		ttm->sg = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
 		if (!ttm->sg)
 			return -ENOMEM;
@@ -1146,7 +1146,7 @@ static void amdgpu_ttm_tt_unpopulate(struct ttm_device *bdev,
 	struct amdgpu_ttm_tt *gtt = (void *)ttm;
 	struct amdgpu_device *adev;
 
-	if (gtt && gtt->userptr) {
+	if (gtt->userptr) {
 		amdgpu_ttm_tt_set_user_pages(ttm, NULL);
 		kfree(ttm->sg);
 		ttm->sg = NULL;
-- 
2.25.1


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] drm/amdgpu: drop redundant null-pointer checks in amdgpu_ttm_tt_populate() and amdgpu_ttm_tt_unpopulate()
  2021-08-04  1:51 [PATCH] drm/amdgpu: drop redundant null-pointer checks in amdgpu_ttm_tt_populate() and amdgpu_ttm_tt_unpopulate() Tuo Li
@ 2021-08-04  6:49 ` Christian König
  2021-08-05  4:32   ` Alex Deucher
  0 siblings, 1 reply; 3+ messages in thread
From: Christian König @ 2021-08-04  6:49 UTC (permalink / raw)
  To: Tuo Li, alexander.deucher, Xinhui.Pan, airlied, daniel,
	sumit.semwal, airlied, Felix.Kuehling, Oak.Zeng, nirmoy.das,
	tzimmermann, Philip.Yang
  Cc: amd-gfx, dri-devel, linux-kernel, linux-media, linaro-mm-sig,
	baijiaju1990, TOTE Robot

Am 04.08.21 um 03:51 schrieb Tuo Li:
> The varialbe gtt in the function amdgpu_ttm_tt_populate() and
> amdgpu_ttm_tt_unpopulate() is guaranteed to be not NULL in the context.
> Thus the null-pointer checks are redundant and can be dropped.
>
> Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
> Signed-off-by: Tuo Li <islituo@gmail.com>

Reviewed-by: Christian König <christian.koenig@amd.com>

> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index 3a55f08e00e1..719539bd6c44 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -1121,7 +1121,7 @@ static int amdgpu_ttm_tt_populate(struct ttm_device *bdev,
>   	struct amdgpu_ttm_tt *gtt = (void *)ttm;
>   
>   	/* user pages are bound by amdgpu_ttm_tt_pin_userptr() */
> -	if (gtt && gtt->userptr) {
> +	if (gtt->userptr) {
>   		ttm->sg = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
>   		if (!ttm->sg)
>   			return -ENOMEM;
> @@ -1146,7 +1146,7 @@ static void amdgpu_ttm_tt_unpopulate(struct ttm_device *bdev,
>   	struct amdgpu_ttm_tt *gtt = (void *)ttm;
>   	struct amdgpu_device *adev;
>   
> -	if (gtt && gtt->userptr) {
> +	if (gtt->userptr) {
>   		amdgpu_ttm_tt_set_user_pages(ttm, NULL);
>   		kfree(ttm->sg);
>   		ttm->sg = NULL;


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] drm/amdgpu: drop redundant null-pointer checks in amdgpu_ttm_tt_populate() and amdgpu_ttm_tt_unpopulate()
  2021-08-04  6:49 ` Christian König
@ 2021-08-05  4:32   ` Alex Deucher
  0 siblings, 0 replies; 3+ messages in thread
From: Alex Deucher @ 2021-08-05  4:32 UTC (permalink / raw)
  To: Christian König
  Cc: Tuo Li, Deucher, Alexander, xinhui pan, Dave Airlie,
	Daniel Vetter, Sumit Semwal, Dave Airlie, Kuehling, Felix,
	Oak Zeng, Nirmoy Das, Thomas Zimmermann, Yang, Philip,
	amd-gfx list, Maling list - DRI developers, LKML, linux-media,
	moderated list:DMA BUFFER SHARING FRAMEWORK, Jia-Ju Bai,
	TOTE Robot

Applied.  Thanks!

Alex

On Wed, Aug 4, 2021 at 2:49 AM Christian König <christian.koenig@amd.com> wrote:
>
> Am 04.08.21 um 03:51 schrieb Tuo Li:
> > The varialbe gtt in the function amdgpu_ttm_tt_populate() and
> > amdgpu_ttm_tt_unpopulate() is guaranteed to be not NULL in the context.
> > Thus the null-pointer checks are redundant and can be dropped.
> >
> > Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
> > Signed-off-by: Tuo Li <islituo@gmail.com>
>
> Reviewed-by: Christian König <christian.koenig@amd.com>
>
> > ---
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 4 ++--
> >   1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> > index 3a55f08e00e1..719539bd6c44 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> > @@ -1121,7 +1121,7 @@ static int amdgpu_ttm_tt_populate(struct ttm_device *bdev,
> >       struct amdgpu_ttm_tt *gtt = (void *)ttm;
> >
> >       /* user pages are bound by amdgpu_ttm_tt_pin_userptr() */
> > -     if (gtt && gtt->userptr) {
> > +     if (gtt->userptr) {
> >               ttm->sg = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
> >               if (!ttm->sg)
> >                       return -ENOMEM;
> > @@ -1146,7 +1146,7 @@ static void amdgpu_ttm_tt_unpopulate(struct ttm_device *bdev,
> >       struct amdgpu_ttm_tt *gtt = (void *)ttm;
> >       struct amdgpu_device *adev;
> >
> > -     if (gtt && gtt->userptr) {
> > +     if (gtt->userptr) {
> >               amdgpu_ttm_tt_set_user_pages(ttm, NULL);
> >               kfree(ttm->sg);
> >               ttm->sg = NULL;
>

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2021-08-05  4:33 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2021-08-04  1:51 [PATCH] drm/amdgpu: drop redundant null-pointer checks in amdgpu_ttm_tt_populate() and amdgpu_ttm_tt_unpopulate() Tuo Li
2021-08-04  6:49 ` Christian König
2021-08-05  4:32   ` Alex Deucher

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