[PATCH] drm/amd/display: Fix incorrectly reading prev_dppclk

[Harry Wentland]

On 2022-05-10 14:34, Bhawanpreet Lakha wrote:
> From: Bhawanpreet Lakha <Bhawanpreet.Lakha at amd.corp-partner.google.com>
> 
> [Why]
> we save the prev_dppclk value using "dpp_inst" but when reading this
> value we use the index "i". In a case where a pipe is fused off we can
> end up reading the incorrect instance because i != dpp_inst in this
> case.
> 
> [How]
> read the prev_dppclk using dpp_inst instead of i
> 
> Signed-off-by: Bhawanpreet Lakha Bhawanpreet.Lakha at amd.com
> Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin at amd.com>

Reviewed-by: Harry Wentland <harry.wentland at amd.com>

Harry

> ---
>  drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c
> index 02943ca65807..cf1b5f354ae9 100644
> --- a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c
> +++ b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c
> @@ -122,7 +122,7 @@ static void rn_update_clocks_update_dpp_dto(struct clk_mgr_internal *clk_mgr,
>  		dpp_inst = clk_mgr->base.ctx->dc->res_pool->dpps[i]->inst;
>  		dppclk_khz = context->res_ctx.pipe_ctx[i].plane_res.bw.dppclk_khz;
>  
> -		prev_dppclk_khz = clk_mgr->dccg->pipe_dppclk_khz[i];
> +		prev_dppclk_khz = clk_mgr->dccg->pipe_dppclk_khz[dpp_inst];
>  
>  		if (safe_to_lower || prev_dppclk_khz < dppclk_khz)
>  			clk_mgr->dccg->funcs->update_dpp_dto(