2021-03-15 07:21:47

by Pawel Laszczak

[permalink] [raw]
Subject: [PATCH v4 2/2] usb: webcam: Invalid size of Processing Unit Descriptor

From: Pawel Laszczak <[email protected]>

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 <[email protected]>
Signed-off-by: Pawel Laszczak <[email protected]>

---
Changelog:
v4:
- fixed compilation error caused by v2
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,
+ .bmVideoStandards = 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


2021-03-16 11:16:21

by Peter Chen

[permalink] [raw]
Subject: Re: [PATCH v4 2/2] usb: webcam: Invalid size of Processing Unit Descriptor

On 21-03-15 08:17:48, Pawel Laszczak wrote:
> From: Pawel Laszczak <[email protected]>
>
> 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 <[email protected]>
> Signed-off-by: Pawel Laszczak <[email protected]>
>

Reviewed-by: Peter Chen <[email protected]>

> ---
> Changelog:
> v4:
> - fixed compilation error caused by v2
> 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,
> + .bmVideoStandards = 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
>

--

Thanks,
Peter Chen