Hi Dmitry, Thank you for the patch.
On Sat, Aug 02, 2025 at 01:40:35PM +0300, Dmitry Baryshkov wrote: > Detecting the monitor for DisplayPort targets is more complicated than > just reading the HPD pin level: it requires reading the DPCD in order to > check what kind of device is attached to the port and whether there is > an actual display attached. > > In order to let DRM framework handle such configurations, disable > DRM_BRIDGE_OP_DETECT for dp-connector devices, letting the actual DP > driver perform detection. This still keeps DRM_BRIDGE_OP_HPD enabled, so > it is valid for the bridge to report HPD events. > > Currently inside the kernel there are only two targets which list > hpd-gpios for dp-connector devices: arm64/qcom/qcs6490-rb3gen2 and > arm64/qcom/sa8295p-adp. Both should be fine with this change. > > Cc: Bjorn Andersson <anders...@kernel.org> > Cc: Konrad Dybcio <konradyb...@kernel.org> > Cc: linux-arm-...@vger.kernel.org > Signed-off-by: Dmitry Baryshkov <dmitry.barysh...@oss.qualcomm.com> Makes sense. Acked-by: Laurent Pinchart <laurent.pinchart+rene...@ideasonboard.com> > --- > drivers/gpu/drm/bridge/display-connector.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/bridge/display-connector.c > b/drivers/gpu/drm/bridge/display-connector.c > index > d7e1c2f8f53cad514ec502d58c1b94d348515b42..e9f16dbc953533c2a2d329ee8fd50c1923a78aac > 100644 > --- a/drivers/gpu/drm/bridge/display-connector.c > +++ b/drivers/gpu/drm/bridge/display-connector.c > @@ -373,7 +373,8 @@ static int display_connector_probe(struct platform_device > *pdev) > if (conn->bridge.ddc) > conn->bridge.ops |= DRM_BRIDGE_OP_EDID > | DRM_BRIDGE_OP_DETECT; > - if (conn->hpd_gpio) > + /* Detecting the monitor requires reading DPCD */ > + if (conn->hpd_gpio && type != DRM_MODE_CONNECTOR_DisplayPort) > conn->bridge.ops |= DRM_BRIDGE_OP_DETECT; > if (conn->hpd_irq >= 0) > conn->bridge.ops |= DRM_BRIDGE_OP_HPD; > > --- > base-commit: 82928cc1c2b2be16ea6ee9e23799ca182e1cd37c > change-id: 20250802-dp-conn-no-detect-b901893b5e3c -- Regards, Laurent Pinchart
