drm/amd/display: on dp link lost event toggle dpms for master pipe only

[why]
We mistakenly toggle dpms state for non master pipe when handling
link lost. A non master pipe doesn't connect to a backend. So it is
toggling dpms for non master is undefined and caused NULL pointer
dereference.

[how]
Add helper functions to find an array of active master pipes for current
link and only toggle DPMS for active master pipes connected to the link.
Add assert in case we get called to program dpms with non master pipe.

Reviewed-by: Alvin Lee <Alvin.Lee2@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/dc/link/accessories/link_dp_cts.c b/drivers/gpu/drm/amd/display/dc/link/accessories/link_dp_cts.c
index 769b782a9b841b4ef699a237c8fae2aba3f1d88c..ee290ec247de56906aab6160467a9f1508acf75f 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/link/accessories/link_dp_cts.c
+++ b/drivers/gpu/drm/amd/display/dc/link/accessories/link_dp_cts.c
@@ -27,6 +27,7 @@
 #include "link/protocols/link_dp_training.h"
 #include "link/protocols/link_dp_phy.h"
 #include "link/protocols/link_dp_training_fixed_vs_pe_retimer.h"
+#include "link/link_dpms.h"
 #include "resource.h"
 #include "dm_helpers.h"
 #include "dc_dmub_srv.h"
@@ -77,37 +78,26 @@ void dp_retrain_link_dp_test(struct dc_link *link,
                        struct dc_link_settings *link_setting,
                        bool skip_video_pattern)
 {
-       struct pipe_ctx *pipe;
-       unsigned int i;
+       struct pipe_ctx *pipes[MAX_PIPES];
+       struct dc_state *state = link->dc->current_state;
+       uint8_t count;
+       int i;
 
        udelay(100);
 
-       for (i = 0; i < MAX_PIPES; i++) {
-               pipe = &link->dc->current_state->res_ctx.pipe_ctx[i];
-               if (pipe->stream != NULL &&
-                               pipe->stream->link == link &&
-                               !pipe->stream->dpms_off &&
-                               !pipe->top_pipe && !pipe->prev_odm_pipe) {
-                       link_set_dpms_off(pipe);
-                       pipe->link_config.dp_link_settings = *link_setting;
-                       update_dp_encoder_resources_for_test_harness(
-                                       link->dc,
-                                       pipe->stream->ctx->dc->current_state,
-                                       pipe);
-               }
-       }
+       link_get_master_pipes_with_dpms_on(link, state, &count, pipes);
 
-       for (i = 0; i < MAX_PIPES; i++) {
-               pipe = &link->dc->current_state->res_ctx.pipe_ctx[i];
-               if (pipe->stream != NULL &&
-                               pipe->stream->link == link &&
-                               !pipe->stream->dpms_off &&
-                               !pipe->top_pipe && !pipe->prev_odm_pipe) {
-                       link_set_dpms_on(
-                                       pipe->stream->ctx->dc->current_state,
-                                       pipe);
-               }
+       for (i = 0; i < count; i++) {
+               link_set_dpms_off(pipes[i]);
+               pipes[i]->link_config.dp_link_settings = *link_setting;
+               update_dp_encoder_resources_for_test_harness(
+                               link->dc,
+                               state,
+                               pipes[i]);
        }
+
+       for (i = count-1; i >= 0; i--)
+               link_set_dpms_on(state, pipes[i]);
 }
 
 static void dp_test_send_link_training(struct dc_link *link)

diff --git a/drivers/gpu/drm/amd/display/dc/link/link_detection.c b/drivers/gpu/drm/amd/display/dc/link/link_detection.c
index 63e75c392031cae88c5079afcf70df34364a9ebf..001a4ac9bfcf1d4644679f476cfb2e3958c5aaf7 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/link/link_detection.c
+++ b/drivers/gpu/drm/amd/display/dc/link/link_detection.c
@@ -30,6 +30,7 @@
  * directly from connected receivers.
  */
 
+#include "link_dpms.h"
 #include "link_detection.h"
 #include "link_hwss.h"
 #include "protocols/link_edp_panel_control.h"
@@ -755,34 +756,6 @@ static void restore_phy_clocks_for_destructive_link_verification(const struct dc
        clk_mgr_optimize_pwr_state(dc, dc->clk_mgr);
 }
 
-static void set_all_streams_dpms_off_for_link(struct dc_link *link)
-{
-       int i;
-       struct pipe_ctx *pipe_ctx;
-       struct dc_stream_update stream_update;
-       bool dpms_off = true;
-       struct link_resource link_res = {0};
-
-       memset(&stream_update, 0, sizeof(stream_update));
-       stream_update.dpms_off = &dpms_off;
-
-       for (i = 0; i < MAX_PIPES; i++) {
-               pipe_ctx = &link->dc->current_state->res_ctx.pipe_ctx[i];
-               if (pipe_ctx && pipe_ctx->stream && !pipe_ctx->stream->dpms_off &&
-                               pipe_ctx->stream->link == link && !pipe_ctx->prev_odm_pipe) {
-                       stream_update.stream = pipe_ctx->stream;
-                       dc_commit_updates_for_stream(link->ctx->dc, NULL, 0,
-                                       pipe_ctx->stream, &stream_update,
-                                       link->ctx->dc->current_state);
-               }
-       }
-
-       /* link can be also enabled by vbios. In this case it is not recorded
-        * in pipe_ctx. Disable link phy here to make sure it is completely off
-        */
-       dp_disable_link_phy(link, &link_res, link->connector_signal);
-}
-
 static void verify_link_capability_destructive(struct dc_link *link,
                struct dc_sink *sink,
                enum dc_detect_reason reason)
@@ -796,7 +769,7 @@ static void verify_link_capability_destructive(struct dc_link *link,
        if (dc_is_dp_signal(link->local_sink->sink_signal)) {
                struct dc_link_settings known_limit_link_setting =
                                dp_get_max_link_cap(link);
-               set_all_streams_dpms_off_for_link(link);
+               link_set_all_streams_dpms_off_for_link(link);
                dp_verify_link_cap_with_retries(
                                link, &known_limit_link_setting,
                                LINK_TRAINING_MAX_VERIFY_RETRY);

diff --git a/drivers/gpu/drm/amd/display/dc/link/link_dpms.c b/drivers/gpu/drm/amd/display/dc/link/link_dpms.c
index 618fd552cb3d374dad4ac26cb9fa07ef42581e7c..026683ce24a436f0e48e42eda38d2b7376db6211 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/link/link_dpms.c
+++ b/drivers/gpu/drm/amd/display/dc/link/link_dpms.c
@@ -140,12 +140,76 @@ void link_blank_dp_stream(struct dc_link *link, bool hw_init)
        }
 }
 
+void link_set_all_streams_dpms_off_for_link(struct dc_link *link)
+{
+       struct pipe_ctx *pipes[MAX_PIPES];
+       struct dc_state *state = link->dc->current_state;
+       uint8_t count;
+       int i;
+       struct dc_stream_update stream_update;
+       bool dpms_off = true;
+       struct link_resource link_res = {0};
+
+       memset(&stream_update, 0, sizeof(stream_update));
+       stream_update.dpms_off = &dpms_off;
+
+       link_get_master_pipes_with_dpms_on(link, state, &count, pipes);
+
+       for (i = 0; i < count; i++) {
+               stream_update.stream = pipes[i]->stream;
+               dc_commit_updates_for_stream(link->ctx->dc, NULL, 0,
+                               pipes[i]->stream, &stream_update,
+                               state);
+       }
+
+       /* link can be also enabled by vbios. In this case it is not recorded
+        * in pipe_ctx. Disable link phy here to make sure it is completely off
+        */
+       dp_disable_link_phy(link, &link_res, link->connector_signal);
+}
+
 void link_resume(struct dc_link *link)
 {
        if (link->connector_signal != SIGNAL_TYPE_VIRTUAL)
                program_hpd_filter(link);
 }
 
+/* This function returns true if the pipe is used to feed video signal directly
+ * to the link.
+ */
+static bool is_master_pipe_for_link(const struct dc_link *link,
+               const struct pipe_ctx *pipe)
+{
+       return (pipe->stream &&
+                       pipe->stream->link &&
+                       pipe->stream->link == link &&
+                       pipe->top_pipe == NULL &&
+                       pipe->prev_odm_pipe == NULL);
+}
+
+/*
+ * This function finds all master pipes feeding to a given link with dpms set to
+ * on in given dc state.
+ */
+void link_get_master_pipes_with_dpms_on(const struct dc_link *link,
+               struct dc_state *state,
+               uint8_t *count,
+               struct pipe_ctx *pipes[MAX_PIPES])
+{
+       int i;
+       struct pipe_ctx *pipe = NULL;
+
+       *count = 0;
+       for (i = 0; i < MAX_PIPES; i++) {
+               pipe = &state->res_ctx.pipe_ctx[i];
+
+               if (is_master_pipe_for_link(link, pipe) &&
+                               pipe->stream->dpms_off == false) {
+                       pipes[(*count)++] = pipe;
+               }
+       }
+}
+
 static bool get_ext_hdmi_settings(struct pipe_ctx *pipe_ctx,
                enum engine_id eng_id,
                struct ext_hdmi_settings *settings)
@@ -2176,6 +2240,8 @@ void link_set_dpms_off(struct pipe_ctx *pipe_ctx)
        struct dc_link *link = stream->sink->link;
        struct vpg *vpg = pipe_ctx->stream_res.stream_enc->vpg;
 
+       ASSERT(is_master_pipe_for_link(link, pipe_ctx));
+
        if (link_is_dp_128b_132b_signal(pipe_ctx))
                vpg = pipe_ctx->stream_res.hpo_dp_stream_enc->vpg;
 
@@ -2280,6 +2346,8 @@ void link_set_dpms_on(
        struct vpg *vpg = pipe_ctx->stream_res.stream_enc->vpg;
        const struct link_hwss *link_hwss = get_link_hwss(link, &pipe_ctx->link_res);
 
+       ASSERT(is_master_pipe_for_link(link, pipe_ctx));
+
        if (link_is_dp_128b_132b_signal(pipe_ctx))
                vpg = pipe_ctx->stream_res.hpo_dp_stream_enc->vpg;
 
@@ -2463,4 +2531,3 @@ void link_set_dpms_on(
                set_avmute(pipe_ctx, false);
        }
 }
-

diff --git a/drivers/gpu/drm/amd/display/dc/link/link_dpms.h b/drivers/gpu/drm/amd/display/dc/link/link_dpms.h
index 7ce0124ed7d11d8f42906a7cc55c1e118b2f9995..33d312dabdb8b32de56e6f38ad5807088e4837db 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/link/link_dpms.h
+++ b/drivers/gpu/drm/amd/display/dc/link/link_dpms.h
@@ -32,4 +32,9 @@ bool link_set_dsc_pps_packet(struct pipe_ctx *pipe_ctx,
 struct fixed31_32 link_calculate_sst_avg_time_slots_per_mtp(
                const struct dc_stream_state *stream,
                const struct dc_link *link);
+void link_set_all_streams_dpms_off_for_link(struct dc_link *link);
+void link_get_master_pipes_with_dpms_on(const struct dc_link *link,
+               struct dc_state *state,
+               uint8_t *count,
+               struct pipe_ctx *pipes[MAX_PIPES]);
 #endif /* __DC_LINK_DPMS_H__ */

diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_irq_handler.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_irq_handler.c
index eff23b7b324a332b8eba48e064d58c0475c6545c..9d80427520cf401ee10edd2a07e11ac9ca55acfe 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_irq_handler.c
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_irq_handler.c
@@ -34,6 +34,7 @@
 #include "link_dp_training.h"
 #include "link_dp_capability.h"
 #include "link/accessories/link_dp_trace.h"
+#include "link/link_dpms.h"
 #include "dm_helpers.h"
 
 #define DC_LOGGER_INIT(logger)
@@ -175,40 +176,27 @@ static bool handle_hpd_irq_psr_sink(struct dc_link *link)
 
 void dc_link_dp_handle_link_loss(struct dc_link *link)
 {
+       struct pipe_ctx *pipes[MAX_PIPES];
+       struct dc_state *state = link->dc->current_state;
+       uint8_t count;
        int i;
-       struct pipe_ctx *pipe_ctx;
 
-       for (i = 0; i < MAX_PIPES; i++) {
-               pipe_ctx = &link->dc->current_state->res_ctx.pipe_ctx[i];
-               if (pipe_ctx && pipe_ctx->stream && pipe_ctx->stream->link == link)
-                       break;
-       }
+       link_get_master_pipes_with_dpms_on(link, state, &count, pipes);
 
-       if (pipe_ctx == NULL || pipe_ctx->stream == NULL)
-               return;
+       for (i = 0; i < count; i++)
+               link_set_dpms_off(pipes[i]);
 
-       for (i = 0; i < MAX_PIPES; i++) {
-               pipe_ctx = &link->dc->current_state->res_ctx.pipe_ctx[i];
-               if (pipe_ctx && pipe_ctx->stream && !pipe_ctx->stream->dpms_off &&
-                               pipe_ctx->stream->link == link && !pipe_ctx->prev_odm_pipe)
-                       link_set_dpms_off(pipe_ctx);
-       }
-
-       for (i = 0; i < MAX_PIPES; i++) {
-               pipe_ctx = &link->dc->current_state->res_ctx.pipe_ctx[i];
-               if (pipe_ctx && pipe_ctx->stream && !pipe_ctx->stream->dpms_off
-                               && pipe_ctx->stream->link == link && !pipe_ctx->prev_odm_pipe) {
-                       // Always use max settings here for DP 1.4a LL Compliance CTS
-                       if (link->is_automated) {
-                               pipe_ctx->link_config.dp_link_settings.lane_count =
-                                               link->verified_link_cap.lane_count;
-                               pipe_ctx->link_config.dp_link_settings.link_rate =
-                                               link->verified_link_cap.link_rate;
-                               pipe_ctx->link_config.dp_link_settings.link_spread =
-                                               link->verified_link_cap.link_spread;
-                       }
-                       link_set_dpms_on(link->dc->current_state, pipe_ctx);
+       for (i = count - 1; i >= 0; i--) {
+               // Always use max settings here for DP 1.4a LL Compliance CTS
+               if (link->is_automated) {
+                       pipes[i]->link_config.dp_link_settings.lane_count =
+                                       link->verified_link_cap.lane_count;
+                       pipes[i]->link_config.dp_link_settings.link_rate =
+                                       link->verified_link_cap.link_rate;
+                       pipes[i]->link_config.dp_link_settings.link_spread =
+                                       link->verified_link_cap.link_spread;
                }
+               link_set_dpms_on(link->dc->current_state, pipes[i]);
        }
 }