Re: [PATCH v9 20/27] drm/connector: hdmi: Add Infoframes generation

Ville Syrjälä
2024-03-15T08:22:13Z

On Mon, Mar 11, 2024 at 03:49:48PM +0100, Maxime Ripard wrote:
> Infoframes in KMS is usually handled by a bunch of low-level helpers
> that require quite some boilerplate for drivers. This leads to
> discrepancies with how drivers generate them, and which are actually
> sent.
>
> Now that we have everything needed to generate them in the HDMI
> connector state, we can generate them in our common logic so that
> drivers can simply reuse what we precomputed.
>
> Signed-off-by: Maxime Ripard <mripard@kernel.org>
> ---
> drivers/gpu/drm/Kconfig | 1 +
> drivers/gpu/drm/drm_atomic_state_helper.c | 323 +++++++++++++++++++++
> drivers/gpu/drm/drm_connector.c | 14 +
> .../gpu/drm/tests/drm_atomic_state_helper_test.c | 1 +
> drivers/gpu/drm/tests/drm_connector_test.c | 12 +
> include/drm/drm_atomic_state_helper.h | 8 +
> include/drm/drm_connector.h | 133 +++++++++
> 7 files changed, 492 insertions(+)
>
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index 872edb47bb53..ad9c467e20ce 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -97,10 +97,11 @@ config DRM_KUNIT_TEST
> If in doubt, say "N".
>
> config DRM_KMS_HELPER
> tristate
> depends on DRM
> + select DRM_DISPLAY_HDMI_HELPER
> help
> CRTC helpers for KMS drivers.
>
> config DRM_DEBUG_DP_MST_TOPOLOGY_REFS
> bool "Enable refcount backtrace history in the DP MST helpers"
> diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c b/drivers/gpu/drm/drm_atomic_state_helper.c
> index e66272c0d006..2bf53666fc9d 100644
> --- a/drivers/gpu/drm/drm_atomic_state_helper.c
> +++ b/drivers/gpu/drm/drm_atomic_state_helper.c
> @@ -36,10 +36,12 @@
> #include <drm/drm_plane.h>
> #include <drm/drm_print.h>
> #include <drm/drm_vblank.h>
> #include <drm/drm_writeback.h>
>
> +#include <drm/display/drm_hdmi_helper.h>
> +
> #include <linux/slab.h>
> #include <linux/dma-fence.h>
>
> /**
> * DOC: atomic state reset and initialization
> @@ -912,10 +914,143 @@ hdmi_compute_config(const struct drm_connector *connector,
> }
>
> return -EINVAL;
> }
>
> +static int hdmi_generate_avi_infoframe(const struct drm_connector *connector,
> + struct drm_connector_state *state)
> +{
> + const struct drm_display_mode *mode =
> + connector_state_get_mode(state);
> + struct drm_connector_hdmi_infoframe *infoframe =
> + &state->hdmi.infoframes.avi;
> + struct hdmi_avi_infoframe *frame =
> + &infoframe->data.avi;
> + bool is_full_range = state->hdmi.is_full_range;
> + enum hdmi_quantization_range rgb_quant_range =
> + is_full_range ? HDMI_QUANTIZATION_RANGE_FULL : HDMI_QUANTIZATION_RANGE_LIMITED;
> + int ret;
> +
> + ret = drm_hdmi_avi_infoframe_from_display_mode(frame, connector, mode);
> + if (ret)
> + return ret;
> +
> + frame->colorspace = state->hdmi.output_format;
> +
> + drm_hdmi_avi_infoframe_quant_range(frame, connector, mode, rgb_quant_range);

drm_hdmi_avi_infoframe_quant_range() doesn't handle YCbCr currently.

> + drm_hdmi_avi_infoframe_colorimetry(frame, state);
> + drm_hdmi_avi_infoframe_bars(frame, state);
> +
> + infoframe->set = true;
> +
> + return 0;
> +}
> +
<snip>
> +
> +#define UPDATE_INFOFRAME(c, os, ns, i) \
> + write_or_clear_infoframe(c, \
> + &(c)->hdmi.infoframes.i, \
> + &(os)->hdmi.infoframes.i, \
> + &(ns)->hdmi.infoframes.i)

This macro feels like pointless obfuscation to me.

<snip>
> @@ -1984,20 +2063,73 @@ struct drm_connector {
>
> /**
> * @hdmi: HDMI-related variable and properties.
> */
> struct {
> +#define DRM_CONNECTOR_HDMI_VENDOR_LEN 8
> + /**
> + * @vendor: HDMI Controller Vendor Name
> + */
> + unsigned char vendor[DRM_CONNECTOR_HDMI_VENDOR_LEN] __nonstring;
> +
> +#define DRM_CONNECTOR_HDMI_PRODUCT_LEN 16
> + /**
> + * @product: HDMI Controller Product Name
> + */
> + unsigned char product[DRM_CONNECTOR_HDMI_PRODUCT_LEN] __nonstring;
> +
> /**
> * @supported_formats: Bitmask of @hdmi_colorspace
> * supported by the controller.
> */
> unsigned long supported_formats;
>
> /**
> * @funcs: HDMI connector Control Functions
> */
> const struct drm_connector_hdmi_funcs *funcs;
> +
> + /**
> + * @infoframes: Current Infoframes output by the connector
> + */
> + struct {
> + /**
> + * @lock: Mutex protecting against concurrent access to
> + * the infoframes, most notably between KMS and ALSA.
> + */
> + struct mutex lock;
> +
> + /**
> + * @audio: Current Audio Infoframes structure. Protected
> + * by @lock.
> + */
> + struct drm_connector_hdmi_infoframe audio;
> +
> + /**
> + * @avi: Current AVI Infoframes structure. Protected by
> + * @lock.
> + */
> + struct drm_connector_hdmi_infoframe avi;
> +
> + /**
> + * @hdr_drm: Current DRM (Dynamic Range and Mastering)
> + * Infoframes structure. Protected by @lock.
> + */
> + struct drm_connector_hdmi_infoframe hdr_drm;
> +
> + /**
> + * @spd: Current SPD Infoframes structure. Protected by
> + * @lock.
> + */
> + struct drm_connector_hdmi_infoframe spd;
> +
> + /**
> + * @vendor: Current HDMI Vendor Infoframes structure.
> + * Protected by @lock.
> + */
> + struct drm_connector_hdmi_infoframe hdmi;
> + } infoframes;
> } hdmi;

What's the deal with this bloat? These are already tracked in the
connector's state so this looks entirely redundant.

> };
>
> #define obj_to_connector(x) container_of(x, struct drm_connector, base)
>
> @@ -2015,10 +2147,11 @@ int drmm_connector_init(struct drm_device *dev,
> const struct drm_connector_funcs *funcs,
> int connector_type,
> struct i2c_adapter *ddc);
> int drmm_connector_hdmi_init(struct drm_device *dev,
> struct drm_connector *connector,
> + const char *vendor, const char *product,
> const struct drm_connector_funcs *funcs,
> const struct drm_connector_hdmi_funcs *hdmi_funcs,
> int connector_type,
> struct i2c_adapter *ddc,
> unsigned long supported_formats,
>
> --
> 2.43.2

--
Ville Syrjälä
Intel