[bug report] drm/amd/display: Make DMCUB tracebuffer debugfs chronological

[Dan Carpenter]

Hello Leo Li,

Commit 5a498172c8d0 ("drm/amd/display: Make DMCUB tracebuffer debugfs
chronological") from Nov 26, 2024 (linux-next), leads to the
following Smatch static checker warning:

	drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_debugfs.c:917 dmub_tracebuffer_show()
	warn: address of 'adev->dm.dmub_srv->meta_info' is non-NULL

drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_debugfs.c
    901 static int dmub_tracebuffer_show(struct seq_file *m, void *data)
    902 {
    903         struct amdgpu_device *adev = m->private;
    904         struct dmub_srv_fb_info *fb_info = adev->dm.dmub_fb_info;
    905         struct dmub_fw_meta_info *fw_meta_info = &adev->dm.dmub_srv->meta_info;
                                                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Even if adev->dm.dmub_srv is NULL, the address of ->meta_info can't be NULL

    906         struct dmub_debugfs_trace_entry *entries;
    907         uint8_t *tbuf_base;
    908         uint32_t tbuf_size, max_entries, num_entries, first_entry, i;
    909 
    910         if (!fb_info)
    911                 return 0;
    912 
    913         tbuf_base = (uint8_t *)fb_info->fb[DMUB_WINDOW_5_TRACEBUFF].cpu_addr;
    914         if (!tbuf_base)
    915                 return 0;
    916 
--> 917         tbuf_size = fw_meta_info ? fw_meta_info->trace_buffer_size :
                            ^^^^^^^^^^^^
Always non-NULL

    918                                    DMUB_TRACE_BUFFER_SIZE;
    919         max_entries = (tbuf_size - sizeof(struct dmub_debugfs_trace_header)) /
    920                       sizeof(struct dmub_debugfs_trace_entry);
    921 
    922         num_entries =

regards,
dan carpenter