From e1ad27027587cc9ea03889c63d9d402a61d8e553 Mon Sep 17 00:00:00 2001 From: Ricardo Ribalda Date: Mon, 7 Jul 2025 18:34:02 +0000 Subject: [PATCH] media: Documentation: Add note about UVCH length field The documentation currently describes the UVC length field as the "length of the rest of the block", which can be misleading. The driver limits the data copied to a maximum of 12 bytes. This change adds a clarifying sentence to the documentation to make this restriction explicit. Reviewed-by: Hans de Goede Signed-off-by: Ricardo Ribalda Link: https://lore.kernel.org/r/20250707-uvc-meta-v8-2-ed17f8b1218b@chromium.org Signed-off-by: Hans de Goede Signed-off-by: Hans Verkuil --- Documentation/userspace-api/media/v4l/metafmt-uvc.rst | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/Documentation/userspace-api/media/v4l/metafmt-uvc.rst b/Documentation/userspace-api/media/v4l/metafmt-uvc.rst index 784346d14bbdb..4c05e9e54683a 100644 --- a/Documentation/userspace-api/media/v4l/metafmt-uvc.rst +++ b/Documentation/userspace-api/media/v4l/metafmt-uvc.rst @@ -44,7 +44,9 @@ Each individual block contains the following fields: them * - :cspan:`1` *The rest is an exact copy of the UVC payload header:* * - __u8 length; - - length of the rest of the block, including this field + - length of the rest of the block, including this field. Please note that + regardless of this value, for V4L2_META_FMT_UVC the kernel will never + copy more than 2-12 bytes. * - __u8 flags; - Flags, indicating presence of other standard UVC fields * - __u8 buf[]; -- 2.47.2