[PATCH] drm/msm/dpu: add DSC range checking during resource reservation

[Dmitry Baryshkov]

On 12/04/2023 00:09, Kuogee Hsieh wrote:
> Perform DSC range checking to make sure correct DSC is requested before
> reserve resource for it.
> 
> Fixes: c985d7bb64ff ("drm/msm/disp/dpu1: Add DSC support in RM")

$ git log -p -1 c985d7bb64ff
fatal: ambiguous argument 'c985d7bb64ff': unknown revision or path not 
in the working tree.

I assume this was generated against some internal tree. Please. Please. 
Don't do this again. I hoped that this was pointed out ages ago, but 
probably not. No fixes, commits, tests against internal trees, no matter 
how precious they are to you.

> Signed-off-by: Kuogee Hsieh <quic_khsieh at quicinc.com>
> ---
>   drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c | 10 +++++++++-
>   1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c
> index f4dda88..95e58f1 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c
> @@ -1,6 +1,7 @@
>   // SPDX-License-Identifier: GPL-2.0-only
>   /*
>    * Copyright (c) 2016-2018, The Linux Foundation. All rights reserved.
> + * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved.
>    */
>   
>   #define pr_fmt(fmt)	"[drm:%s] " fmt, __func__
> @@ -250,6 +251,11 @@ int dpu_rm_init(struct dpu_rm *rm,
>   		struct dpu_hw_dsc *hw;
>   		const struct dpu_dsc_cfg *dsc = &cat->dsc[i];
>   
> +		if (dsc->id < DSC_0 || dsc->id >= DSC_MAX) {
> +			DPU_ERROR("skip dsc %d with invalid id\n", dsc->id);
> +			continue;
> +		}
> +
>   		hw = dpu_hw_dsc_init(dsc->id, mmio, cat);
>   		if (IS_ERR_OR_NULL(hw)) {
>   			rc = PTR_ERR(hw);
> @@ -557,8 +563,10 @@ static int _dpu_rm_make_reservation(
>   	}
>   
>   	ret  = _dpu_rm_reserve_dsc(rm, global_state, enc, &reqs->topology);
> -	if (ret)
> +	if (ret) {
> +		DPU_ERROR("unable to find appropriate DSC\n");
>   		return ret;
> +	}
>   
>   	return ret;
>   }

-- 
With best wishes
Dmitry