[PATCH 1/2] drm/amd/display: fix array lenth error.

[Harry Wentland]

True, we should probably always keep one level even if it's larger than
max_clock, but output a big fat warning message when that happens.

Harry

On 2017-02-06 10:36 AM, Zhu, Rex wrote:
> seems reasonable.
> 
> 
> but i think need to check num_levels  can't be 0. in some case, there is
> only one level of mclk, and higher than the max validation clocks.. and
> will lead kernel panic.
> 
> 
> Best Regards
> 
> Rex
> 
> ------------------------------------------------------------------------
> *From:* Wentland, Harry
> *Sent:* Monday, February 6, 2017 10:54:24 PM
> *To:* Zhu, Rex; amd-gfx at lists.freedesktop.org
> *Subject:* Re: [PATCH 1/2] drm/amd/display: fix array lenth error.
>  
> On 2017-02-06 12:08 AM, Rex Zhu wrote:
>> Change-Id: I09011c5e6d5493db7e3d9a7ff7ab8c871a8db862
>> Signed-off-by: Rex Zhu <Rex.Zhu at amd.com>
>> ---
>>  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_services.c | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_services.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_services.c
>> index 5af27aa..50576c6 100644
>> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_services.c
>> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_services.c
>> @@ -358,7 +358,7 @@ bool dm_pp_get_clock_levels_by_type(
>>                                 * non-boosted one. */
>>                                DRM_INFO("DM_PPLIB: reducing engine clock level from %d to %d\n",
>>                                                dc_clks->num_levels, i + 1);
>> -                             dc_clks->num_levels = i;
>> +                             dc_clks->num_levels = i + 1;
> 
> It seems to me the DRM_INFO print is wrong here, not the actual
> assignment. We're setting num_levels to the current index if the clocks
> for that index are higher than the max validation clocks, hence this
> index now should become num_levels.
> 
>>                                break;
>>                        }
>>                }
>> @@ -367,7 +367,7 @@ bool dm_pp_get_clock_levels_by_type(
>>                        if (dc_clks->clocks_in_khz[i] > validation_clks.memory_max_clock) {
>>                                DRM_INFO("DM_PPLIB: reducing memory clock level from %d to %d\n",
>>                                                dc_clks->num_levels, i + 1);
>> -                             dc_clks->num_levels = i;
>> +                             dc_clks->num_levels = i + 1;
>>                                break;
>>                        }
>>                }
>> 
> 
> Same comment as above.
> 
> Harry