The completion of the usb status phase from uvc_function_set_alt needs
to be delayed until uvc_v4l2_streamon/off. This is currently done by
uvc_function_set_alt returning USB_GADGET_DELAYED_STATUS and
composite_setup detecting this to increment cdev->delayed_status.
However, if uvc_v4l2_streamon/off is called in between this return and
increment, uvc_function_setup_continue within uvc_v4l2_streamon/off will
WARN that cdev->delayed_status is zero.
To fix situations like this, add a function to increment
cdev->delayed_status.
Signed-off-by: Paul Elder <paul.elder@xxxxxxxx>
---
drivers/usb/gadget/composite.c | 6 ++++++
include/linux/usb/composite.h | 2 ++
2 files changed, 8 insertions(+)
diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 77c7ecca816a..c02ab640a7ae 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -1548,6 +1548,12 @@ static int fill_ext_prop(struct usb_configuration *c, int interface, u8 *buf)
return 0;
}
+void usb_composite_setup_delay(struct usb_composite_dev *cdev)
+{
+ cdev->delayed_status++;
+}
+EXPORT_SYMBOL(usb_composite_setup_delay);
+
/*
* The setup() callback implements all the ep0 functionality that's
* not handled lower down, in hardware or the hardware driver(like
diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h
index cef0e44601f8..049f77a4d42b 100644
--- a/include/linux/usb/composite.h
+++ b/include/linux/usb/composite.h
@@ -524,6 +524,8 @@ extern int composite_setup(struct usb_gadget *gadget,
extern void composite_suspend(struct usb_gadget *gadget);
extern void composite_resume(struct usb_gadget *gadget);
+extern void usb_composite_setup_delay(struct usb_composite_dev *c);
+
/*
* Some systems will need runtime overrides for the product identifiers
* published in the device descriptor, either numbers or strings or both.
--
2.17.0
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