Commit 245a0221 authored May 12, 2020 by Aric Cyr Committed by Alex Deucher May 28, 2020

drm/amd/display: Guard against invalid array access



[Why]
There are scenarios where no OPP is assigned to an OTG so its value is
0xF which is outside the size of the OPP array causing a potential
driver crash.

[How]
Change the assert to an early return to guard against access.  If
there's no OPP assigned already, then OTG will be blank anyways so no
functionality should be lost.

Signed-off-by: Aric Cyr <aric.cyr@amd.com>
Reviewed-by: Zhan Liu <Zhan.Liu@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

parent 15ce104c

drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c

+10 −2

Original line number	Diff line number	Diff line
		@@ -291,12 +291,20 @@ void dcn20_init_blank(

		/* get the OPTC source */
		tg->funcs->get_optc_source(tg, &num_opps, &opp_id_src0, &opp_id_src1);
		ASSERT(opp_id_src0 < dc->res_pool->res_cap->num_opp);

		if (opp_id_src0 >= dc->res_pool->res_cap->num_opp) {
		ASSERT(false);
		return;
		}
		opp = dc->res_pool->opps[opp_id_src0];

		if (num_opps == 2) {
		otg_active_width = otg_active_width / 2;
		ASSERT(opp_id_src1 < dc->res_pool->res_cap->num_opp);

		if (opp_id_src1 >= dc->res_pool->res_cap->num_opp) {
		ASSERT(false);
		return;
		}
		bottom_opp = dc->res_pool->opps[opp_id_src1];
		}