From: Dan Carpenter <error27@gmail.com>
To: Dominik Kaszewski <dominik.kaszewski@amd.com>
Cc: amd-gfx@lists.freedesktop.org, "SHANMUGAM,
SRINIVASAN" <SRINIVASAN.SHANMUGAM@amd.com>
Subject: [bug report] drm/amd/display: Remove sink usage from DPMS
Date: Tue, 15 Sep 2026 19:38:46 +0300 [thread overview]
Message-ID: <aql0litI1KOTQNLk@stanley.mountain> (raw)
Hello Dominik Kaszewski,
Commit 8fa813b7fd1e ("drm/amd/display: Remove sink usage from DPMS")
from Jun 19, 2026 (linux-next), leads to the following Smatch static
checker warning:
drivers/gpu/drm/amd/amdgpu/../display/dc/link/link_dpms.c:2423 link_set_dpms_off()
error: we previously assumed 'stream->sink' could be null (see line 2412)
drivers/gpu/drm/amd/amdgpu/../display/dc/link/link_dpms.c
2386 enum dc_status link_set_dpms_off(struct pipe_ctx *pipe_ctx)
2387 {
2388 DC_LOGGER_INIT(pipe_ctx->stream->ctx->logger);
2389 struct dc_stream_state *stream = pipe_ctx->stream;
2390 struct dc *dc = stream->ctx->dc;
2391 struct dc_link *link = stream->link;
2392 struct vpg *vpg = get_vpg(pipe_ctx);
2393 enum dp_panel_mode panel_mode_dp = dp_get_panel_mode(link);
2394
2395 ASSERT(is_master_pipe_for_link(link, pipe_ctx));
2396
2397 if (dc_is_virtual_signal(stream->signal))
2398 /* No real hardware to program for virtual signals. */
2399 return DC_DPMS_SKIPPED_HANDSHAKE;
2400
2401 if (stream->sink) {
^^^^^^^^^^^^
2402 if (stream->sink->sink_signal != SIGNAL_TYPE_VIRTUAL &&
2403 stream->sink->sink_signal != SIGNAL_TYPE_NONE) {
2404 DC_LOG_DC("%s pipe_ctx dispname=%s signal=%x link=%d sink_count=%d\n", __func__,
2405 stream->sink->edid_caps.display_name,
2406 stream->signal, link->link_index, link->sink_count);
2407 }
2408 }
2409
2410 link_wait_for_unlocked(link);
2411
2412 if (stream->sink && !stream->sink->edid_caps.panel_patch.skip_avmute) {
^^^^^^^^^^^^
These places check for NULL
2413 if (dc_is_hdmi_signal(stream->signal))
2414 set_avmute(pipe_ctx, true);
2415 }
2416
2417 dc->hwss.disable_audio_stream(pipe_ctx);
2418
2419 update_psp_stream_config(pipe_ctx, true);
2420 dc->hwss.blank_stream(pipe_ctx);
2421
2422 if (pipe_ctx->link_config.dp_tunnel_settings.should_use_dp_bw_allocation)
--> 2423 deallocate_usb4_bandwidth(stream);
^^^^^^
But here stream->sink is dereferenced without checking.
2424
2425 if (stream->signal == SIGNAL_TYPE_DISPLAY_PORT_MST)
2426 deallocate_mst_payload(pipe_ctx);
2427 else if (dc_is_dp_sst_signal(stream->signal) &&
This email is a free service from the Smatch-CI project [smatch.sf.net].
regards,
dan carpenter
reply other threads:[~2026-09-15 21:01 UTC|newest]
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