drm/amd/display: Make DMCUB tracebuffer debugfs chronological

[Why]

Previously, the debugfs did a simple dump of the tracebuffer region.
Because the tracebuffer is a ring, it meant that the entries printed may
not be in chronological order if the ring rolled over. This makes
parsing the tracelog cumbersome.

[How]

Since dmcub provides the current entry count, use that to determine
the latest tracelog entry and output the log chronologically.

Also, the fb region size is not accurate of the actual tracebuffer size;
it has been padded to alignment requirements. Use the tracebuffer size
reported by the fw meta_info, if available. If not, a fallback to the
hardcoded default is needed. To make this value available to other .c
files, its define was moved to dmub_srv.h.

Also, print a indicator at the start of the log if rollover occurred.

Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Aurabindo Pillai <aurabindo.pillai@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/amdgpu_dm/amdgpu_dm_debugfs.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
index 6a97bb2d9160155301b028af882b4d9eea30c323..11a7ac54f91c613662e77658fa046ea6c1b2451b 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
@@ -902,9 +902,10 @@ static int dmub_tracebuffer_show(struct seq_file *m, void *data)
 {
        struct amdgpu_device *adev = m->private;
        struct dmub_srv_fb_info *fb_info = adev->dm.dmub_fb_info;
+       struct dmub_fw_meta_info *fw_meta_info = &adev->dm.dmub_srv->meta_info;
        struct dmub_debugfs_trace_entry *entries;
        uint8_t *tbuf_base;
-       uint32_t tbuf_size, max_entries, num_entries, i;
+       uint32_t tbuf_size, max_entries, num_entries, first_entry, i;
 
        if (!fb_info)
                return 0;
@@ -913,20 +914,39 @@ static int dmub_tracebuffer_show(struct seq_file *m, void *data)
        if (!tbuf_base)
                return 0;
 
-       tbuf_size = fb_info->fb[DMUB_WINDOW_5_TRACEBUFF].size;
+       tbuf_size = fw_meta_info ? fw_meta_info->trace_buffer_size :
+                                  DMUB_TRACE_BUFFER_SIZE;
        max_entries = (tbuf_size - sizeof(struct dmub_debugfs_trace_header)) /
                      sizeof(struct dmub_debugfs_trace_entry);
 
        num_entries =
                ((struct dmub_debugfs_trace_header *)tbuf_base)->entry_count;
 
+       /* DMCUB tracebuffer is a ring. If it rolled over, print a hint that
+        * entries are being overwritten.
+        */
+       if (num_entries > max_entries)
+               seq_printf(m, "...\n");
+
+       first_entry = num_entries % max_entries;
        num_entries = min(num_entries, max_entries);
 
        entries = (struct dmub_debugfs_trace_entry
                           *)(tbuf_base +
                              sizeof(struct dmub_debugfs_trace_header));
 
-       for (i = 0; i < num_entries; ++i) {
+       /* To print entries chronologically, start from the first entry till the
+        * top of buffer, then from base of buffer to first entry.
+        */
+       for (i = first_entry; i < num_entries; ++i) {
+               struct dmub_debugfs_trace_entry *entry = &entries[i];
+
+               seq_printf(m,
+                          "trace_code=%u tick_count=%u param0=%u param1=%u\n",
+                          entry->trace_code, entry->tick_count, entry->param0,
+                          entry->param1);
+       }
+       for (i = 0; i < first_entry; ++i) {
                struct dmub_debugfs_trace_entry *entry = &entries[i];
 
                seq_printf(m,

diff --git a/drivers/gpu/drm/amd/display/dmub/dmub_srv.h b/drivers/gpu/drm/amd/display/dmub/dmub_srv.h
index b353c4ceb60dce88dbe86c3bec1535104682b792..4b3ccbca0da2724bc533c3791c2e949b72c9b31f 100644 (file)
--- a/drivers/gpu/drm/amd/display/dmub/dmub_srv.h
+++ b/drivers/gpu/drm/amd/display/dmub/dmub_srv.h
@@ -69,6 +69,9 @@
 
 #define DMUB_PC_SNAPSHOT_COUNT 10
 
+/* Default tracebuffer size if meta is absent. */
+#define DMUB_TRACE_BUFFER_SIZE (64 * 1024)
+
 /* Forward declarations */
 struct dmub_srv;
 struct dmub_srv_common_regs;

diff --git a/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c b/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c
index a3f3ff5d49ace06726b517fba87e94d3e846ab93..15ea216e903d587125f70221363a24926607f5b0 100644 (file)
--- a/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c
+++ b/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c
@@ -61,10 +61,6 @@
 /* Default state size if meta is absent. */
 #define DMUB_FW_STATE_SIZE (64 * 1024)
 
-/* Default tracebuffer size if meta is absent. */
-#define DMUB_TRACE_BUFFER_SIZE (64 * 1024)
-
-
 /* Default scratch mem size. */
 #define DMUB_SCRATCH_MEM_SIZE (1024)