media: uapi: Change data_bit_offset definition

'F.7.3.6.1 General slice segment header syntax' section of HEVC
specification describes that a slice header always end aligned on
byte boundary, therefore we only need to provide the data offset in bytes.
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
Reviewed-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Acked-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Tested-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst

@@ -3008,8 +3008,8 @@ enum v4l2_mpeg_video_hevc_size_of_length_field -
       - ``bit_size``
       - Size (in bits) of the current slice data.
     * - __u32
-      - ``data_bit_offset``
-      - Offset (in bits) to the video data in the current slice data.
+      - ``data_byte_offset``
+      - Offset (in bytes) to the video data in the current slice data.
     * - __u32
       - ``num_entry_point_offsets``
       - Specifies the number of entry point offset syntax elements in the slice header.

drivers/staging/media/sunxi/cedrus/cedrus_h265.c

@@ -317,6 +317,8 @@ static void cedrus_h265_setup(struct cedrus_ctx *ctx,
 	u32 chroma_log2_weight_denom;
 	u32 output_pic_list_index;
 	u32 pic_order_cnt[2];
+	u8 *padding;
+	int count;
 	u32 reg;
 
 	sps = run->h265.sps;
@@ -405,7 +407,22 @@ static void cedrus_h265_setup(struct cedrus_ctx *ctx,
 	/* Initialize bitstream access. */
 	cedrus_write(dev, VE_DEC_H265_TRIGGER, VE_DEC_H265_TRIGGER_INIT_SWDEC);
 
-	cedrus_h265_skip_bits(dev, slice_params->data_bit_offset);
+	/*
+	 * Cedrus expects that bitstream pointer is actually at the end of the slice header
+	 * instead of start of slice data. Padding is 8 bits at most (one bit set to 1 and
+	 * at most seven bits set to 0), so we have to inspect only one byte before slice data.
+	 */
+	padding = (u8 *)vb2_plane_vaddr(&run->src->vb2_buf, 0) +
+		slice_params->data_byte_offset - 1;
+
+	for (count = 0; count < 8; count++)
+		if (*padding & (1 << count))
+			break;
+
+	/* Include the one bit. */
+	count++;
+
+	cedrus_h265_skip_bits(dev, slice_params->data_byte_offset * 8 - count);
 
 	/* Bitstream parameters. */
 

drivers/staging/media/sunxi/cedrus/cedrus_video.c

@@ -568,7 +568,6 @@ int cedrus_queue_init(void *priv, struct vb2_queue *src_vq,
 
 	src_vq->type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
 	src_vq->io_modes = VB2_MMAP | VB2_DMABUF;
-	src_vq->dma_attrs = DMA_ATTR_NO_KERNEL_MAPPING;
 	src_vq->drv_priv = ctx;
 	src_vq->buf_struct_size = sizeof(struct cedrus_buffer);
 	src_vq->ops = &cedrus_qops;

include/media/hevc-ctrls.h

@@ -310,7 +310,7 @@ struct v4l2_hevc_pred_weight_table {
  * V4L2_CTRL_FLAG_DYNAMIC_ARRAY flag must be set when using it.
  *
  * @bit_size: size (in bits) of the current slice data
- * @data_bit_offset: offset (in bits) to the video data in the current slice data
+ * @data_byte_offset: offset (in bytes) to the video data in the current slice data
  * @num_entry_point_offsets: specifies the number of entry point offset syntax
  *			     elements in the slice header.
  * @nal_unit_type: specifies the coding type of the slice (B, P or I)
@@ -356,7 +356,7 @@ struct v4l2_hevc_pred_weight_table {
  */
 struct v4l2_ctrl_hevc_slice_params {
 	__u32	bit_size;
-	__u32	data_bit_offset;
+	__u32	data_byte_offset;
 	__u32	num_entry_point_offsets;
 	/* ISO/IEC 23008-2, ITU-T Rec. H.265: NAL unit header */
 	__u8	nal_unit_type;