Re: [PATCH v6 1/3] media: cec: expose HDMI connector to CEC dev mapping

From: Hans Verkuil
Date: Mon May 20 2019 - 06:27:42 EST

Hi Dariusz,

On 5/17/19 5:42 PM, Dariusz Marcinkiewicz wrote:
> This patch proposes to expose explicit mapping between HDMI connectors
> and /dev/cecX adapters to userland.
>
> New structure with connector info (card number and connector id in case
> of DRM connectors) is added to cec_adapter. That connector info is expected
> to be provided when an adapter is created.
>
> CEC notifier is extended so that it can be used to communicate the
> connector's info to CEC adapters' creators.
>
> New ioctl, exposing connector info to userland, is added to /dev/cec.
>
> Changes since v5:
> - make the patch apply against the latest changes in the affected code
> Changes since v4:
> - small tweaks + added documentation
> Changes since v3:
> - cec_get_connter_conn takes connector_info as argument
> Changes since v2:
> - cec_s_connector_info removed, the connector info is now passed to
> cec_allocate_adapter
> - updated commit message
> Changes since v1:
> Â- removed the unnecessary event,
> Â- extended cec_connctor_info to allow for various types of connectors.
>
> Signed-off-by: Dariusz Marcinkiewicz <darekm@xxxxxxxxxx>
> ---
> Documentation/media/kapi/cec-core.rst | 7 +-
> Documentation/media/uapi/cec/cec-funcs.rst | 1 +
> .../uapi/cec/cec-ioc-adap-g-conn-info.rst | 109 ++++++++++++++++++
> .../display/amdgpu_dm/amdgpu_dm_mst_types.c | 2 +-
> drivers/gpu/drm/bridge/adv7511/adv7511_cec.c | 3 +-
> drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c | 2 +-
> drivers/gpu/drm/drm_dp_cec.c | 22 ++--
> drivers/gpu/drm/i2c/tda9950.c | 3 +-
> drivers/gpu/drm/i915/intel_dp.c | 4 +-
> drivers/gpu/drm/i915/intel_hdmi.c | 6 +-
> drivers/gpu/drm/nouveau/nouveau_connector.c | 3 +-
> drivers/gpu/drm/vc4/vc4_hdmi.c | 8 +-
> drivers/media/cec/cec-adap.c | 13 +++
> drivers/media/cec/cec-api.c | 12 ++
> drivers/media/cec/cec-core.c | 8 +-
> drivers/media/cec/cec-notifier.c | 20 +++-
> drivers/media/cec/cec-pin.c | 2 +-
> drivers/media/i2c/tc358743.c | 3 +-
> .../media/platform/cros-ec-cec/cros-ec-cec.c | 7 +-
> drivers/media/platform/meson/ao-cec.c | 6 +-
> drivers/media/platform/s5p-cec/s5p_cec.c | 6 +-
> drivers/media/platform/seco-cec/seco-cec.c | 8 +-
> drivers/media/platform/sti/cec/stih-cec.c | 6 +-
> drivers/media/platform/stm32/stm32-cec.c | 2 +-
> drivers/media/platform/tegra-cec/tegra_cec.c | 5 +-
> drivers/media/platform/vivid/vivid-cec.c | 2 +-
> drivers/media/usb/pulse8-cec/pulse8-cec.c | 3 +-
> .../media/usb/rainshadow-cec/rainshadow-cec.c | 3 +-
> include/drm/drm_dp_helper.h | 14 +--
> include/media/cec-notifier.h | 34 ++++--
> include/media/cec.h | 16 ++-
> include/uapi/linux/cec.h | 24 ++++
> 32 files changed, 310 insertions(+), 54 deletions(-)
> create mode 100644 Documentation/media/uapi/cec/cec-ioc-adap-g-conn-info.rst
>

I've been doing some testing with my Khadas VIM2 board (amlogic SoC).

It's a bit unusual since it uses the Synopsys bridge, but not the Synopsys
CEC driver (it has its own meson cec driver).

The first thing I noticed is that I did not get any connector info.
I think that the root cause of that is that you forgot that there are
several drm drivers that call cec_notifier_get() instead of cec_notifier_get_conn().

I think all those calls to cec_notifier_get() in drm drivers should be replaced
by cec_notifier_get_conn() where the second argument is NULL, but the third argument
should contain valid connector info.

A quick grep gives me the following drivers that need work:

drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
drivers/gpu/drm/exynos/exynos_hdmi.c
drivers/gpu/drm/i2c/tda998x_drv.c
drivers/gpu/drm/sti/sti_hdmi.c
drivers/gpu/drm/tegra/output.c

The second thing I noticed is that patch 2 gave me a new kernel warning, but
I'll do some more testing for that and reply to patch 2/3 once I know more.

Regards,

Hans