From: Srinivasan Shanmugam srinivasan.shanmugam@amd.com
[ Upstream commit 4b6377f0e96085cbec96eb7f0b282430ccdd3d75 ]
This commit addresses a potential null pointer dereference issue in the `dcn401_init_hw` function. The issue could occur when `dc->clk_mgr` or `dc->clk_mgr->funcs` is null.
The fix adds a check to ensure `dc->clk_mgr` and `dc->clk_mgr->funcs` is not null before accessing its functions. This prevents a potential null pointer dereference.
Reported by smatch: drivers/gpu/drm/amd/amdgpu/../display/dc/hwss/dcn401/dcn401_hwseq.c:416 dcn401_init_hw() error: we previously assumed 'dc->clk_mgr' could be null (see line 225)
Cc: Tom Chung chiahsuan.chung@amd.com Cc: Rodrigo Siqueira Rodrigo.Siqueira@amd.com Cc: Roman Li roman.li@amd.com Cc: Alex Hung alex.hung@amd.com Cc: Aurabindo Pillai aurabindo.pillai@amd.com Cc: Harry Wentland harry.wentland@amd.com Cc: Hamza Mahfooz hamza.mahfooz@amd.com Signed-off-by: Srinivasan Shanmugam srinivasan.shanmugam@amd.com Reviewed-by: Alex Hung alex.hung@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c b/drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c index 2c50c0f745a0b..324e77ceaf1cf 100644 --- a/drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c +++ b/drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c @@ -222,7 +222,7 @@ void dcn401_init_hw(struct dc *dc) uint32_t backlight = MAX_BACKLIGHT_LEVEL; uint32_t user_level = MAX_BACKLIGHT_LEVEL;
- if (dc->clk_mgr && dc->clk_mgr->funcs->init_clocks) { + if (dc->clk_mgr && dc->clk_mgr->funcs && dc->clk_mgr->funcs->init_clocks) { dc->clk_mgr->funcs->init_clocks(dc->clk_mgr);
// mark dcmode limits present if any clock has distinct AC and DC values from SMU @@ -413,7 +413,7 @@ void dcn401_init_hw(struct dc *dc) if (!dcb->funcs->is_accelerated_mode(dcb) && dc->res_pool->hubbub->funcs->init_watermarks) dc->res_pool->hubbub->funcs->init_watermarks(dc->res_pool->hubbub);
- if (dc->clk_mgr->funcs->notify_wm_ranges) + if (dc->clk_mgr && dc->clk_mgr->funcs && dc->clk_mgr->funcs->notify_wm_ranges) dc->clk_mgr->funcs->notify_wm_ranges(dc->clk_mgr);
if (dc->clk_mgr->funcs->set_hard_max_memclk && !dc->clk_mgr->dc_mode_softmax_enabled) @@ -438,7 +438,9 @@ void dcn401_init_hw(struct dc *dc) dc->debug.fams2_config.bits.enable &= dc->ctx->dmub_srv->dmub->feature_caps.fw_assisted_mclk_switch_ver == 2; if (!dc->debug.fams2_config.bits.enable && dc->res_pool->funcs->update_bw_bounding_box) { /* update bounding box if FAMS2 disabled */ - dc->res_pool->funcs->update_bw_bounding_box(dc, dc->clk_mgr->bw_params); + if (dc->clk_mgr) + dc->res_pool->funcs->update_bw_bounding_box(dc, + dc->clk_mgr->bw_params); } } }