[PATCH] media: imx-jpeg: Account for data_offset when getting image address

[Ming Qian(OSS)]

Hi Nicolas,

On 2025/5/2 1:02, Nicolas Dufresne wrote:
> Le mercredi 30 avril 2025 à 13:39 +0800, ming.qian at oss.nxp.com a écrit :
>> From: Ming Qian <ming.qian at nxp.com>
>>
>> Applications may set data_offset when it refers to an output queue. So
>> driver need to account for it when getting the start address of input
>> image in the plane.
>>
>> Meanwhile data_offset is included in bytesused. So the data_offset
>> should be subtracted from the payload of input image.
> 
> I think you should revisit this commit message a little in the next version.
> While the overall patch looks good, I believe you forgot to add code to verify
> that addr + data_offset still falls within the HW needed alignment. I don't
> have the HW documentation for that chip, but I have never seen HW capapble of
> handlign random alignment.
> 
> Without the data_offset, the data is always page align, so we don't usually
> have to validate that.
> 
> regards,
> Nicolas
> 

Thanks for the reminder, the mxc-jpeg codec requires addresses to be
16-aligned. I'll fix it in v2.

Regards,
Ming

>>
>> Signed-off-by: Ming Qian <ming.qian at nxp.com>
>> ---
>>   .../media/platform/nxp/imx-jpeg/mxc-jpeg.c    | 42 ++++++++++++++-----
>>   1 file changed, 31 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.c b/drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.c
>> index 1221b309a916..035368d65913 100644
>> --- a/drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.c
>> +++ b/drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.c
>> @@ -587,6 +587,27 @@ static void _bswap16(u16 *a)
>>   	*a = ((*a & 0x00FF) << 8) | ((*a & 0xFF00) >> 8);
>>   }
>>   
>> +static dma_addr_t mxc_jpeg_get_plane_dma_addr(struct vb2_buffer *buf, unsigned int plane_no)
>> +{
>> +	if (plane_no >= buf->num_planes)
>> +		return 0;
>> +	return vb2_dma_contig_plane_dma_addr(buf, plane_no) + buf->planes[plane_no].data_offset;
>> +}
>> +
>> +static void *mxc_jpeg_get_plane_vaddr(struct vb2_buffer *buf, unsigned int plane_no)
>> +{
>> +	if (plane_no >= buf->num_planes)
>> +		return NULL;
>> +	return vb2_plane_vaddr(buf, plane_no) + buf->planes[plane_no].data_offset;
>> +}
>> +
>> +static unsigned long mxc_jpeg_get_plane_payload(struct vb2_buffer *buf, unsigned int plane_no)
>> +{
>> +	if (plane_no >= buf->num_planes)
>> +		return 0;
>> +	return vb2_get_plane_payload(buf, plane_no) - buf->planes[plane_no].data_offset;
>> +}
>> +
>>   static void print_mxc_buf(struct mxc_jpeg_dev *jpeg, struct vb2_buffer *buf,
>>   			  unsigned long len)
>>   {
>> @@ -599,11 +620,11 @@ static void print_mxc_buf(struct mxc_jpeg_dev *jpeg, struct vb2_buffer *buf,
>>   		return;
>>   
>>   	for (plane_no = 0; plane_no < buf->num_planes; plane_no++) {
>> -		payload = vb2_get_plane_payload(buf, plane_no);
>> +		payload = mxc_jpeg_get_plane_payload(buf, plane_no);
>>   		if (len == 0)
>>   			len = payload;
>> -		dma_addr = vb2_dma_contig_plane_dma_addr(buf, plane_no);
>> -		vaddr = vb2_plane_vaddr(buf, plane_no);
>> +		dma_addr = mxc_jpeg_get_plane_dma_addr(buf, plane_no);
>> +		vaddr = mxc_jpeg_get_plane_vaddr(buf, plane_no);
>>   		v4l2_dbg(3, debug, &jpeg->v4l2_dev,
>>   			 "plane %d (vaddr=%p dma_addr=%x payload=%ld):",
>>   			  plane_no, vaddr, dma_addr, payload);
>> @@ -701,16 +722,15 @@ static void mxc_jpeg_addrs(struct mxc_jpeg_desc *desc,
>>   	struct mxc_jpeg_q_data *q_data;
>>   
>>   	q_data = mxc_jpeg_get_q_data(ctx, raw_buf->type);
>> -	desc->buf_base0 = vb2_dma_contig_plane_dma_addr(raw_buf, 0);
>> +	desc->buf_base0 = mxc_jpeg_get_plane_dma_addr(raw_buf, 0);
>>   	desc->buf_base1 = 0;
>>   	if (img_fmt == STM_CTRL_IMAGE_FORMAT(MXC_JPEG_YUV420)) {
>>   		if (raw_buf->num_planes == 2)
>> -			desc->buf_base1 = vb2_dma_contig_plane_dma_addr(raw_buf, 1);
>> +			desc->buf_base1 = mxc_jpeg_get_plane_dma_addr(raw_buf, 1);
>>   		else
>>   			desc->buf_base1 = desc->buf_base0 + q_data->sizeimage[0];
>>   	}
>> -	desc->stm_bufbase = vb2_dma_contig_plane_dma_addr(jpeg_buf, 0) +
>> -		offset;
>> +	desc->stm_bufbase = mxc_jpeg_get_plane_dma_addr(jpeg_buf, 0) + offset;
>>   }
>>   
>>   static bool mxc_jpeg_is_extended_sequential(const struct mxc_jpeg_fmt *fmt)
>> @@ -967,8 +987,8 @@ static irqreturn_t mxc_jpeg_dec_irq(int irq, void *priv)
>>   			vb2_set_plane_payload(&dst_buf->vb2_buf, 1, payload);
>>   		}
>>   		dev_dbg(dev, "Decoding finished, payload size: %ld + %ld\n",
>> -			vb2_get_plane_payload(&dst_buf->vb2_buf, 0),
>> -			vb2_get_plane_payload(&dst_buf->vb2_buf, 1));
>> +			mxc_jpeg_get_plane_payload(&dst_buf->vb2_buf, 0),
>> +			mxc_jpeg_get_plane_payload(&dst_buf->vb2_buf, 1));
>>   	}
>>   
>>   	/* short preview of the results */
>> @@ -1827,8 +1847,8 @@ static int mxc_jpeg_parse(struct mxc_jpeg_ctx *ctx, struct vb2_buffer *vb)
>>   	struct mxc_jpeg_sof *psof = NULL;
>>   	struct mxc_jpeg_sos *psos = NULL;
>>   	struct mxc_jpeg_src_buf *jpeg_src_buf = vb2_to_mxc_buf(vb);
>> -	u8 *src_addr = (u8 *)vb2_plane_vaddr(vb, 0);
>> -	u32 size = vb2_get_plane_payload(vb, 0);
>> +	u8 *src_addr = (u8 *)mxc_jpeg_get_plane_vaddr(vb, 0);
>> +	u32 size = mxc_jpeg_get_plane_payload(vb, 0);
>>   	int ret;
>>   
>>   	memset(&header, 0, sizeof(header));
>>
>> base-commit: 0af2f6be1b4281385b618cb86ad946eded089ac8
>> prerequisite-patch-id: 0000000000000000000000000000000000000000