Hi Laurent, On Wed, 2024-09-25 at 19:36 +0300, Laurent Pinchart wrote: > Hi Steffen, > > On Wed, Sep 25, 2024 at 09:54:18AM +0200, Steffen Dirkwinkel wrote: > > On Tue, 2024-09-24 at 21:43 +0300, Laurent Pinchart wrote: > > > On Mon, Sep 23, 2024 at 09:48:03AM +0200, lists@xxxxxxxxxx wrote: > > > > From: Steffen Dirkwinkel <s.dirkwinkel@xxxxxxxxxxxx> > > > > > > > > With hpd going through the bridge as of commit eb2d64bfcc17 > > > > ("drm: xlnx: zynqmp_dpsub: Report HPD through the bridge") > > > > we don't get hotplug events in userspace on zynqmp hardware. > > > > Also sending hotplug events with drm_helper_hpd_irq_event > > > > works. > > > > > > Why does the driver need to call both drm_helper_hpd_irq_event() > > > and > > > drm_bridge_hpd_notify() ? The latter should end up calling > > > drm_kms_helper_connector_hotplug_event(), which is the same > > > function > > > that drm_helper_hpd_irq_event() calls. > > > > I don't know why we need drm_helper_hpd_irq_event. > > I'll try to trace what happens on hotplug. > > Thank you. Let's try to find the best solution based on your > findings. There's just nothing registering for hpd with "drm_bridge_connector_enable_hpd" or "drm_bridge_hpd_enable". I'm not sure what the correct way to implement this is. In "drivers/gpu/drm/bridge/ti-tfp410.c" the driver registers for the callback and calls "drm_helper_hpd_irq_event" in the callback. I guess we could also do that, but then we might as well call drm_helper_hpd_irq_event directly? Some other drivers just call both like I did here. (drivers/gpu/drm/mediatek/mtk_hdmi.c for example) For "drivers/gpu/drm/msm/hdmi/hdmi_bridge.c" I also can't find the hpd enable call and it just calls drm_bridge_hpd_notify. > > > > > Fixes: eb2d64bfcc17 ("drm: xlnx: zynqmp_dpsub: Report HPD > > > > through > > > > the bridge") > > > > Signed-off-by: Steffen Dirkwinkel <s.dirkwinkel@xxxxxxxxxxxx> > > > > --- > > > > drivers/gpu/drm/xlnx/zynqmp_dp.c | 4 ++++ > > > > 1 file changed, 4 insertions(+) > > > > > > > > diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c > > > > b/drivers/gpu/drm/xlnx/zynqmp_dp.c > > > > index 1846c4971fd8..cb823540a412 100644 > > > > --- a/drivers/gpu/drm/xlnx/zynqmp_dp.c > > > > +++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c > > > > @@ -17,6 +17,7 @@ > > > > #include <drm/drm_fourcc.h> > > > > #include <drm/drm_modes.h> > > > > #include <drm/drm_of.h> > > > > +#include <drm/drm_probe_helper.h> > > > > > > > > #include <linux/clk.h> > > > > #include <linux/delay.h> > > > > @@ -1614,6 +1615,9 @@ static void > > > > zynqmp_dp_hpd_work_func(struct > > > > work_struct *work) > > > > hpd_work.work); > > > > enum drm_connector_status status; > > > > > > > > + if (dp->bridge.dev) > > > > + drm_helper_hpd_irq_event(dp->bridge.dev); > > > > + > > > > status = zynqmp_dp_bridge_detect(&dp->bridge); > > > > drm_bridge_hpd_notify(&dp->bridge, status); > > > > } >