Re: [git pull] drm for 5.13-rc1

[Mikita Lipski <mlipski@amd.com>]

Hi Linus,

The patch to fix the warning is here 
(https://www.spinics.net/lists/amd-gfx/msg61614.html)

I guess it just didn't propagate all the way to the release.
Can it still be pulled into 5.13-rc1 release?


From: Mikita Lipski <mikita.lipski@xxxxxxx>

[why]
Previous statement would always evaluate to true
making it meaningless
[how]
Just check if a connector is MST by checking if its port exists.

Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: Mikita Lipski <mikita.lipski@xxxxxxx>
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@xxxxxxx>
Acked-by: Wayne Lin <waynelin@xxxxxxx>
---
  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c 
b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
index 656bc8f00a42..8bf0b566612b 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
@@ -3030,7 +3030,7 @@ static int trigger_hpd_mst_set(void *data, u64 val)
  			if (!aconnector->dc_link)
  				continue;

-			if (!(aconnector->port && &aconnector->mst_port->mst_mgr))
+			if (!aconnector->mst_port)
  				continue;

  			link = aconnector->dc_link;
-- 
2.17.1



Thanks,
Mikita


On 2021-04-28 6:21 p.m., Linus Torvalds wrote:
> On Tue, Apr 27, 2021 at 8:32 PM Dave Airlie <airlied@gmail.com> wrote:
>>
>> This is the main drm pull request for 5.13. The usual lots of work all
>> over the place. [...]
>>
>> Mikita Lipski:
>>        drm/amd/display: Add MST capability to trigger_hotplug interface
> 
> Hmm. I've already merged this, but my clang build shows that this looks buggy:
> 
> drivers/gpu/drm/amd/amdgpu/amdgpu_dm/amdgpu_dm_debugfs.c:3015:53:
> warning: address of 'aconnector->mst_port->mst_mgr' will always
> evaluate to 'true' [-Wpointer-bool-conversion]
>                          if (!(aconnector->port &&
> &aconnector->mst_port->mst_mgr))
>                                                 ~~  ~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
> 
> and yeah, checking for the address of a member of a structure benign
> NULL doesn't really work.
> 
> I'm assuming the '&' is just a left-over cut-and-paste error or something.
> 
> Please fix after reviewing (I'm not going to blindly just remove the
> '&' just to silence the warning, since I don't know the code).
> 
>                  Linus
>