Re: [PATCH 3/4] drm: xlnx: zynqmp_dpsub: Set input live format

Laurent Pinchart
2024-02-28T16:08:02Z

Hi Anatoliy,

Thank you for the patch.

On Mon, Feb 26, 2024 at 08:44:44PM -0800, Anatoliy Klymenko wrote:
> Program live video input format according to selected media bus format.
>
> In the bridge mode of operation, DPSUB is connected to FPGA CRTC which
> almost certainly supports a single media bus format as its output. Expect
> this to be delivered via the new bridge atomic state. Program DPSUB
> registers accordingly.
>
> Signed-off-by: Anatoliy Klymenko <anatoliy.klymenko@amd.com>
> ---
> drivers/gpu/drm/xlnx/zynqmp_disp.c | 52 +++++++++++++++++++++++++++++++++
> drivers/gpu/drm/xlnx/zynqmp_disp.h | 2 ++
> drivers/gpu/drm/xlnx/zynqmp_disp_regs.h | 8 ++---
> drivers/gpu/drm/xlnx/zynqmp_dp.c | 13 ++++++---
> 4 files changed, 67 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/xlnx/zynqmp_disp.c b/drivers/gpu/drm/xlnx/zynqmp_disp.c
> index ee99aad915ba..1c3ffdee6b8e 100644
> --- a/drivers/gpu/drm/xlnx/zynqmp_disp.c
> +++ b/drivers/gpu/drm/xlnx/zynqmp_disp.c
> @@ -416,6 +416,34 @@ static bool zynqmp_disp_layer_is_video(const struct zynqmp_disp_layer *layer)
> return layer->id == ZYNQMP_DPSUB_LAYER_VID;
> }
>
> +/**
> + * zynqmp_disp_avbuf_set_live_format - Set live input format for a layer
> + * @disp: Display controller
> + * @layer: The layer
> + * @fmt: The format information
> + *
> + * Set the live video input format for @layer to @fmt.
> + */
> +static void zynqmp_disp_avbuf_set_live_format(struct zynqmp_disp *disp,
> + struct zynqmp_disp_layer *layer,
> + const struct zynqmp_disp_format *fmt)
> +{
> + u32 reg, i;
> +
> + reg = zynqmp_disp_layer_is_video(layer)
> + ? ZYNQMP_DISP_AV_BUF_LIVE_VID_CONFIG
> + : ZYNQMP_DISP_AV_BUF_LIVE_GFX_CONFIG;
> + zynqmp_disp_avbuf_write(disp, reg, fmt->buf_fmt);
> +
> + for (i = 0; i < ZYNQMP_DISP_AV_BUF_NUM_SF; ++i) {
> + reg = zynqmp_disp_layer_is_video(layer)
> + ? ZYNQMP_DISP_AV_BUF_LIVD_VID_COMP_SF(i)
> + : ZYNQMP_DISP_AV_BUF_LIVD_GFX_COMP_SF(i);
> + zynqmp_disp_avbuf_write(disp, reg, fmt->sf[i]);
> + }

This is identical to zynqmp_disp_avbuf_set_format(), you should avoid
duplicating code.

> + layer->disp_fmt = fmt;
> +}
> +
> /**
> * zynqmp_disp_avbuf_set_format - Set the input format for a layer
> * @disp: Display controller
> @@ -979,6 +1007,30 @@ void zynqmp_disp_layer_disable(struct zynqmp_disp_layer *layer)
> zynqmp_disp_blend_layer_disable(layer->disp, layer);
> }
>
> +/**
> + * zynqmp_disp_layer_set_live_format - Set live layer input format
> + * @layer: The layer
> + * @info: Input media bus format
> + *
> + * Set the live @layer input bus format. The layer must be disabled.
> + */
> +void zynqmp_disp_layer_set_live_format(struct zynqmp_disp_layer *layer,
> + u32 bus_format)

I'd prefer reusing zynqmp_disp_layer_set_format(), and handling the
differences between live and non-live input there. There's already a
dma_enabled check in that function.

> +{
> + int i;
> + const struct zynqmp_disp_format *fmt;
> +
> + for (i = 0; i < ARRAY_SIZE(avbuf_live_fmts); ++i) {
> + fmt = &avbuf_live_fmts[i];
> + if (fmt->bus_fmt == bus_format) {
> + layer->disp_fmt = fmt;
> + layer->drm_fmt = drm_format_info(fmt->drm_fmt);
> + zynqmp_disp_avbuf_set_live_format(layer->disp, layer, fmt);
> + return;
> + }
> + }
> +}
> +
> /**
> * zynqmp_disp_layer_set_format - Set the layer format
> * @layer: The layer
> diff --git a/drivers/gpu/drm/xlnx/zynqmp_disp.h b/drivers/gpu/drm/xlnx/zynqmp_disp.h
> index c2c8dd4896ba..f244b7d2346a 100644
> --- a/drivers/gpu/drm/xlnx/zynqmp_disp.h
> +++ b/drivers/gpu/drm/xlnx/zynqmp_disp.h
> @@ -66,6 +66,8 @@ void zynqmp_disp_layer_enable(struct zynqmp_disp_layer *layer);
> void zynqmp_disp_layer_disable(struct zynqmp_disp_layer *layer);
> void zynqmp_disp_layer_set_format(struct zynqmp_disp_layer *layer,
> const struct drm_format_info *info);
> +void zynqmp_disp_layer_set_live_format(struct zynqmp_disp_layer *layer,
> + u32 bus_format);
> int zynqmp_disp_layer_update(struct zynqmp_disp_layer *layer,
> struct drm_plane_state *state);
>
> diff --git a/drivers/gpu/drm/xlnx/zynqmp_disp_regs.h b/drivers/gpu/drm/xlnx/zynqmp_disp_regs.h
> index f92a006d5070..fa3935384834 100644
> --- a/drivers/gpu/drm/xlnx/zynqmp_disp_regs.h
> +++ b/drivers/gpu/drm/xlnx/zynqmp_disp_regs.h
> @@ -165,10 +165,10 @@
> #define ZYNQMP_DISP_AV_BUF_LIVE_CONFIG_BPC_10 0x2
> #define ZYNQMP_DISP_AV_BUF_LIVE_CONFIG_BPC_12 0x3
> #define ZYNQMP_DISP_AV_BUF_LIVE_CONFIG_BPC_MASK GENMASK(2, 0)
> -#define ZYNQMP_DISP_AV_BUF_LIVE_CONFIG_FMT_RGB 0x0
> -#define ZYNQMP_DISP_AV_BUF_LIVE_CONFIG_FMT_YUV444 0x1
> -#define ZYNQMP_DISP_AV_BUF_LIVE_CONFIG_FMT_YUV422 0x2
> -#define ZYNQMP_DISP_AV_BUF_LIVE_CONFIG_FMT_YONLY 0x3
> +#define ZYNQMP_DISP_AV_BUF_LIVE_CONFIG_FMT_RGB (0x0 << 4)
> +#define ZYNQMP_DISP_AV_BUF_LIVE_CONFIG_FMT_YUV444 (0x1 << 4)
> +#define ZYNQMP_DISP_AV_BUF_LIVE_CONFIG_FMT_YUV422 (0x2 << 4)
> +#define ZYNQMP_DISP_AV_BUF_LIVE_CONFIG_FMT_YONLY (0x3 << 4)

This change isn't even mentioned in the commit message. It should be
split to a separate patch.

> #define ZYNQMP_DISP_AV_BUF_LIVE_CONFIG_FMT_MASK GENMASK(5, 4)
> #define ZYNQMP_DISP_AV_BUF_LIVE_CONFIG_CB_FIRST BIT(8)
> #define ZYNQMP_DISP_AV_BUF_PALETTE_MEMORY 0x400
> diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c
> index 9cb7ac9f3097..0d5dffd20ad1 100644
> --- a/drivers/gpu/drm/xlnx/zynqmp_dp.c
> +++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c
> @@ -1281,7 +1281,8 @@ static void zynqmp_dp_disp_enable(struct zynqmp_dp *dp,
> {
> enum zynqmp_dpsub_layer_id layer_id;
> struct zynqmp_disp_layer *layer;
> - const struct drm_format_info *info;
> + struct drm_bridge_state *bridge_state;
> + u32 bus_fmt;
>
> if (dp->dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_LIVE_VIDEO))
> layer_id = ZYNQMP_DPSUB_LAYER_VID;
> @@ -1291,10 +1292,14 @@ static void zynqmp_dp_disp_enable(struct zynqmp_dp *dp,
> return;
>
> layer = dp->dpsub->layers[layer_id];
> + bridge_state = drm_atomic_get_new_bridge_state(old_bridge_state->base.state,
> + old_bridge_state->bridge);
> + if (bridge_state) {
> + bus_fmt = bridge_state->input_bus_cfg.format;
> + zynqmp_disp_layer_set_live_format(layer, bus_fmt);
> + } else
> + return;

if (!bridge_state)
return;

bus_fmt = bridge_state->input_bus_cfg.format;
zynqmp_disp_layer_set_live_format(layer, bus_fmt);

But more importantly, why would this fail ? If it does something is
seriously wrong and the display won't be working. I'd expect at least a
warning, but you should instead ensure it never fails.

>
> - /* TODO: Make the format configurable. */
> - info = drm_format_info(DRM_FORMAT_YUV422);
> - zynqmp_disp_layer_set_format(layer, info);
> zynqmp_disp_layer_enable(layer);
>
> if (layer_id == ZYNQMP_DPSUB_LAYER_GFX)
>

--
Regards,

Laurent Pinchart