Re: [PATCH v3 04/13] drm/edid: abstract debugfs override EDID set/reset

On Wed, Jun 22, 2022 at 01:59:18PM +0300, Jani Nikula wrote:

Add functions drm_edid_override_set() and drm_edid_override_reset() to support "edid_override" connector debugfs, and to hide the details about it in drm_edid.c. No functional changes at this time.

Also note in the connector.override_edid flag kernel-doc that this is only supposed to be modified by the code doing debugfs EDID override handling. Currently, it is still being modified by amdgpu in create_eml_sink() and handle_edid_mgmt() for reasons unknown. This was added in commit 4562236b3bc0 ("drm/amd/dc: Add dc display driver (v2)") and later moved to amdgpu_dm.c in commit e7b07ceef2a6 ("drm/amd/display: Merge amdgpu_dm_types and amdgpu_dm").

Signed-off-by: Jani Nikula jani.nikula@intel.com

Reviewed-by: Ville Syrjälä ville.syrjala@linux.intel.com

---

drivers/gpu/drm/drm_crtc_internal.h | 2 ++ drivers/gpu/drm/drm_debugfs.c | 21 +++++---------------- drivers/gpu/drm/drm_edid.c | 26 ++++++++++++++++++++++++++ include/drm/drm_connector.h | 6 +++++- 4 files changed, 38 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/drm_crtc_internal.h b/drivers/gpu/drm/drm_crtc_internal.h index aecab5308bae..56041b604881 100644 --- a/drivers/gpu/drm/drm_crtc_internal.h +++ b/drivers/gpu/drm/drm_crtc_internal.h @@ -286,3 +286,5 @@ int drm_mode_page_flip_ioctl(struct drm_device *dev,

/* drm_edid.c */ void drm_mode_fixup_1366x768(struct drm_display_mode *mode); +int drm_edid_override_set(struct drm_connector *connector, const void *edid, size_t size); +int drm_edid_override_reset(struct drm_connector *connector); diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c index fb04b7a984de..493922069c90 100644 --- a/drivers/gpu/drm/drm_debugfs.c +++ b/drivers/gpu/drm/drm_debugfs.c @@ -350,31 +350,20 @@ static ssize_t edid_write(struct file *file, const char __user *ubuf, struct seq_file *m = file->private_data; struct drm_connector *connector = m->private; char *buf;

• struct edid *edid; int ret;

  buf = memdup_user(ubuf, len); if (IS_ERR(buf)) return PTR_ERR(buf);

• edid = (struct edid *) buf;

• if (len == 5 && !strncmp(buf, "reset", 5)) {

• connector->override_edid = false;
  

• ret = drm_connector_update_edid_property(connector, NULL);
  

• } else if (len < EDID_LENGTH ||

•    EDID_LENGTH * (1 + edid->extensions) > len)
  

• ret = -EINVAL;
  

• else {

• connector->override_edid = false;
  

• ret = drm_connector_update_edid_property(connector, edid);
  

• if (!ret)
  

• 	connector->override_edid = true;
  

• }

• if (len == 5 && !strncmp(buf, "reset", 5))

• ret = drm_edid_override_reset(connector);
  

• else

• ret = drm_edid_override_set(connector, buf, len);
  
  

  kfree(buf);

• return (ret) ? ret : len;

• return ret ? ret : len;

}

/* diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index e360e1a269f4..c3f0f0a5a8a9 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -2161,6 +2161,32 @@ static struct edid *drm_get_override_edid(struct drm_connector *connector, return IS_ERR(override) ? NULL : override; }

+/* For debugfs edid_override implementation */ +int drm_edid_override_set(struct drm_connector *connector, const void *edid,

• 	  size_t size)
  

+{

• int ret;
• if (size < EDID_LENGTH || edid_size(edid) > size)

• return -EINVAL;
  

• connector->override_edid = false;
• ret = drm_connector_update_edid_property(connector, edid);
• if (!ret)

• connector->override_edid = true;
  

• return ret;

+}

+/* For debugfs edid_override implementation */ +int drm_edid_override_reset(struct drm_connector *connector) +{

• connector->override_edid = false;
• return drm_connector_update_edid_property(connector, NULL);

+}

/**

• drm_add_override_edid_modes - add modes from override/firmware EDID
• @connector: connector we're probing

diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h index 94b422b55cc1..a1705d6b3fba 100644 --- a/include/drm/drm_connector.h +++ b/include/drm/drm_connector.h @@ -1527,7 +1527,11 @@ struct drm_connector { struct drm_cmdline_mode cmdline_mode; /** @force: a DRM_FORCE_<foo> state for forced mode sets */ enum drm_connector_force force;

• /** @override_edid: has the EDID been overwritten through debugfs for testing? */

• /**

• * @override_edid: has the EDID been overwritten through debugfs for
  

• * testing? Do not modify outside of drm_edid_override_set() and
  

• * drm_edid_override_reset().
  

• */
  

  bool override_edid; /** @epoch_counter: used to detect any other changes in connector, besides status */ u64 epoch_counter;

-- 2.30.2