Re: [PATCH] drm/radeon/ni_dpm: Fix booting bug

[Gustavo A. R. Silva]

Hi Alex,

On 5/10/21 16:17, Alex Deucher wrote:
> On Sun, May 9, 2021 at 6:48 PM Gustavo A. R. Silva
> <gustavoars@xxxxxxxxxx> wrote:
[..]

>>
>> Bug: https://lore.kernel.org/dri-devel/3eedbe78-1fbd-4763-a7f3-ac5665e76a4a@xxxxxxxxxxx/
>> Fixes: 434fb1e7444a ("drm/radeon/nislands_smc.h: Replace one-element array with flexible-array member in struct NISLANDS_SMC_SWSTATE")
>> Cc: stable@xxxxxxxxxxxxxxx
>> Reported-by: Christian Zigotzky <chzigotzky@xxxxxxxxxxx>
>> Tested-by: Christian Zigotzky <chzigotzky@xxxxxxxxxxx>
>> Link: https://lore.kernel.org/dri-devel/9bb5fcbd-daf5-1669-b3e7-b8624b3c36f9@xxxxxxxxxxx/
>> Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
> 
> This seems like a lot of churn just to use flexible arrays.  That
> said, if static checkers are going to keep complaining about single
> element arrays, I don't mind applying these patches since this code is
> not likely to change.  Applied.  Thanks.

This is not only about the one-element arrays. These fixes (together with commits
434fb1e7444a and 96e27e8d919e) allow us to fix more than a dozen of these out-of-bounds
warnings:

drivers/gpu/drm/radeon/ni_dpm.c:2521:20: warning: array subscript 1 is above array bounds of ‘NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct
NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds]
 2521 |   smc_state->levels[i].dpm2.MaxPS =
      |   ~~~~~~~~~~~~~~~~~^~~

which should be fixed in order to globally enable -Warray-bounds. :)

Thanks!
--
Gustavo