RE: [PATCH v3 2/2] usb: webcam: Invalid size of Processing Unit Descriptor

From: Pawel Laszczak <pawell@cadence.com>

According with USB Device Class Definition for Video Device the
Processing Unit Descriptor bLength should be 12 (10 + bmControlSize),
but it has 11.

Invalid length caused that Processing Unit Descriptor Test Video form
CV tool failed. To fix this issue patch adds bmVideoStandards into
uvc_processing_unit_descriptor structure.

The bmVideoStandards field was added in UVC 1.1 and it wasn't part of
UVC 1.0a.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Pawel Laszczak <pawell@cadence.com>

---
Changelog:
v3:
- updated the commit message
- added bmVideoStandard field to UVC gadget driver
v2:
- updated UVC_DT_PROCESSING_UNIT_SIZE macro

drivers/usb/gadget/function/f_uvc.c | 1 +
drivers/usb/gadget/legacy/webcam.c  | 1 +
include/uapi/linux/usb/video.h      | 3 ++-
3 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c
index 5d62720bb9e1..e3b0a79c8f01 100644
--- a/drivers/usb/gadget/function/f_uvc.c
+++ b/drivers/usb/gadget/function/f_uvc.c

@@ -823,6 +823,7 @@ static struct usb_function_instance *uvc_alloc_inst(void)

	pd->bmControls[0]		= 1;
	pd->bmControls[1]		= 0;
	pd->iProcessing			= 0;
+	pd->bmVideoStandards		= 0;

	od = &opts->uvc_output_terminal;
	od->bLength			= UVC_DT_OUTPUT_TERMINAL_SIZE;

diff --git a/drivers/usb/gadget/legacy/webcam.c b/drivers/usb/gadget/legacy/webcam.c
index 3a61de4bb2b1..accb4dacf715 100644
--- a/drivers/usb/gadget/legacy/webcam.c
+++ b/drivers/usb/gadget/legacy/webcam.c

@@ -125,6 +125,7 @@ static const struct uvc_processing_unit_descriptor uvc_processing = {

	.bmControls[0]		= 1,
	.bmControls[1]		= 0,
	.iProcessing		= 0,
+	.bmVideoStandrads	= 0,
};

static const struct uvc_output_terminal_descriptor uvc_output_terminal = {

diff --git a/include/uapi/linux/usb/video.h b/include/uapi/linux/usb/video.h
index d854cb19c42c..bfdae12cdacf 100644
--- a/include/uapi/linux/usb/video.h
+++ b/include/uapi/linux/usb/video.h

@@ -302,9 +302,10 @@ struct uvc_processing_unit_descriptor {

	__u8   bControlSize;
	__u8   bmControls[2];
	__u8   iProcessing;
+	__u8   bmVideoStandards;
} __attribute__((__packed__));

-#define UVC_DT_PROCESSING_UNIT_SIZE(n)			(9+(n))
+#define UVC_DT_PROCESSING_UNIT_SIZE(n)			(10+(n))

/* 3.7.2.6. Extension Unit Descriptor */
struct uvc_extension_unit_descriptor {
--
2.25.1