media: uapi: h264: Increase size of DPB entry pic_num

DPB entry PicNum maximum value is 2*MaxFrameNum for interlaced
content (field_pic_flag=1).

As specified, MaxFrameNum is 2^(log2_max_frame_num_minus4 + 4)
and log2_max_frame_num_minus4 is in the range of 0 to 12,
which means pic_num should be a 32-bit field.

The v4l2_h264_dpb_entry struct needs to be padded to avoid a hole,
which might be also useful to allow future uAPI extensions.

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Tested-by: Jonas Karlman <jonas@kwiboo.se>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

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

@@ -2051,15 +2051,18 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type -
         ``timestamp`` field in struct :c:type:`v4l2_buffer`. Use the
         :c:func:`v4l2_timeval_to_ns()` function to convert the struct
         :c:type:`timeval` in struct :c:type:`v4l2_buffer` to a __u64.
-    * - __u16
+    * - __u32
-      - ``frame_num``
+      - ``pic_num``
       -
     * - __u16
-      - ``pic_num``
+      - ``frame_num``
       -
     * - __u8
       - ``fields``
       - Specifies how the DPB entry is referenced. See :ref:`Reference Fields <h264_ref_fields>`
+    * - __u8
+      - ``reserved[5]``
+      - Applications and drivers must set this to zero.
     * - __s32
       - ``top_field_order_cnt``
       -

drivers/media/v4l2-core/v4l2-ctrls.c

@@ -1725,6 +1725,8 @@ static void std_log(const struct v4l2_ctrl *ctrl)
 
 #define zero_padding(s) \
 	memset(&(s).padding, 0, sizeof((s).padding))
+#define zero_reserved(s) \
+	memset(&(s).reserved, 0, sizeof((s).reserved))
 
 /*
  * Compound controls validation requires setting unused fields/flags to zero
@@ -1735,6 +1737,7 @@ static int std_validate_compound(const struct v4l2_ctrl *ctrl, u32 idx,
 {
 	struct v4l2_ctrl_mpeg2_slice_params *p_mpeg2_slice_params;
 	struct v4l2_ctrl_vp8_frame_header *p_vp8_frame_header;
+	struct v4l2_ctrl_h264_decode_params *p_h264_dec_params;
 	struct v4l2_ctrl_hevc_sps *p_hevc_sps;
 	struct v4l2_ctrl_hevc_pps *p_hevc_pps;
 	struct v4l2_ctrl_hevc_slice_params *p_hevc_slice_params;
@@ -1796,7 +1799,17 @@ static int std_validate_compound(const struct v4l2_ctrl *ctrl, u32 idx,
 	case V4L2_CTRL_TYPE_H264_SCALING_MATRIX:
 	case V4L2_CTRL_TYPE_H264_PRED_WEIGHTS:
 	case V4L2_CTRL_TYPE_H264_SLICE_PARAMS:
+		break;
+
 	case V4L2_CTRL_TYPE_H264_DECODE_PARAMS:
+		p_h264_dec_params = p;
+
+		for (i = 0; i < V4L2_H264_NUM_DPB_ENTRIES; i++) {
+			struct v4l2_h264_dpb_entry *dpb_entry =
+				&p_h264_dec_params->dpb[i];
+
+			zero_reserved(*dpb_entry);
+		}
 		break;
 
 	case V4L2_CTRL_TYPE_VP8_FRAME_HEADER:

include/media/h264-ctrls.h

@@ -213,9 +213,10 @@ struct v4l2_ctrl_h264_slice_params {
 
 struct v4l2_h264_dpb_entry {
 	__u64 reference_ts;
+	__u32 pic_num;
 	__u16 frame_num;
-	__u16 pic_num;
 	__u8 fields;
+	__u8 reserved[5];
 	/* Note that field is indicated by v4l2_buffer.field */
 	__s32 top_field_order_cnt;
 	__s32 bottom_field_order_cnt;

include/media/v4l2-h264.h

@@ -33,7 +33,7 @@ struct v4l2_h264_reflist_builder {
 	struct {
 		s32 pic_order_count;
 		int frame_num;
-		u16 pic_num;
+		u32 pic_num;
 		u16 longterm : 1;
 	} refs[V4L2_H264_NUM_DPB_ENTRIES];
 	s32 cur_pic_order_count;