Commit 79f3f1b6 authored by Samson Tam's avatar Samson Tam Committed by Alex Deucher
Browse files

drm/amd/display: fix num_ways overflow error 



[Why]
Helper function calculates num_ways using 32-bit.  But is
 returned as 8-bit.  If num_ways exceeds 8-bit, then it
 reports back the incorrect num_ways and erroneously
 uses MALL when it should not

[How]
Make returned value 32-bit and convert after it checks
 against caps.cache_num_ways, which is under 8-bit

Reviewed-by: default avatarAlvin Lee <alvin.lee2@amd.com>
Acked-by: default avatarRoman Li <roman.li@amd.com>
Signed-off-by: default avatarSamson Tam <samson.tam@amd.com>
Tested-by: default avatarDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent c4066d8b

drivers/gpu/drm/amd/display/dc/hwss/dcn32/dcn32_hwseq.c

+4 −3
Original line number Diff line number Diff line
@@ -217,7 +217,7 @@ static bool dcn32_check_no_memory_request_for_cab(struct dc *dc) 
static uint32_t dcn32_calculate_cab_allocation(struct dc *dc, struct dc_state *ctx)

{

	int i;

	uint8_t num_ways = 0;

	uint32_t num_ways = 0;

	uint32_t mall_ss_size_bytes = 0;



	mall_ss_size_bytes = ctx->bw_ctx.bw.dcn.mall_ss_size_bytes;
@@ -247,7 +247,8 @@ static uint32_t dcn32_calculate_cab_allocation(struct dc *dc, struct dc_state *c 
bool dcn32_apply_idle_power_optimizations(struct dc *dc, bool enable)

{

	union dmub_rb_cmd cmd;

	uint8_t ways, i;

	uint8_t i;

	uint32_t ways;

	int j;

	bool mall_ss_unsupported = false;

	struct dc_plane_state *plane = NULL;
@@ -307,7 +308,7 @@ bool dcn32_apply_idle_power_optimizations(struct dc *dc, bool enable) 
				cmd.cab.header.type = DMUB_CMD__CAB_FOR_SS;

				cmd.cab.header.sub_type = DMUB_CMD__CAB_DCN_SS_FIT_IN_CAB;

				cmd.cab.header.payload_bytes = sizeof(cmd.cab) - sizeof(cmd.cab.header);

				cmd.cab.cab_alloc_ways = ways;

				cmd.cab.cab_alloc_ways = (uint8_t)ways;



				dm_execute_dmub_cmd(dc->ctx, &cmd, DM_DMUB_WAIT_TYPE_NO_WAIT);