[PATCH 2/3] drm/bridge: dw-hdmi-qp: Add support for missing HPD

Sebastian Reichel sebastian.reichel at collabora.com
Fri Nov 7 02:08:47 PST 2025


Hi,

On Thu, Nov 06, 2025 at 08:40:55PM +0100, Heiko Stuebner wrote:
> Am Donnerstag, 6. November 2025, 19:09:13 Mitteleuropäische Normalzeit schrieb Chris Morgan:
> > From: Chris Morgan <macromorgan at hotmail.com>
> > 
> > Add support for the dw-hdmi-qp driver to handle devices with missing
> > HPD pins.
> > 
> > Since in this situation we are now polling for the EDID data via i2c
> > change the error message to a debug message when we are unable to
> > complete an i2c read, as a disconnected device would otherwise fill
> > dmesg with i2c read errors.
> > 
> > Signed-off-by: Chris Morgan <macromorgan at hotmail.com>
> 
> > @@ -1074,12 +1095,18 @@ struct dw_hdmi_qp *dw_hdmi_qp_bind(struct platform_device *pdev,
> >  	if (ret)
> >  		return ERR_PTR(ret);
> >  
> > +	if (of_property_present(pdev->dev.of_node, "no-hpd"))
> > +		hdmi->no_hpd = 1;
> > +	else
> > +		hdmi->no_hpd = 0;
> > +
> 
> what is the argument against
> 
> hdmi->no_hpd = of_property_read_bool(pdev->dev.of_node, "no-hpd")); ?

Would be even better to use this, which avoids adding DT specific
code to the bridge driver:

hdmi->no_hpd = device_property_read_bool(pdev->dev, "no-hpd");

Greetings,

-- Sebastian
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: not available
URL: <http://lists.infradead.org/pipermail/linux-rockchip/attachments/20251107/8bce544d/attachment.sig>


More information about the Linux-rockchip mailing list