[PATCH] drm: self_refresh: Fix a reversed condition in drm_self_refresh_helper_cleanup()

[PATCH] drm: self_refresh: Fix a reversed condition in drm_self_refresh_helper_cleanup()

[Dan Carpenter]

This test is flipped around so it either leads to a memory leak or a
NULL dereference.

Fixes: 1452c25b0e60 ("drm: Add helpers to kick off self refresh mode in drivers")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
I'm not totally sure what the prefered patch prefix for this code.  One
thing that would help is when we're adding new files we should specify
the prefix that they're going to use:

- drm: Add helpers to kick off self refresh mode in drivers
+ drm: refresh mode: Add helpers to kick off self refresh mode in drivers

It's a small thing and email always sounds whiny but I'm sending this
suggestion to everyone today so...

 drivers/gpu/drm/drm_self_refresh_helper.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_self_refresh_helper.c b/drivers/gpu/drm/drm_self_refresh_helper.c
index 2b3daaf77841..e0d2ad1f070c 100644
--- a/drivers/gpu/drm/drm_self_refresh_helper.c
+++ b/drivers/gpu/drm/drm_self_refresh_helper.c
@@ -205,7 +205,7 @@ void drm_self_refresh_helper_cleanup(struct drm_crtc *crtc)
 	struct drm_self_refresh_data *sr_data = crtc->self_refresh_data;
 
 	/* Helper is already uninitialized */
-	if (sr_data)
+	if (!sr_data)
 		return;
 
 	crtc->self_refresh_data = NULL;
-- 
2.20.1

Re: [PATCH] drm: self_refresh: Fix a reversed condition in drm_self_refresh_helper_cleanup()

[Sean Paul]

On Wed, Jun 19, 2019 at 01:01:41PM +0300, Dan Carpenter wrote:
> This test is flipped around so it either leads to a memory leak or a
> NULL dereference.
> 
> Fixes: 1452c25b0e60 ("drm: Add helpers to kick off self refresh mode in drivers")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Thanks for the patch and your bug report! I've applied this to -misc-next and
will dig into the bug report shortly.

> ---
> I'm not totally sure what the prefered patch prefix for this code.  One
> thing that would help is when we're adding new files we should specify
> the prefix that they're going to use:
> 
> - drm: Add helpers to kick off self refresh mode in drivers
> + drm: refresh mode: Add helpers to kick off self refresh mode in drivers
> 
> It's a small thing and email always sounds whiny but I'm sending this
> suggestion to everyone today so...

There's no hard rule. For drivers we use drm/<driver>, and for core people
use drm or drm/<file>.

> 
>  drivers/gpu/drm/drm_self_refresh_helper.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/drm_self_refresh_helper.c b/drivers/gpu/drm/drm_self_refresh_helper.c
> index 2b3daaf77841..e0d2ad1f070c 100644
> --- a/drivers/gpu/drm/drm_self_refresh_helper.c
> +++ b/drivers/gpu/drm/drm_self_refresh_helper.c
> @@ -205,7 +205,7 @@ void drm_self_refresh_helper_cleanup(struct drm_crtc *crtc)
>  	struct drm_self_refresh_data *sr_data = crtc->self_refresh_data;
>  
>  	/* Helper is already uninitialized */
> -	if (sr_data)
> +	if (!sr_data)
>  		return;
>  
>  	crtc->self_refresh_data = NULL;
> -- 
> 2.20.1
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Sean Paul, Software Engineer, Google / Chromium OS

Re: [PATCH] drm: self_refresh: Fix a reversed condition in drm_self_refresh_helper_cleanup()

[Jani Nikula]

On Wed, 19 Jun 2019, Sean Paul <sean@poorly.run> wrote:
> On Wed, Jun 19, 2019 at 01:01:41PM +0300, Dan Carpenter wrote:
>> This test is flipped around so it either leads to a memory leak or a
>> NULL dereference.
>> 
>> Fixes: 1452c25b0e60 ("drm: Add helpers to kick off self refresh mode in drivers")
>> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
>
> Thanks for the patch and your bug report! I've applied this to -misc-next and
> will dig into the bug report shortly.
>
>> ---
>> I'm not totally sure what the prefered patch prefix for this code.  One
>> thing that would help is when we're adding new files we should specify
>> the prefix that they're going to use:
>> 
>> - drm: Add helpers to kick off self refresh mode in drivers
>> + drm: refresh mode: Add helpers to kick off self refresh mode in drivers
>> 
>> It's a small thing and email always sounds whiny but I'm sending this
>> suggestion to everyone today so...
>
> There's no hard rule. For drivers we use drm/<driver>, and for core people
> use drm or drm/<file>.

checkpatch.pl should have a git log popularity contest based check for
the prefix. For new files, first come first served. ;)

BR,
Jani.


>
>> 
>>  drivers/gpu/drm/drm_self_refresh_helper.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> diff --git a/drivers/gpu/drm/drm_self_refresh_helper.c b/drivers/gpu/drm/drm_self_refresh_helper.c
>> index 2b3daaf77841..e0d2ad1f070c 100644
>> --- a/drivers/gpu/drm/drm_self_refresh_helper.c
>> +++ b/drivers/gpu/drm/drm_self_refresh_helper.c
>> @@ -205,7 +205,7 @@ void drm_self_refresh_helper_cleanup(struct drm_crtc *crtc)
>>  	struct drm_self_refresh_data *sr_data = crtc->self_refresh_data;
>>  
>>  	/* Helper is already uninitialized */
>> -	if (sr_data)
>> +	if (!sr_data)
>>  		return;
>>  
>>  	crtc->self_refresh_data = NULL;
>> -- 
>> 2.20.1
>> 
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel@lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Jani Nikula, Intel Open Source Graphics Center