Re: [PATCH 03/13] drm/amd/display: parse display name from drm_eld

[Melissa Wen]

On 14/04/2025 07:10, Jani Nikula wrote:

On Fri, 11 Apr 2025, Melissa Wen <m...@igalia.com> wrote:

We don't need to parse dc_edid to get the display name since it's
already set in drm_eld which in turn had it values updated when updating
connector with the opaque drm_edid.

Signed-off-by: Melissa Wen <m...@igalia.com>
---
  .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c  | 10 ++++++----
  1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c 
b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
index e93adb7e48a5..faea6b7fb3f3 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
@@ -34,7 +34,7 @@
  #include <drm/amdgpu_drm.h>
  #include <drm/drm_edid.h>
  #include <drm/drm_fixed.h>
-
+#include <drm/drm_eld.h>
  #include "dm_services.h"
  #include "amdgpu.h"
  #include "dc.h"
@@ -90,6 +90,7 @@ static void apply_edid_quirks(struct drm_device *dev, struct 
edid *edid, struct
        }
  }

+#define AMDGPU_ELD_DISPLAY_NAME_SIZE_IN_CHARS 13

  /**
   * dm_helpers_parse_edid_caps() - Parse edid caps
   *
@@ -132,9 +133,10 @@ enum dc_edid_status dm_helpers_parse_edid_caps(
        edid_caps->manufacture_week = product_id.week_of_manufacture;
        edid_caps->manufacture_year = product_id.year_of_manufacture;

- drm_edid_get_monitor_name(edid_buf,

-                                 edid_caps->display_name,
-                                 AUDIO_INFO_DISPLAY_NAME_SIZE_IN_CHARS);
+       memset(edid_caps->display_name, 0, 
AUDIO_INFO_DISPLAY_NAME_SIZE_IN_CHARS);
+       memcpy(edid_caps->display_name,
+              &connector->eld[DRM_ELD_MONITOR_NAME_STRING],
+              AMDGPU_ELD_DISPLAY_NAME_SIZE_IN_CHARS);

It's not that simple. The monitor name in ELD is not fixed length (see
drm_eld_mnl()) and neither is it guaranteed to be NUL terminated.

I see. Thanks for raising these points.
I need to looking for a better solution then.

Melissa

BR,
Jani.

edid_caps->edid_hdmi = connector->display_info.is_hdmi;