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

[Zhu, Rex]

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
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