On Fri, May 26, 2017 at 12:20:48PM +0200, Hans Verkuil wrote:
> On 05/26/2017 09:15 AM, Daniel Vetter wrote:
> > On Thu, May 25, 2017 at 05:06:26PM +0200, Hans Verkuil wrote:
> >> From: Hans Verkuil <hans.verkuil@xxxxxxxxx>
> >>
> >> Implement support for this DisplayPort feature.
> >>
> >> The cec device is created whenever it detects an adapter that
> >> has this feature. It is only removed when a new adapter is connected
> >> that does not support this. If a new adapter is connected that has
> >> different properties than the previous one, then the old cec device is
> >> unregistered and a new one is registered to replace the old one.
> >>
> >> Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
> >
> > Some small comments below.
> >
> >> ---
> >> drivers/gpu/drm/i915/Kconfig | 11 ++++++++++
> >> drivers/gpu/drm/i915/intel_dp.c | 46 +++++++++++++++++++++++++++++++++++++----
> >> 2 files changed, 53 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/i915/Kconfig b/drivers/gpu/drm/i915/Kconfig
> >> index a5cd5dacf055..f317b13a1409 100644
> >> --- a/drivers/gpu/drm/i915/Kconfig
> >> +++ b/drivers/gpu/drm/i915/Kconfig
> >> @@ -124,6 +124,17 @@ config DRM_I915_GVT_KVMGT
> >> Choose this option if you want to enable KVMGT support for
> >> Intel GVT-g.
> >>
> >> +config DRM_I915_DP_CEC
> >> + tristate "Enable DisplayPort CEC-Tunneling-over-AUX HDMI support"
> >> + depends on DRM_I915 && CEC_CORE
> >> + select DRM_DP_CEC
> >> + help
> >> + Choose this option if you want to enable HDMI CEC support for
> >> + DisplayPort/USB-C to HDMI adapters.
> >> +
> >> + Note: not all adapters support this feature, and even for those
> >> + that do support this often do not hook up the CEC pin.
> >
> > Why Kconfig? There's not anything else optional in i915.ko (except debug
> > stuff ofc), since generally just not worth the pain. Also doesn't seem to
> > be wired up at all :-)
>
> It selects DRM_DP_CEC, but you're right, it can be dropped.
>
> >
> >> +
> >> menu "drm/i915 Debugging"
> >> depends on DRM_I915
> >> depends on EXPERT
> >> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> >> index ee77b519835c..38e17ee2548d 100644
> >> --- a/drivers/gpu/drm/i915/intel_dp.c
> >> +++ b/drivers/gpu/drm/i915/intel_dp.c
> >> @@ -32,6 +32,7 @@
> >> #include <linux/notifier.h>
> >> #include <linux/reboot.h>
> >> #include <asm/byteorder.h>
> >> +#include <media/cec.h>
> >> #include <drm/drmP.h>
> >> #include <drm/drm_atomic_helper.h>
> >> #include <drm/drm_crtc.h>
> >> @@ -1405,6 +1406,7 @@ static void intel_aux_reg_init(struct intel_dp *intel_dp)
> >> static void
> >> intel_dp_aux_fini(struct intel_dp *intel_dp)
> >> {
> >> + cec_unregister_adapter(intel_dp->aux.cec_adap);
> >> kfree(intel_dp->aux.name);
> >> }
> >>
> >> @@ -4179,6 +4181,33 @@ intel_dp_check_mst_status(struct intel_dp *intel_dp)
> >> return -EINVAL;
> >> }
> >>
> >> +static bool
> >> +intel_dp_check_cec_status(struct intel_dp *intel_dp)
> >> +{
> >> + bool handled = false;
> >> +
> >> + for (;;) {
> >> + u8 cec_irq;
> >> + int ret;
> >> +
> >> + ret = drm_dp_dpcd_readb(&intel_dp->aux,
> >> + DP_DEVICE_SERVICE_IRQ_VECTOR_ESI1,
> >> + &cec_irq);
> >> + if (ret < 0 || !(cec_irq & DP_CEC_IRQ))
> >> + return handled;
> >> +
> >> + cec_irq &= ~DP_CEC_IRQ;
> >> + drm_dp_cec_irq(&intel_dp->aux);
> >> + handled = true;
> >> +
> >> + ret = drm_dp_dpcd_writeb(&intel_dp->aux,
> >> + DP_DEVICE_SERVICE_IRQ_VECTOR_ESI1,
> >> + cec_irq);
> >> + if (ret < 0)
> >> + return handled;
> >> + }
> >> +}
> >
> > Shouldn't the above be a helper in the cec library? Doesn't look i915
> > specific to me at least ...
>
> Good point, this can be moved to drm_dp_cec_irq().
>
> >
> >> +
> >> static void
> >> intel_dp_retrain_link(struct intel_dp *intel_dp)
> >> {
> >> @@ -4553,6 +4582,7 @@ intel_dp_set_edid(struct intel_dp *intel_dp)
> >> intel_dp->has_audio = intel_dp->force_audio == HDMI_AUDIO_ON;
> >> else
> >> intel_dp->has_audio = drm_detect_monitor_audio(edid);
> >> + cec_s_phys_addr_from_edid(intel_dp->aux.cec_adap, edid);
> >> }
> >>
> >> static void
> >> @@ -4562,6 +4592,7 @@ intel_dp_unset_edid(struct intel_dp *intel_dp)
> >>
> >> kfree(intel_connector->detect_edid);
> >> intel_connector->detect_edid = NULL;
> >> + cec_phys_addr_invalidate(intel_dp->aux.cec_adap);
> >>
> >> intel_dp->has_audio = false;
> >> }
> >> @@ -4582,13 +4613,17 @@ intel_dp_long_pulse(struct intel_connector *intel_connector)
> >> intel_display_power_get(to_i915(dev), intel_dp->aux_power_domain);
> >>
> >> /* Can't disconnect eDP, but you can close the lid... */
> >> - if (is_edp(intel_dp))
> >> + if (is_edp(intel_dp)) {
> >> status = edp_detect(intel_dp);
> >> - else if (intel_digital_port_connected(to_i915(dev),
> >> - dp_to_dig_port(intel_dp)))
> >> + } else if (intel_digital_port_connected(to_i915(dev),
> >> + dp_to_dig_port(intel_dp))) {
> >> status = intel_dp_detect_dpcd(intel_dp);
> >> - else
> >> + if (status == connector_status_connected)
> >> + drm_dp_cec_configure_adapter(&intel_dp->aux,
> >> + intel_dp->aux.name, dev->dev);
> >
> > Did you look into also wiring this up for dp mst chains?
>
> Isn't this sufficient? I have no way of testing mst chains.
>
> I think I need some pointers from you, since I am a complete newbie when it
> comes to mst.
I don't really have more clue, but yeah if you don't have an mst thing (a
simple dp port multiplexer is what I use for testing here, then plug in a
converter dongle or cable into that) then probably better to not wire up
the code for it.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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