Re: [PATCH v2 05/15] drm/vc4: hdmi: Restore cec physical address on reconnect

Dave Stevenson
2021-01-22T10:33:35Z

Hi Maxime

Sorry for the slow reply on these patches.

On Mon, 11 Jan 2021 at 14:23, Maxime Ripard <maxime@cerno.tech> wrote:
>
> From: Dom Cobley <popcornmix@gmail.com>
>
> Currently we call cec_phys_addr_invalidate on a hotplug deassert.
> That may be due to a TV power cycling, or an AVR being switched
> on (and switching edid).
>
> This makes CEC unusable since our controller wouldn't have a physical
> address anymore.
>
> Set it back up again on the hotplug assert.
>
> Fixes: 15b4511a4af6 ("drm/vc4: add HDMI CEC support")
> Signed-off-by: Dom Cobley <popcornmix@gmail.com>
> Signed-off-by: Maxime Ripard <maxime@cerno.tech>

I follow the logic, and trust Dom that it works, but I don't know if
that is the correct thing within CEC.
Ideally Hans will comment as the original author of the CEC code - I
believe he's testing the series anyway.

Acked-by: Dave Stevenson <dave.stevenson@raspberrypi.com>

> ---
> drivers/gpu/drm/vc4/vc4_hdmi.c | 24 ++++++++++++++++++------
> 1 file changed, 18 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
> index 7945dbcee78c..c3a301396aad 100644
> --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
> +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
> @@ -136,20 +136,32 @@ static enum drm_connector_status
> vc4_hdmi_connector_detect(struct drm_connector *connector, bool force)
> {
> struct vc4_hdmi *vc4_hdmi = connector_to_vc4_hdmi(connector);
> + bool connected = false;
>
> if (vc4_hdmi->hpd_gpio) {
> if (gpio_get_value_cansleep(vc4_hdmi->hpd_gpio) ^
> vc4_hdmi->hpd_active_low)
> - return connector_status_connected;
> - cec_phys_addr_invalidate(vc4_hdmi->cec_adap);
> - return connector_status_disconnected;
> + connected = true;
> + } else if (drm_probe_ddc(vc4_hdmi->ddc)) {
> + connected = true;
> + } else if (HDMI_READ(HDMI_HOTPLUG) & VC4_HDMI_HOTPLUG_CONNECTED) {
> + connected = true;
> }
>
> - if (drm_probe_ddc(vc4_hdmi->ddc))
> - return connector_status_connected;
> + if (connected) {
> + if (connector->status != connector_status_connected) {
> + struct edid *edid = drm_get_edid(connector, vc4_hdmi->ddc);
> +
> + if (edid) {
> + cec_s_phys_addr_from_edid(vc4_hdmi->cec_adap, edid);
> + vc4_hdmi->encoder.hdmi_monitor = drm_detect_hdmi_monitor(edid);
> + kfree(edid);
> + }
> + }
>
> - if (HDMI_READ(HDMI_HOTPLUG) & VC4_HDMI_HOTPLUG_CONNECTED)
> return connector_status_connected;
> + }
> +
> cec_phys_addr_invalidate(vc4_hdmi->cec_adap);
> return connector_status_disconnected;
> }
> --
> 2.29.2