Re: [PATCH v3 2/3] media: hantro: Support color conversion via post-processing

From: Philipp Zabel
Date: Thu Nov 14 2019 - 04:49:00 EST


Hi Ezequiel,

On Wed, 2019-11-13 at 14:56 -0300, Ezequiel Garcia wrote:
> The Hantro G1 decoder is able to enable a post-processor
> on the decoding pipeline, which can be used to perform
> scaling and color conversion.
>
> The post-processor is integrated to the decoder, and it's
> possible to use it in a way that is completely transparent
> to the user.
>
> This commit enables color conversion via post-processing,
> which means the driver now exposes YUV packed, in addition to NV12.
>
> Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>
> ---
> drivers/staging/media/hantro/Makefile | 1 +
> drivers/staging/media/hantro/hantro.h | 64 +++++++-
> drivers/staging/media/hantro/hantro_drv.c | 8 +-
> .../staging/media/hantro/hantro_g1_h264_dec.c | 2 +-
> .../media/hantro/hantro_g1_mpeg2_dec.c | 2 +-
> drivers/staging/media/hantro/hantro_g1_regs.h | 53 +++++++
> .../staging/media/hantro/hantro_g1_vp8_dec.c | 2 +-
> drivers/staging/media/hantro/hantro_h264.c | 6 +-
> drivers/staging/media/hantro/hantro_hw.h | 13 ++
> .../staging/media/hantro/hantro_postproc.c | 141 ++++++++++++++++++
> drivers/staging/media/hantro/hantro_v4l2.c | 52 ++++++-
> drivers/staging/media/hantro/rk3288_vpu_hw.c | 10 ++
> 12 files changed, 343 insertions(+), 11 deletions(-)
> create mode 100644 drivers/staging/media/hantro/hantro_postproc.c
>
> diff --git a/drivers/staging/media/hantro/Makefile b/drivers/staging/media/hantro/Makefile
> index 5d6b0383d280..496b30c3c396 100644
> --- a/drivers/staging/media/hantro/Makefile
> +++ b/drivers/staging/media/hantro/Makefile
> @@ -3,6 +3,7 @@ obj-$(CONFIG_VIDEO_HANTRO) += hantro-vpu.o
> hantro-vpu-y += \
> hantro_drv.o \
> hantro_v4l2.o \
> + hantro_postproc.o \
> hantro_h1_jpeg_enc.o \
> hantro_g1_h264_dec.o \
> hantro_g1_mpeg2_dec.o \
> diff --git a/drivers/staging/media/hantro/hantro.h b/drivers/staging/media/hantro/hantro.h
> index deb90ae37859..6016a1a42503 100644
> --- a/drivers/staging/media/hantro/hantro.h
> +++ b/drivers/staging/media/hantro/hantro.h
> @@ -60,6 +60,8 @@ struct hantro_irq {
> * @num_enc_fmts: Number of encoder formats.
> * @dec_fmts: Decoder formats.
> * @num_dec_fmts: Number of decoder formats.
> + * @postproc_fmts: Post-processor formats.
> + * @num_postproc_fmts: Number of post-processor formats.
> * @codec: Supported codecs
> * @codec_ops: Codec ops.
> * @init: Initialize hardware.
> @@ -70,6 +72,7 @@ struct hantro_irq {
> * @num_clocks: number of clocks in the array
> * @reg_names: array of register range names
> * @num_regs: number of register range names in the array
> + * @postproc_regs: &struct hantro_postproc_regs pointer
> */
> struct hantro_variant {
> unsigned int enc_offset;
> @@ -78,6 +81,8 @@ struct hantro_variant {
> unsigned int num_enc_fmts;
> const struct hantro_fmt *dec_fmts;
> unsigned int num_dec_fmts;
> + const struct hantro_fmt *postproc_fmts;
> + unsigned int num_postproc_fmts;
> unsigned int codec;
> const struct hantro_codec_ops *codec_ops;
> int (*init)(struct hantro_dev *vpu);
> @@ -88,6 +93,7 @@ struct hantro_variant {
> int num_clocks;
> const char * const *reg_names;
> int num_regs;
> + const struct hantro_postproc_regs *postproc_regs;
> };
>
> /**
> @@ -213,6 +219,7 @@ struct hantro_dev {
> * context, and it's called right before
> * calling v4l2_m2m_job_finish.
> * @codec_ops: Set of operations related to codec mode.
> + * @postproc: Post-processing context.
> * @jpeg_enc: JPEG-encoding context.
> * @mpeg2_dec: MPEG-2-decoding context.
> * @vp8_dec: VP8-decoding context.
> @@ -237,6 +244,7 @@ struct hantro_ctx {
> unsigned int bytesused);
>
> const struct hantro_codec_ops *codec_ops;
> + struct hantro_postproc_ctx postproc;
>
> /* Specific for particular codec modes. */
> union {
> @@ -274,6 +282,23 @@ struct hantro_reg {
> u32 mask;
> };
>
> +struct hantro_postproc_regs {
> + struct hantro_reg pipeline_en;
> + struct hantro_reg max_burst;
> + struct hantro_reg clk_gate;
> + struct hantro_reg out_swap32;
> + struct hantro_reg out_endian;
> + struct hantro_reg out_luma_base;
> + struct hantro_reg input_width;
> + struct hantro_reg input_height;
> + struct hantro_reg output_width;
> + struct hantro_reg output_height;
> + struct hantro_reg input_fmt;
> + struct hantro_reg output_fmt;
> + struct hantro_reg orig_width;
> + struct hantro_reg display_width;
> +};
> +
> /* Logging helpers */
>
> /**
> @@ -352,9 +377,23 @@ static inline u32 vdpu_read(struct hantro_dev *vpu, u32 reg)
> return val;
> }
>
> -static inline void hantro_reg_write(struct hantro_dev *vpu,
> - const struct hantro_reg *reg,
> - u32 val)
> +static inline void
> +hantro_reg_write(struct hantro_dev *vpu,
> + const struct hantro_reg *reg,
> + u32 val)
> +{
> + u32 v;
> +
> + v = vdpu_read(vpu, reg->base);
> + v &= ~(reg->mask << reg->shift);
> + v |= ((val & reg->mask) << reg->shift);
> + vdpu_write(vpu, v, reg->base);
> +}

This adds barriers to all the currently relaxed writes in the VP8
decoders. Maybe split this into a separate patch and add an explanation.

> +
> +static inline void
> +hantro_reg_write_relaxed(struct hantro_dev *vpu,
> + const struct hantro_reg *reg,
> + u32 val)
> {
> u32 v;
>
> @@ -381,4 +420,23 @@ hantro_get_dst_buf(struct hantro_ctx *ctx)
> return v4l2_m2m_next_dst_buf(ctx->fh.m2m_ctx);
> }
>
> +static inline bool
> +hantro_needs_postproc(struct hantro_ctx *ctx)
> +{
> + return ctx->vpu_dst_fmt->fourcc != V4L2_PIX_FMT_NV12;
> +}
> +
> +static inline dma_addr_t
> +hantro_get_dec_buf_addr(struct hantro_ctx *ctx, struct vb2_buffer *vb)
> +{
> + if (hantro_needs_postproc(ctx))
> + return ctx->postproc.dec_q[vb->index].dma;
> + return vb2_dma_contig_plane_dma_addr(vb, 0);
> +}
> +
> +void hantro_postproc_disable(struct hantro_ctx *ctx);
> +void hantro_postproc_setup(struct hantro_ctx *ctx);
> +void hantro_postproc_free(struct hantro_ctx *ctx);
> +int hantro_postproc_alloc(struct hantro_ctx *ctx);
> +
> #endif /* HANTRO_H_ */
> diff --git a/drivers/staging/media/hantro/hantro_drv.c b/drivers/staging/media/hantro/hantro_drv.c
> index 26108c96b674..fb08296db168 100644
> --- a/drivers/staging/media/hantro/hantro_drv.c
> +++ b/drivers/staging/media/hantro/hantro_drv.c
> @@ -53,7 +53,7 @@ dma_addr_t hantro_get_ref(struct hantro_ctx *ctx, u64 ts)
> if (index < 0)
> return 0;
> buf = vb2_get_buffer(q, index);
> - return vb2_dma_contig_plane_dma_addr(buf, 0);
> + return hantro_get_dec_buf_addr(ctx, buf);
> }
>
> static int
> @@ -159,12 +159,18 @@ void hantro_prepare_run(struct hantro_ctx *ctx)
> src_buf = hantro_get_src_buf(ctx);
> v4l2_ctrl_request_setup(src_buf->vb2_buf.req_obj.req,
> &ctx->ctrl_handler);
> +
> + if (!hantro_needs_postproc(ctx))
> + hantro_postproc_disable(ctx);

Why isn't PP enabled in prepare_run? Does this mean the first frame is
not post-processed?

> }
>
> void hantro_finish_run(struct hantro_ctx *ctx)
> {
> struct vb2_v4l2_buffer *src_buf;
>
> + if (hantro_needs_postproc(ctx))
> + hantro_postproc_setup(ctx);
> +
> src_buf = hantro_get_src_buf(ctx);
> v4l2_ctrl_request_complete(src_buf->vb2_buf.req_obj.req,
> &ctx->ctrl_handler);
> diff --git a/drivers/staging/media/hantro/hantro_g1_h264_dec.c b/drivers/staging/media/hantro/hantro_g1_h264_dec.c
> index 70a6b5b26477..9b292722c9de 100644
> --- a/drivers/staging/media/hantro/hantro_g1_h264_dec.c
> +++ b/drivers/staging/media/hantro/hantro_g1_h264_dec.c
> @@ -243,7 +243,7 @@ static void set_buffers(struct hantro_ctx *ctx)
> vdpu_write_relaxed(vpu, src_dma, G1_REG_ADDR_STR);
>
> /* Destination (decoded frame) buffer. */
> - dst_dma = vb2_dma_contig_plane_dma_addr(&dst_buf->vb2_buf, 0);
> + dst_dma = hantro_get_dec_buf_addr(ctx, &dst_buf->vb2_buf);
> vdpu_write_relaxed(vpu, dst_dma, G1_REG_ADDR_DST);
>
> /* Higher profiles require DMV buffer appended to reference frames. */
> diff --git a/drivers/staging/media/hantro/hantro_g1_mpeg2_dec.c b/drivers/staging/media/hantro/hantro_g1_mpeg2_dec.c
> index f3bf67d8a289..0abe0be2c1ad 100644
> --- a/drivers/staging/media/hantro/hantro_g1_mpeg2_dec.c
> +++ b/drivers/staging/media/hantro/hantro_g1_mpeg2_dec.c
> @@ -121,7 +121,7 @@ hantro_g1_mpeg2_dec_set_buffers(struct hantro_dev *vpu, struct hantro_ctx *ctx,
> vdpu_write_relaxed(vpu, addr, G1_REG_RLC_VLC_BASE);
>
> /* Destination frame buffer */
> - addr = vb2_dma_contig_plane_dma_addr(dst_buf, 0);
> + addr = hantro_get_dec_buf_addr(ctx, dst_buf);
> current_addr = addr;
>
> if (picture->picture_structure == PICT_BOTTOM_FIELD)
> diff --git a/drivers/staging/media/hantro/hantro_g1_regs.h b/drivers/staging/media/hantro/hantro_g1_regs.h
> index 5c0ea7994336..c1756e3d5391 100644
> --- a/drivers/staging/media/hantro/hantro_g1_regs.h
> +++ b/drivers/staging/media/hantro/hantro_g1_regs.h
> @@ -9,6 +9,8 @@
> #ifndef HANTRO_G1_REGS_H_
> #define HANTRO_G1_REGS_H_
>
> +#define G1_SWREG(nr) ((nr) * 4)
> +
> /* Decoder registers. */
> #define G1_REG_INTERRUPT 0x004
> #define G1_REG_INTERRUPT_DEC_PIC_INF BIT(24)
> @@ -298,4 +300,55 @@
> #define G1_REG_REF_BUF_CTRL2_APF_THRESHOLD(x) (((x) & 0x3fff) << 0)
> #define G1_REG_SOFT_RESET 0x194
>
> +/* Post-processor registers. */
> +#define G1_REG_PP_INTERRUPT G1_SWREG(60)
> +#define G1_REG_PP_READY_IRQ BIT(12)
> +#define G1_REG_PP_IRQ BIT(8)
> +#define G1_REG_PP_IRQ_DIS BIT(4)
> +#define G1_REG_PP_PIPELINE_EN BIT(1)
> +#define G1_REG_PP_EXTERNAL_TRIGGER BIT(0)
> +#define G1_REG_PP_DEV_CONFIG G1_SWREG(61)
> +#define G1_REG_PP_AXI_RD_ID(v) (((v) << 24) & GENMASK(31, 24))
> +#define G1_REG_PP_AXI_WR_ID(v) (((v) << 16) & GENMASK(23, 16))
> +#define G1_REG_PP_INSWAP32_E(v) ((v) ? BIT(10) : 0)
> +#define G1_REG_PP_DATA_DISC_E(v) ((v) ? BIT(9) : 0)
> +#define G1_REG_PP_CLK_GATE_E(v) ((v) ? BIT(8) : 0)
> +#define G1_REG_PP_IN_ENDIAN(v) ((v) ? BIT(7) : 0)
> +#define G1_REG_PP_OUT_ENDIAN(v) ((v) ? BIT(6) : 0)
> +#define G1_REG_PP_OUTSWAP32_E(v) ((v) ? BIT(5) : 0)
> +#define G1_REG_PP_MAX_BURST(v) (((v) << 0) & GENMASK(4, 0))
> +#define G1_REG_PP_IN_LUMA_BASE G1_SWREG(63)
> +#define G1_REG_PP_IN_CB_BASE G1_SWREG(64)
> +#define G1_REG_PP_IN_CR_BASE G1_SWREG(65)
> +#define G1_REG_PP_OUT_LUMA_BASE G1_SWREG(66)
> +#define G1_REG_PP_OUT_CHROMA_BASE G1_SWREG(67)
> +#define G1_REG_PP_CONTRAST_ADJUST G1_SWREG(68)
> +#define G1_REG_PP_COLOR_CONVERSION G1_SWREG(69)
> +#define G1_REG_PP_COLOR_CONVERSION0 G1_SWREG(70)
> +#define G1_REG_PP_COLOR_CONVERSION1 G1_SWREG(71)
> +#define G1_REG_PP_INPUT_SIZE G1_SWREG(72)
> +#define G1_REG_PP_INPUT_SIZE_HEIGHT(v) (((v) << 9) & GENMASK(16, 9))
> +#define G1_REG_PP_INPUT_SIZE_WIDTH(v) (((v) << 0) & GENMASK(8, 0))
> +#define G1_REG_PP_SCALING0 G1_SWREG(79)
> +#define G1_REG_PP_PADD_R(v) (((v) << 23) & GENMASK(27, 23))
> +#define G1_REG_PP_PADD_G(v) (((v) << 18) & GENMASK(22, 18))
> +#define G1_REG_PP_RANGEMAP_Y(v) ((v) ? BIT(31) : 0)
> +#define G1_REG_PP_RANGEMAP_C(v) ((v) ? BIT(30) : 0)
> +#define G1_REG_PP_YCBCR_RANGE(v) ((v) ? BIT(29) : 0)
> +#define G1_REG_PP_RGB_16(v) ((v) ? BIT(28) : 0)
> +#define G1_REG_PP_SCALING1 G1_SWREG(80)
> +#define G1_REG_PP_PADD_B(v) (((v) << 18) & GENMASK(22, 18))
> +#define G1_REG_PP_MASK_R G1_SWREG(82)
> +#define G1_REG_PP_MASK_G G1_SWREG(83)
> +#define G1_REG_PP_MASK_B G1_SWREG(84)
> +#define G1_REG_PP_CONTROL G1_SWREG(85)
> +#define G1_REG_PP_CONTROL_IN_FMT(v) (((v) << 29) & GENMASK(31, 29))
> +#define G1_REG_PP_CONTROL_OUT_FMT(v) (((v) << 26) & GENMASK(28, 26))
> +#define G1_REG_PP_CONTROL_OUT_HEIGHT(v) (((v) << 15) & GENMASK(25, 15))
> +#define G1_REG_PP_CONTROL_OUT_WIDTH(v) (((v) << 4) & GENMASK(14, 4))
> +#define G1_REG_PP_MASK1_ORIG_WIDTH G1_SWREG(88)
> +#define G1_REG_PP_ORIG_WIDTH(v) (((v) << 23) & GENMASK(31, 23))
> +#define G1_REG_PP_DISPLAY_WIDTH G1_SWREG(92)
> +#define G1_REG_PP_FUSE G1_SWREG(99)
> +
> #endif /* HANTRO_G1_REGS_H_ */
> diff --git a/drivers/staging/media/hantro/hantro_g1_vp8_dec.c b/drivers/staging/media/hantro/hantro_g1_vp8_dec.c
> index cad18094fee0..e708994d1aba 100644
> --- a/drivers/staging/media/hantro/hantro_g1_vp8_dec.c
> +++ b/drivers/staging/media/hantro/hantro_g1_vp8_dec.c
> @@ -422,7 +422,7 @@ static void cfg_buffers(struct hantro_ctx *ctx,
> }
> vdpu_write_relaxed(vpu, reg, G1_REG_FWD_PIC(0));
>
> - dst_dma = vb2_dma_contig_plane_dma_addr(&vb2_dst->vb2_buf, 0);
> + dst_dma = hantro_get_dec_buf_addr(ctx, &vb2_dst->vb2_buf);
> vdpu_write_relaxed(vpu, dst_dma, G1_REG_ADDR_DST);
> }
>
> diff --git a/drivers/staging/media/hantro/hantro_h264.c b/drivers/staging/media/hantro/hantro_h264.c
> index 694a330f508e..5c84ebcdd0ea 100644
> --- a/drivers/staging/media/hantro/hantro_h264.c
> +++ b/drivers/staging/media/hantro/hantro_h264.c
> @@ -629,7 +629,11 @@ int hantro_h264_dec_init(struct hantro_ctx *ctx)
> tbl = priv->cpu;
> memcpy(tbl->cabac_table, h264_cabac_table, sizeof(tbl->cabac_table));
>
> - v4l2_fill_pixfmt_mp(&pix_mp, ctx->dst_fmt.pixelformat,
> + /*
> + * For the decoder picture size, we want the decoder
> + * native pixel format.
> + */
> + v4l2_fill_pixfmt_mp(&pix_mp, V4L2_PIX_FMT_NV12,
> ctx->dst_fmt.width, ctx->dst_fmt.height);
> h264_dec->pic_size = pix_mp.plane_fmt[0].sizeimage;
>
> diff --git a/drivers/staging/media/hantro/hantro_hw.h b/drivers/staging/media/hantro/hantro_hw.h
> index 69b88f4d3fb3..18e7d9e1f469 100644
> --- a/drivers/staging/media/hantro/hantro_hw.h
> +++ b/drivers/staging/media/hantro/hantro_hw.h
> @@ -28,11 +28,13 @@ struct hantro_variant;
> * @cpu: CPU pointer to the buffer.
> * @dma: DMA address of the buffer.
> * @size: Size of the buffer.
> + * @attrs: Attributes of the DMA mapping.
> */
> struct hantro_aux_buf {
> void *cpu;
> dma_addr_t dma;
> size_t size;
> + unsigned long attrs;
> };
>
> /**
> @@ -109,6 +111,15 @@ struct hantro_vp8_dec_hw_ctx {
> struct hantro_aux_buf prob_tbl;
> };
>
> +/**
> + * struct hantro_postproc_ctx
> + *
> + * @dec_q: References buffers, in decoder format.
> + */
> +struct hantro_postproc_ctx {
> + struct hantro_aux_buf dec_q[VB2_MAX_FRAME];
> +};
> +
> /**
> * struct hantro_codec_ops - codec mode specific operations
> *
> @@ -144,6 +155,8 @@ extern const struct hantro_variant rk3399_vpu_variant;
> extern const struct hantro_variant rk3328_vpu_variant;
> extern const struct hantro_variant rk3288_vpu_variant;
>
> +extern const struct hantro_postproc_regs hantro_g1_postproc_regs;
> +
> extern const u32 hantro_vp8_dec_mc_filter[8][6];
>
> void hantro_watchdog(struct work_struct *work);
> diff --git a/drivers/staging/media/hantro/hantro_postproc.c b/drivers/staging/media/hantro/hantro_postproc.c
> new file mode 100644
> index 000000000000..865435386363
> --- /dev/null
> +++ b/drivers/staging/media/hantro/hantro_postproc.c
> @@ -0,0 +1,141 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Hantro G1 post-processor support
> + *
> + * Copyright (C) 2019 Collabora, Ltd.
> + */
> +
> +#include <linux/dma-mapping.h>
> +#include <linux/types.h>
> +
> +#include "hantro.h"
> +#include "hantro_hw.h"
> +#include "hantro_g1_regs.h"
> +
> +#define HANTRO_PP_REG_WRITE(vpu, reg_name, val) \
> + do { \
> + if ((vpu)->variant->postproc_regs->(reg_name).base) \
> + hantro_reg_write_relaxed((vpu), \
> + &(vpu)->variant->postproc_regs->(reg_name), \
> + (val)); \
> + } while (0)
> +
> +#define HANTRO_PP_REG_WRITE_S(vpu, reg_name, val) \
> + do { \
> + if ((vpu)->variant->postproc_regs->(reg_name).base) \
> + hantro_reg_write((vpu), \
> + &(vpu)->variant->postproc_regs->(reg_name), \
> + (val)); \
> + } while (0)

Why all these checks, are any of the register fields optional?

> +
> +#define VPU_PP_IN_YUYV 0x0
> +#define VPU_PP_IN_NV12 0x1
> +#define VPU_PP_IN_YUV420 0x2
> +#define VPU_PP_IN_YUV240_TILED 0x5
> +#define VPU_PP_OUT_RGB 0x0
> +#define VPU_PP_OUT_YUYV 0x3
> +
> +const struct hantro_postproc_regs hantro_g1_postproc_regs = {
> + .pipeline_en = {G1_REG_PP_INTERRUPT, 1, 0x1},
> + .max_burst = {G1_REG_PP_DEV_CONFIG, 0, 0x1f},
> + .clk_gate = {G1_REG_PP_DEV_CONFIG, 1, 0x1},
> + .out_swap32 = {G1_REG_PP_DEV_CONFIG, 5, 0x1},
> + .out_endian = {G1_REG_PP_DEV_CONFIG, 6, 0x1},
> + .out_luma_base = {G1_REG_PP_OUT_LUMA_BASE, 0, 0xffffffff},
> + .input_width = {G1_REG_PP_INPUT_SIZE, 0, 0x1ff},
> + .input_height = {G1_REG_PP_INPUT_SIZE, 9, 0x1ff},
> + .output_width = {G1_REG_PP_CONTROL, 4, 0x7ff},
> + .output_height = {G1_REG_PP_CONTROL, 15, 0x7ff},
> + .input_fmt = {G1_REG_PP_CONTROL, 29, 0x7},
> + .output_fmt = {G1_REG_PP_CONTROL, 26, 0x7},
> + .orig_width = {G1_REG_PP_MASK1_ORIG_WIDTH, 23, 0x1ff},
> + .display_width = {G1_REG_PP_DISPLAY_WIDTH, 0, 0xfff},
> +};
> +
> +void hantro_postproc_setup(struct hantro_ctx *ctx)
> +{
> + struct hantro_dev *vpu = ctx->dev;
> + struct vb2_v4l2_buffer *dst_buf;
> + u32 src_pp_fmt, dst_pp_fmt;
> + dma_addr_t dst_dma;
> +
> + /* Turn on pipeline mode. Must be done first. */
> + HANTRO_PP_REG_WRITE_S(vpu, pipeline_en, 0x1);
> +
> + src_pp_fmt = VPU_PP_IN_NV12;
> +
> + switch (ctx->vpu_dst_fmt->fourcc) {
> + case V4L2_PIX_FMT_YUYV:
> + dst_pp_fmt = VPU_PP_OUT_YUYV;
> + break;
> + default:
> + WARN(1, "output format %d not supported by the post-processor, this wasn't expected.",
> + ctx->vpu_dst_fmt->fourcc);
> + dst_pp_fmt = 0;
> + break;
> + }
> +
> + dst_buf = v4l2_m2m_next_dst_buf(ctx->fh.m2m_ctx);
> + dst_dma = vb2_dma_contig_plane_dma_addr(&dst_buf->vb2_buf, 0);
> +
> + HANTRO_PP_REG_WRITE(vpu, clk_gate, 0x1);
> + HANTRO_PP_REG_WRITE(vpu, out_endian, 0x1);
> + HANTRO_PP_REG_WRITE(vpu, out_swap32, 0x1);
> + HANTRO_PP_REG_WRITE(vpu, max_burst, 16);
> + HANTRO_PP_REG_WRITE(vpu, out_luma_base, dst_dma);
> + HANTRO_PP_REG_WRITE(vpu, input_width, MB_WIDTH(ctx->dst_fmt.width));
> + HANTRO_PP_REG_WRITE(vpu, input_height, MB_HEIGHT(ctx->dst_fmt.height));
> + HANTRO_PP_REG_WRITE(vpu, input_fmt, src_pp_fmt);
> + HANTRO_PP_REG_WRITE(vpu, output_fmt, dst_pp_fmt);
> + HANTRO_PP_REG_WRITE(vpu, output_width, ctx->dst_fmt.width);
> + HANTRO_PP_REG_WRITE(vpu, output_height, ctx->dst_fmt.height);
> + HANTRO_PP_REG_WRITE(vpu, orig_width, MB_WIDTH(ctx->dst_fmt.width));
> + HANTRO_PP_REG_WRITE(vpu, display_width, ctx->dst_fmt.width);
> +}
> +
> +void hantro_postproc_free(struct hantro_ctx *ctx)
> +{
> + struct hantro_dev *vpu = ctx->dev;
> + unsigned int i;
> +
> + for (i = 0; i < VB2_MAX_FRAME; ++i) {
> + struct hantro_aux_buf *priv = &ctx->postproc.dec_q[i];
> +
> + if (priv->cpu) {
> + dma_free_attrs(vpu->dev, priv->size, priv->cpu,
> + priv->dma, priv->attrs);
> + priv->cpu = NULL;
> + }
> + }
> +}
> +
> +int hantro_postproc_alloc(struct hantro_ctx *ctx)
> +{
> + struct hantro_dev *vpu = ctx->dev;
> + unsigned int i, buf_size;
> +
> + buf_size = ctx->dst_fmt.plane_fmt[0].sizeimage;
> +
> + for (i = 0; i < VB2_MAX_FRAME; ++i) {

If requests less than VB2_MAX_FRAME capture frames, some of those are
unused. I think it would be better to match the amount of capture frames
here.

> + struct hantro_aux_buf *priv = &ctx->postproc.dec_q[i];
> +
> + /*
> + * The buffers on this queue are meant as intermediate
> + * buffers for the decoder, so no mapping is needed.
> + */
> + priv->attrs = DMA_ATTR_NO_KERNEL_MAPPING;
> + priv->cpu = dma_alloc_attrs(vpu->dev, buf_size, &priv->dma,
> + GFP_KERNEL, priv->attrs);
> + if (!priv->cpu)
> + return -ENOMEM;
> + priv->size = buf_size;
> + }
> + return 0;
> +}
> +
> +void hantro_postproc_disable(struct hantro_ctx *ctx)
> +{
> + struct hantro_dev *vpu = ctx->dev;
> +
> + HANTRO_PP_REG_WRITE_S(vpu, pipeline_en, 0x0);
> +}
> diff --git a/drivers/staging/media/hantro/hantro_v4l2.c b/drivers/staging/media/hantro/hantro_v4l2.c
> index 238e53b28f8f..ff665d4f004f 100644
> --- a/drivers/staging/media/hantro/hantro_v4l2.c
> +++ b/drivers/staging/media/hantro/hantro_v4l2.c
> @@ -46,6 +46,19 @@ hantro_get_formats(const struct hantro_ctx *ctx, unsigned int *num_fmts)
> return formats;
> }
>
> +static const struct hantro_fmt *
> +hantro_get_postproc_formats(const struct hantro_ctx *ctx,
> + unsigned int *num_fmts)
> +{
> + if (hantro_is_encoder_ctx(ctx)) {
> + *num_fmts = 0;
> + return NULL;
> + }
> +
> + *num_fmts = ctx->dev->variant->num_postproc_fmts;
> + return ctx->dev->variant->postproc_fmts;
> +}
> +
> static const struct hantro_fmt *
> hantro_find_format(const struct hantro_ctx *ctx, u32 fourcc)
> {
> @@ -57,6 +70,10 @@ hantro_find_format(const struct hantro_ctx *ctx, u32 fourcc)
> if (formats[i].fourcc == fourcc)
> return &formats[i];
>
> + formats = hantro_get_postproc_formats(ctx, &num_fmts);
> + for (i = 0; i < num_fmts; i++)
> + if (formats[i].fourcc == fourcc)
> + return &formats[i];
> return NULL;
> }
>
> @@ -151,6 +168,20 @@ static int vidioc_enum_fmt(struct file *file, void *priv,
> }
> ++j;
> }
> +
> + /* Enumerate post-processed formats. */

I think here some of the explanation from the commit message of patch 3
could be added: why the driver is enumerating PP formats after non-PP
formats.

> + if (!capture)
> + return -EINVAL;
> + formats = hantro_get_postproc_formats(ctx, &num_fmts);
> + for (i = 0; i < num_fmts; i++) {
> + if (j == f->index) {
> + fmt = &formats[i];
> + f->pixelformat = fmt->fourcc;
> + return 0;
> + }
> + ++j;
> + }
> +
> return -EINVAL;
> }
>
> @@ -241,9 +272,10 @@ static int vidioc_try_fmt(struct file *file, void *priv, struct v4l2_format *f,
> /*
> * The H264 decoder needs extra space on the output buffers
> * to store motion vectors. This is needed for reference
> - * frames.
> + * frames and only if the format is non-post-processed (NV12).
> */
> - if (ctx->vpu_src_fmt->fourcc == V4L2_PIX_FMT_H264_SLICE)
> + if (ctx->vpu_src_fmt->fourcc == V4L2_PIX_FMT_H264_SLICE &&
> + fmt->fourcc == V4L2_PIX_FMT_NV12)

If you change hantro_needs_postproc to use a struct hantro_fmt argument,
you could use hantro_needs_postproc(fmt) here.

> pix_mp->plane_fmt[0].sizeimage +=
> 128 * DIV_ROUND_UP(pix_mp->width, 16) *
> DIV_ROUND_UP(pix_mp->height, 16);
> @@ -611,10 +643,23 @@ static int hantro_start_streaming(struct vb2_queue *q, unsigned int count)
>
> vpu_debug(4, "Codec mode = %d\n", codec_mode);
> ctx->codec_ops = &ctx->dev->variant->codec_ops[codec_mode];
> - if (ctx->codec_ops->init)
> + if (ctx->codec_ops->init) {
> ret = ctx->codec_ops->init(ctx);
> + if (ret)
> + return ret;
> + }
> +
> + if (hantro_needs_postproc(ctx)) {
> + ret = hantro_postproc_alloc(ctx);

Why is this done in start_streaming? Wouldn't capture side REQBUFS be a
better place for this?

> + if (ret)
> + goto err_codec_exit;
> + }
> }
> + return ret;
>
> +err_codec_exit:
> + if (ctx->codec_ops && ctx->codec_ops->exit)
> + ctx->codec_ops->exit(ctx);
> return ret;
> }
>
> @@ -641,6 +686,7 @@ static void hantro_stop_streaming(struct vb2_queue *q)
> struct hantro_ctx *ctx = vb2_get_drv_priv(q);
>
> if (hantro_vq_is_coded(q)) {
> + hantro_postproc_free(ctx);

Same as above, move this to capture side REQBUFS(0) ?

> if (ctx->codec_ops && ctx->codec_ops->exit)
> ctx->codec_ops->exit(ctx);
> }
> diff --git a/drivers/staging/media/hantro/rk3288_vpu_hw.c b/drivers/staging/media/hantro/rk3288_vpu_hw.c
> index f8db6fcaad73..2f914b37b9e5 100644
> --- a/drivers/staging/media/hantro/rk3288_vpu_hw.c
> +++ b/drivers/staging/media/hantro/rk3288_vpu_hw.c
> @@ -56,6 +56,13 @@ static const struct hantro_fmt rk3288_vpu_enc_fmts[] = {
> },
> };
>
> +static const struct hantro_fmt rk3288_vpu_postproc_fmts[] = {
> + {
> + .fourcc = V4L2_PIX_FMT_YUYV,
> + .codec_mode = HANTRO_MODE_NONE,
> + },
> +};
> +
> static const struct hantro_fmt rk3288_vpu_dec_fmts[] = {
> {
> .fourcc = V4L2_PIX_FMT_NV12,
> @@ -215,6 +222,9 @@ const struct hantro_variant rk3288_vpu_variant = {
> .dec_offset = 0x400,
> .dec_fmts = rk3288_vpu_dec_fmts,
> .num_dec_fmts = ARRAY_SIZE(rk3288_vpu_dec_fmts),
> + .postproc_fmts = rk3288_vpu_postproc_fmts,
> + .num_postproc_fmts = ARRAY_SIZE(rk3288_vpu_postproc_fmts),
> + .postproc_regs = &hantro_g1_postproc_regs,
> .codec = HANTRO_JPEG_ENCODER | HANTRO_MPEG2_DECODER |
> HANTRO_VP8_DECODER | HANTRO_H264_DECODER,
> .codec_ops = rk3288_vpu_codec_ops,

regards
Philipp