[RFC 1/5] drm: Add HDMI 2.0+ features exposing knob

[Daniel Vetter]

On Mon, Mar 27, 2017 at 02:47:08PM +0100, Jose Abreu wrote:
> Hi Daniel,
> 
> 
> On 23-03-2017 11:00, Daniel Vetter wrote:
> > On Thu, Mar 23, 2017 at 10:44:16AM +0000, Jose Abreu wrote:
> >> Hi Daniel,
> >>
> >>
> >> On 23-03-2017 07:22, Daniel Vetter wrote:
> >>> On Wed, Mar 22, 2017 at 05:35:57PM +0000, Jose Abreu wrote:
> >>>> We can't expect userspace to have full support for all HDMI 2.0+
> >>>> features. Instead of expecting/waiting for userspace to support
> >>>> the new features add a knob, much like the stereo knob, so that
> >>>> DRM core will only expose the features when asked too.
> >>>>
> >>>> Signed-off-by: Jose Abreu <joabreu at synopsys.com>
> >>>> Cc: Carlos Palminha <palminha at synopsys.com>
> >>>> Cc: dri-devel at lists.freedesktop.org
> >>>> ---
> >>>>  drivers/gpu/drm/drm_ioctl.c | 5 +++++
> >>>>  include/drm/drm_file.h      | 8 ++++++++
> >>>>  include/uapi/drm/drm.h      | 7 +++++++
> >>>>  3 files changed, 20 insertions(+)
> >>>>
> >>>> diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
> >>>> index a7c61c2..2430e2e 100644
> >>>> --- a/drivers/gpu/drm/drm_ioctl.c
> >>>> +++ b/drivers/gpu/drm/drm_ioctl.c
> >>>> @@ -318,6 +318,11 @@ static int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_
> >>>>  		file_priv->atomic = req->value;
> >>>>  		file_priv->universal_planes = req->value;
> >>>>  		break;
> >>>> +	case DRM_CLIENT_CAP_HDMI2:
> >>>> +		if (req->value > 1)
> >>>> +			return -EINVAL;
> >>>> +		file_priv->hdmi2_allowed = req->value;
> >>> Needs some userspace to make use of this (like the -modesetting x.org
> >>> driver).
> >>> -Daniel
> >> I see your point but shouldn't this be merged before actually
> >> starting to work in userspace?
> > No, see
> >
> > https://urldefense.proofpoint.com/v2/url?u=https-3A__dri.freedesktop.org_docs_drm_gpu_drm-2Duapi.html-23open-2Dsource-2Duserspace-2Drequirements&d=DwIBAg&c=DPL6_X_6JkXFx7AXWqB0tg&r=WHDsc6kcWAl4i96Vm5hJ_19IJiuxx_p_Rzo2g-uHDKw&m=tcc2TQFpF7ats3OIzYgmFrHaeymBrPtqHphO4Ui4AUY&s=qWySmgpGaOwxC8Jl3A5qZVf4aS2qz3LXshVdv3FehJc&e= 
> >
> > for reasons behind this and the precise flow.
> >
> > Cheers, Daniel
> 
> Thanks, I will do that. I can leave the flag and just limit the
> export of aspect ratios for now, we can limit more stuff later if
> needed. What do you think?
> 
> Another thing: Is it safe to enable this in the modesetting
> driver, shouldn't the modesetting clients also know about the
> flag or does modesetting handles this correctly? (I'm not very
> familiar with this driver, sorry).

Probably needs an xrandr revision too.
-Daniel

> 
> Best regards,
> Jose Miguel Abreu
> 
> >
> >> Best regards,
> >> Jose Miguel Abreu
> >>
> >>>> +		break;
> >>>>  	default:
> >>>>  		return -EINVAL;
> >>>>  	}
> >>>> diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
> >>>> index 5dd27ae..7b97d85 100644
> >>>> --- a/include/drm/drm_file.h
> >>>> +++ b/include/drm/drm_file.h
> >>>> @@ -192,6 +192,14 @@ struct drm_file {
> >>>>  	unsigned is_master:1;
> >>>>  
> >>>>  	/**
> >>>> +	 * @hdmi2_allowed:
> >>>> +	 *
> >>>> +	 * True if client understands HDMI 2.0+ features like, for example,
> >>>> +	 * extended aspect ratios
> >>>> +	 */
> >>>> +	unsigned hdmi2_allowed:1;
> >>>> +
> >>>> +	/**
> >>>>  	 * @master:
> >>>>  	 *
> >>>>  	 * Master this node is currently associated with. Only relevant if
> >>>> diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
> >>>> index b2c5284..9e25138 100644
> >>>> --- a/include/uapi/drm/drm.h
> >>>> +++ b/include/uapi/drm/drm.h
> >>>> @@ -678,6 +678,13 @@ struct drm_get_cap {
> >>>>   */
> >>>>  #define DRM_CLIENT_CAP_ATOMIC	3
> >>>>  
> >>>> +/**
> >>>> + * DRM_CLIENT_CAP_HDMI2
> >>>> + *
> >>>> + * If set to 1, the DRM core will expose HDMI 2.0+ features to userspace
> >>>> + */
> >>>> +#define DRM_CLIENT_CAP_HDMI2	4
> >>>> +
> >>>>  /** DRM_IOCTL_SET_CLIENT_CAP ioctl argument type */
> >>>>  struct drm_set_client_cap {
> >>>>  	__u64 capability;
> >>>> -- 
> >>>> 1.9.1
> >>>>
> >>>>
> >>>> _______________________________________________
> >>>> dri-devel mailing list
> >>>> dri-devel at lists.freedesktop.org
> >>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__lists.freedesktop.org_mailman_listinfo_dri-2Ddevel&d=DwIBAg&c=DPL6_X_6JkXFx7AXWqB0tg&r=WHDsc6kcWAl4i96Vm5hJ_19IJiuxx_p_Rzo2g-uHDKw&m=4lBpQovdR7O8jeC7mV8SX9xvTypMtV8CBDEDg3bGgzw&s=h-gqFlO62i53pir0j2lJ-upE_bXQxhn3BK1nhdxoB6Y&e= 
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch