Re: [PATCH v2 2/3] media: imx-jpeg: Change the pattern size to 128x64

Frank Li
2025-03-28T14:29:09Z

On Fri, Mar 28, 2025 at 02:30:51PM +0800, ming.qian@oss.nxp.com wrote:
> From: Ming Qian <ming.qian@oss.nxp.com>
>
> To support decoding motion-jpeg without DHT, driver will try to decode a
> pattern jpeg before actual jpeg frame by use of linked descriptors
> (This is called "repeat mode"), then the DHT in the pattern jpeg can be
> used for decoding the motion-jpeg.
>
> To avoid performance loss, use the smallest supported resolution 64x64
> as the pattern jpeg size.
>
> But there is a hardware issue: when the JPEG decoded frame with a
> resolution that is no larger than 64x64 and it is followed by a next
> decoded frame with a larger resolution but not 64 aligned, then this
> next decoded frame may be corrupted.
>
> To avoid corruption of the decoded image, we change the pattern jpeg
> size to 128x64, as we confirmed with the hardware designer that this is
> a safe size.
>
> Besides, we also need to allocate a dma buffer to store the decoded
> picture for the pattern image.
>
> Signed-off-by: Ming Qian <ming.qian@oss.nxp.com>
> ---

Reviewed-by: Frank Li <Frank.Li@nxp.com>

> .../media/platform/nxp/imx-jpeg/mxc-jpeg.c | 42 +++++++++++++++----
> .../media/platform/nxp/imx-jpeg/mxc-jpeg.h | 5 +++
> 2 files changed, 39 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.c b/drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.c
> index 12661c177f5a..45705c606769 100644
> --- a/drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.c
> +++ b/drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.c
> @@ -535,7 +535,18 @@ static const unsigned char jpeg_sos_maximal[] = {
> };
>
> static const unsigned char jpeg_image_red[] = {
> - 0xFC, 0x5F, 0xA2, 0xBF, 0xCA, 0x73, 0xFE, 0xFE,
> + 0xF9, 0xFE, 0x8A, 0xFC, 0x34, 0xFD, 0xC4, 0x28,
> + 0xA0, 0x02, 0x8A, 0x00, 0x28, 0xA0, 0x02, 0x8A,
> + 0x00, 0x28, 0xA0, 0x02, 0x8A, 0x00, 0x28, 0xA0,
> + 0x02, 0x8A, 0x00, 0x28, 0xA0, 0x02, 0x8A, 0x00,
> + 0x28, 0xA0, 0x02, 0x8A, 0x00, 0x28, 0xA0, 0x02,
> + 0x8A, 0x00, 0x28, 0xA0, 0x02, 0x8A, 0x00, 0x28,
> + 0xA0, 0x02, 0x8A, 0x00, 0x28, 0xA0, 0x02, 0x8A,
> + 0x00, 0x28, 0xA0, 0x02, 0x8A, 0x00, 0x28, 0xA0,
> + 0x02, 0x8A, 0x00, 0x28, 0xA0, 0x02, 0x8A, 0x00,
> + 0x28, 0xA0, 0x02, 0x8A, 0x00, 0x28, 0xA0, 0x02,
> + 0x8A, 0x00, 0x28, 0xA0, 0x0F, 0xFF, 0xD0, 0xF9,
> + 0xFE, 0x8A, 0xFC, 0x34, 0xFD, 0xC4, 0x28, 0xA0,
> 0x02, 0x8A, 0x00, 0x28, 0xA0, 0x02, 0x8A, 0x00,
> 0x28, 0xA0, 0x02, 0x8A, 0x00, 0x28, 0xA0, 0x02,
> 0x8A, 0x00, 0x28, 0xA0, 0x02, 0x8A, 0x00, 0x28,
> @@ -545,7 +556,7 @@ static const unsigned char jpeg_image_red[] = {
> 0x28, 0xA0, 0x02, 0x8A, 0x00, 0x28, 0xA0, 0x02,
> 0x8A, 0x00, 0x28, 0xA0, 0x02, 0x8A, 0x00, 0x28,
> 0xA0, 0x02, 0x8A, 0x00, 0x28, 0xA0, 0x02, 0x8A,
> - 0x00, 0x28, 0xA0, 0x02, 0x8A, 0x00
> + 0x00, 0x28, 0xA0, 0x0F
> };
>
> static const unsigned char jpeg_eoi[] = {
> @@ -775,6 +786,13 @@ static void mxc_jpeg_free_slot_data(struct mxc_jpeg_dev *jpeg)
> jpeg->slot_data.cfg_stream_vaddr = NULL;
> jpeg->slot_data.cfg_stream_handle = 0;
>
> + dma_free_coherent(jpeg->dev, jpeg->slot_data.cfg_dec_size,
> + jpeg->slot_data.cfg_dec_vaddr,
> + jpeg->slot_data.cfg_dec_daddr);
> + jpeg->slot_data.cfg_dec_size = 0;
> + jpeg->slot_data.cfg_dec_vaddr = NULL;
> + jpeg->slot_data.cfg_dec_daddr = 0;
> +
> jpeg->slot_data.used = false;
> }
>
> @@ -814,6 +832,14 @@ static bool mxc_jpeg_alloc_slot_data(struct mxc_jpeg_dev *jpeg)
> goto err;
> jpeg->slot_data.cfg_stream_vaddr = cfg_stm;
>
> + jpeg->slot_data.cfg_dec_size = MXC_JPEG_PATTERN_WIDTH * MXC_JPEG_PATTERN_HEIGHT * 2;
> + jpeg->slot_data.cfg_dec_vaddr = dma_alloc_coherent(jpeg->dev,
> + jpeg->slot_data.cfg_dec_size,
> + &jpeg->slot_data.cfg_dec_daddr,
> + GFP_ATOMIC);
> + if (!jpeg->slot_data.cfg_dec_vaddr)
> + goto err;
> +
> skip_alloc:
> jpeg->slot_data.used = true;
>
> @@ -1216,14 +1242,14 @@ static void mxc_jpeg_config_dec_desc(struct vb2_buffer *out_buf,
> */
> *cfg_size = mxc_jpeg_setup_cfg_stream(cfg_stream_vaddr,
> V4L2_PIX_FMT_YUYV,
> - MXC_JPEG_MIN_WIDTH,
> - MXC_JPEG_MIN_HEIGHT);
> + MXC_JPEG_PATTERN_WIDTH,
> + MXC_JPEG_PATTERN_HEIGHT);
> cfg_desc->next_descpt_ptr = desc_handle | MXC_NXT_DESCPT_EN;
> - cfg_desc->buf_base0 = vb2_dma_contig_plane_dma_addr(dst_buf, 0);
> + cfg_desc->buf_base0 = jpeg->slot_data.cfg_dec_daddr;
> cfg_desc->buf_base1 = 0;
> - cfg_desc->imgsize = MXC_JPEG_MIN_WIDTH << 16;
> - cfg_desc->imgsize |= MXC_JPEG_MIN_HEIGHT;
> - cfg_desc->line_pitch = MXC_JPEG_MIN_WIDTH * 2;
> + cfg_desc->imgsize = MXC_JPEG_PATTERN_WIDTH << 16;
> + cfg_desc->imgsize |= MXC_JPEG_PATTERN_HEIGHT;
> + cfg_desc->line_pitch = MXC_JPEG_PATTERN_WIDTH * 2;
> cfg_desc->stm_ctrl = STM_CTRL_IMAGE_FORMAT(MXC_JPEG_YUV422);
> cfg_desc->stm_ctrl |= STM_CTRL_BITBUF_PTR_CLR(1);
> cfg_desc->stm_bufbase = cfg_stream_handle;
> diff --git a/drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.h b/drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.h
> index 86e324b21aed..fdde45f7e163 100644
> --- a/drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.h
> +++ b/drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.h
> @@ -28,6 +28,8 @@
> #define MXC_JPEG_W_ALIGN 3
> #define MXC_JPEG_MAX_SIZEIMAGE 0xFFFFFC00
> #define MXC_JPEG_MAX_PLANES 2
> +#define MXC_JPEG_PATTERN_WIDTH 128
> +#define MXC_JPEG_PATTERN_HEIGHT 64
>
> enum mxc_jpeg_enc_state {
> MXC_JPEG_ENCODING = 0, /* jpeg encode phase */
> @@ -117,6 +119,9 @@ struct mxc_jpeg_slot_data {
> dma_addr_t desc_handle;
> dma_addr_t cfg_desc_handle; // configuration descriptor dma address
> dma_addr_t cfg_stream_handle; // configuration bitstream dma address
> + dma_addr_t cfg_dec_size;
> + void *cfg_dec_vaddr;
> + dma_addr_t cfg_dec_daddr;
> };
>
> struct mxc_jpeg_dev {
> --
> 2.43.0-rc1
>