[PATCH] drm/amd/display: Fix NULL pointer dereference at hibernate

[Harry Wentland]

On 2023-11-28 19:35, Mario Limonciello wrote:
> During hibernate sequence the source context might not have a clk_mgr.
> So don't use it to look for DML2 support.
> 
> Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2980
> Fixes: a2815ada8616 ("drm/amd/display: Introduce DML2")
> Signed-off-by: Mario Limonciello <mario.limonciello at amd.com>

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

Harry

> ---
>   drivers/gpu/drm/amd/display/dc/core/dc_resource.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
> index f3a9fdd2340d..e1c02527d04a 100644
> --- a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
> +++ b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
> @@ -4554,7 +4554,7 @@ void dc_resource_state_copy_construct(
>   	struct dml2_context *dml2 = NULL;
>   
>   	// Need to preserve allocated dml2 context
> -	if (src_ctx->clk_mgr->ctx->dc->debug.using_dml2)
> +	if (src_ctx->clk_mgr && src_ctx->clk_mgr->ctx->dc->debug.using_dml2)
>   		dml2 = dst_ctx->bw_ctx.dml2;
>   #endif
>   
> @@ -4562,7 +4562,7 @@ void dc_resource_state_copy_construct(
>   
>   #ifdef CONFIG_DRM_AMD_DC_FP
>   	// Preserve allocated dml2 context
> -	if (src_ctx->clk_mgr->ctx->dc->debug.using_dml2)
> +	if (src_ctx->clk_mgr && src_ctx->clk_mgr->ctx->dc->debug.using_dml2)
>   		dst_ctx->bw_ctx.dml2 = dml2;
>   #endif
>