media: cedrus: fix various format-related compliance issues

Initialize the context on open() with valid capture and output
formats. It is good practice to always have valid formats internally.

This solves one vb2 warning in the kernel log where the sizeimage
value of the output format was 0 when requesting buffers, which is
not allowed.

It also simplifies the g_fmt ioctl implementations since they no longer
have to check if a valid format was ever set.

cedrus_prepare_format() now also validates sizeimage for the output
formats, ensuring userspace can't set it to 0 since that would cause
the same vb2 warning.

Finally remove the sizeimage == 0 check in cedrus_try_fmt_vid_out()
since cedrus_prepare_format() will now adjust this value.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reviewed-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

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

@@ -241,6 +241,16 @@ static int cedrus_open(struct file *file)
 		ret = PTR_ERR(ctx->fh.m2m_ctx);
 		goto err_ctrls;
 	}
+	ctx->dst_fmt.pixelformat = V4L2_PIX_FMT_SUNXI_TILED_NV12;
+	cedrus_prepare_format(&ctx->dst_fmt);
+	ctx->src_fmt.pixelformat = V4L2_PIX_FMT_MPEG2_SLICE;
+	/*
+	 * TILED_NV12 has more strict requirements, so copy the width and
+	 * height to src_fmt to ensure that is matches the dst_fmt resolution.
+	 */
+	ctx->src_fmt.width = ctx->dst_fmt.width;
+	ctx->src_fmt.height = ctx->dst_fmt.height;
+	cedrus_prepare_format(&ctx->src_fmt);
 
 	v4l2_fh_add(&ctx->fh);
 

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

@@ -86,7 +86,7 @@ static struct cedrus_format *cedrus_find_format(u32 pixelformat, u32 directions,
 	return &cedrus_formats[i];
 }
 
-static void cedrus_prepare_format(struct v4l2_pix_format *pix_fmt)
+void cedrus_prepare_format(struct v4l2_pix_format *pix_fmt)
 {
 	unsigned int width = pix_fmt->width;
 	unsigned int height = pix_fmt->height;
@@ -104,7 +104,8 @@ static void cedrus_prepare_format(struct v4l2_pix_format *pix_fmt)
 	case V4L2_PIX_FMT_H264_SLICE:
 		/* Zero bytes per line for encoded source. */
 		bytesperline = 0;
-
+		/* Choose some minimum size since this can't be 0 */
+		sizeimage = max_t(u32, SZ_1K, sizeimage);
 		break;
 
 	case V4L2_PIX_FMT_SUNXI_TILED_NV12:
@@ -211,16 +212,7 @@ static int cedrus_g_fmt_vid_cap(struct file *file, void *priv,
 {
 	struct cedrus_ctx *ctx = cedrus_file2ctx(file);
 
-	/* Fall back to dummy default by lack of hardware configuration. */
-	if (!ctx->dst_fmt.width || !ctx->dst_fmt.height) {
-		f->fmt.pix.pixelformat = V4L2_PIX_FMT_SUNXI_TILED_NV12;
-		cedrus_prepare_format(&f->fmt.pix);
-
-		return 0;
-	}
-
 	f->fmt.pix = ctx->dst_fmt;
-
 	return 0;
 }
 
@@ -229,17 +221,7 @@ static int cedrus_g_fmt_vid_out(struct file *file, void *priv,
 {
 	struct cedrus_ctx *ctx = cedrus_file2ctx(file);
 
-	/* Fall back to dummy default by lack of hardware configuration. */
-	if (!ctx->dst_fmt.width || !ctx->dst_fmt.height) {
-		f->fmt.pix.pixelformat = V4L2_PIX_FMT_MPEG2_SLICE;
-		f->fmt.pix.sizeimage = SZ_1K;
-		cedrus_prepare_format(&f->fmt.pix);
-
-		return 0;
-	}
-
 	f->fmt.pix = ctx->src_fmt;
-
 	return 0;
 }
 
@@ -275,10 +257,6 @@ static int cedrus_try_fmt_vid_out(struct file *file, void *priv,
 	if (!fmt)
 		return -EINVAL;
 
-	/* Source image size has to be provided by userspace. */
-	if (pix_fmt->sizeimage == 0)
-		return -EINVAL;
-
 	pix_fmt->pixelformat = fmt->pixelformat;
 	cedrus_prepare_format(pix_fmt);
 

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

@@ -26,5 +26,6 @@ extern const struct v4l2_ioctl_ops cedrus_ioctl_ops;
 
 int cedrus_queue_init(void *priv, struct vb2_queue *src_vq,
 		      struct vb2_queue *dst_vq);
+void cedrus_prepare_format(struct v4l2_pix_format *pix_fmt);
 
 #endif