Re: [PATCH 16/32] drm/amd/display: Add Support for HDMI Compliance Automation

On Wednesday, 10 June 2026 16:43:37 Central European Summer Time Nicolas Frattaroli wrote:
> On Wednesday, 10 June 2026 11:45:00 Central European Summer Time Chenyu Chen wrote:
> > From: Fangzhi Zuo <[email protected]>
> > 
> > Add support to get DUT trained at FRL link rate when working with
> > Teledyne M41h compliance automation.
> > 
> > Reviewed-by: Alex Hung <[email protected]>
> > Signed-off-by: Fangzhi Zuo <[email protected]>
> > Signed-off-by: Chenyu Chen <[email protected]>
> > ---
> >  .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h |  3 +
> >  .../display/amdgpu_dm/amdgpu_dm_connector.c   |  5 ++
> >  .../amd/display/amdgpu_dm/amdgpu_dm_debugfs.c | 67 ++++++++++++++++++-
> >  .../amd/display/amdgpu_dm/amdgpu_dm_helpers.c |  6 ++
> >  4 files changed, 80 insertions(+), 1 deletion(-)
> > 
> > [... snip ...]
> > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
> > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
> > @@ -2982,6 +2982,64 @@ static ssize_t hdmi_cec_state_write(struct file *f, const char __user *buf,
> >  	return size;
> >  }
> >  
> > +/**
> > + * hdmi_automation_enable - Enable/Disable HDMI automation feature
> > + * @f: file structure.
> > + * @buf: userspace buffer. set to '1' to enable; '0' to disable automation feature.
> > + * @size: size of buffer from userpsace.
> > + * @pos: unused.
> > + *
> > + * Return size on success, error code on failure
> > + */
> > +static ssize_t hdmi_automation_enable(struct file *f, const char __user *buf,
> > +	size_t size, loff_t *pos)
> > +{
> > +	struct amdgpu_dm_connector *aconnector = file_inode(f)->i_private;
> > +	char *wr_buf = NULL;
> > +	const uint32_t wr_buf_size = 40;
> > +	int max_param_num = 1;
> > +	uint8_t param_nums = 0;
> > +	long param[2];
> > +	bool hdmi_comp_auto;
> > +
> > +	if (size == 0)
> > +		return -EINVAL;
> > +
> > +	wr_buf = kcalloc(wr_buf_size, sizeof(char), GFP_KERNEL);
> > +	if (!wr_buf)
> > +		return -ENOSPC;
> > +
> > +	if (parse_write_buffer_into_params(wr_buf, wr_buf_size,
> > +					   (long *)param, buf,
> > +					   max_param_num,
> > +					   &param_nums)) {
> > +		kfree(wr_buf);
> > +		return -EINVAL;
> > +	}
> > +
> > +	if (param_nums <= 0) {
> > +		kfree(wr_buf);
> > +		DRM_DEBUG_DRIVER("user data not be read\n");
> > +		return -EINVAL;
> > +	}
> > +
> > +	switch (param[0]) {
> > +	case 0:
> > +		hdmi_comp_auto = false;
> > +		break;
> > +	case 1:
> > +	default:
> > +		hdmi_comp_auto = true;
> > +		break;
> > +	}
> > +
> > +	/* Persist setting across sink re-detection/hotplug. */
> > +	aconnector->hdmi_comp_auto = hdmi_comp_auto;
> > +
> > +	kfree(wr_buf);
> > +	return size;
> > +}
> > +
> >  DEFINE_SHOW_ATTRIBUTE(dp_dsc_fec_support);
> >  DEFINE_SHOW_ATTRIBUTE(dmub_fw_state);
> >  DEFINE_SHOW_ATTRIBUTE(dmub_tracebuffer);
> > @@ -3099,6 +3157,12 @@ static const struct file_operations dp_mst_link_settings_debugfs_fops = {
> >  	.llseek = default_llseek
> >  };
> >  
> > +static const struct file_operations hdmi_automation_debugfs_fops = {
> > +	.owner = THIS_MODULE,
> > +	.write = hdmi_automation_enable,
> > +	.llseek = default_llseek
> > +};
> > +
> 
> I really don't understand why this can't just be a DEFINE_DEBUGFS_ATTRIBUTE,
> and then you can replace the overcomplicated hdmi_automation_enable() with
> just simple setter and getter functions that already receive the parameter
> of the right type.

Aaaand this was applied without the review comment being addressed.

Along with the incredible other things in this series, like

   link.dpcd_caps.dongle_type = (typeof(link.dpcd_caps.dongle_type))0x7f;

in "[PATCH 21/32] drm/amd/display: Add KUnit tests for amdgpu_dm_connector",
I'm feeling like AMD is treating mainline as a vendor BSP to just dump code
into.

> >  static const struct {
> >  	char *name;
> >  	const struct file_operations *fops;
> > @@ -3131,7 +3195,8 @@ static const struct {
> >  	const struct file_operations *fops;
> >  } hdmi_debugfs_entries[] = {
> >  		{"hdcp_sink_capability", &hdcp_sink_capability_fops},
> > -		{"hdmi_cec_state", &hdmi_cec_state_fops}
> > +		{"hdmi_cec_state", &hdmi_cec_state_fops},
> > +		{"hdmi_automation", &hdmi_automation_debugfs_fops}
> >  };
> >  
> >  /*
> > 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 a2d0bb34e639..6350212b9a66 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
> > @@ -193,6 +193,12 @@ enum dc_edid_status dm_helpers_parse_edid_caps(
> >  					__func__, connector->name, edid_caps->frl_dsc_10bpc, edid_caps->frl_dsc_12bpc, \
> >  					edid_caps->frl_dsc_all_bpp, edid_caps->frl_dsc_native_420, edid_caps->frl_dsc_max_slices, \
> >  					edid_caps->frl_dsc_max_frl_rate, edid_caps->frl_dsc_total_chunk_kbytes);
> > +		if (aconnector->hdmi_comp_auto) {
> > +			edid_caps->panel_patch.hdmi_comp_auto = true;
> > +			link->ctx->dc->debug.force_frl_max = true;
> > +			link->ctx->dc->debug.force_frl_dsc = true;
> > +			drm_dbg_driver(connector->dev, "%s: HDMI_FRL [%s] hdmi_comp_auto --> enabled\n", __func__, connector->name);
> > +		}
> >  	}
> >  
> >  	apply_edid_quirks(link, edid_buf, edid_caps);
> > 
> 
>