On 20.8.2025 17.38, Sakari Ailus wrote:
Introduce usb_endpoint_is_hs_isoc_double() tell whether an endpoint
conforms to USB 2.0 Isochronous Double IN Bandwidth ECN.
Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
---
drivers/usb/core/usb.c | 19 +++++++++++++++++++
include/linux/usb.h | 3 +++
2 files changed, 22 insertions(+)
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index ca9ff6ad8e73..939dc4aafb89 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -1139,6 +1139,25 @@ u32 usb_endpoint_max_periodic_payload(struct usb_device *udev,
}
EXPORT_SYMBOL_GPL(usb_endpoint_max_periodic_payload);
+/**
+ * usb_endpoint_is_hs_isoc_double - Tell whether an endpoint uses USB 2
+ * Isochronous Double IN Bandwidth
+ * @udev: The USB device
+ * @ep: The endpoint
+ *
+ * Returns: true if an endpoint @ep conforms to USB 2 Isochronous Double IN
+ * Bandwidth ECN, false otherwise.
+ */
+bool usb_endpoint_is_hs_isoc_double(struct usb_device *udev,
+ const struct usb_host_endpoint *ep)
+{
+ return ep->eusb2_isoc_ep_comp.bDescriptorType &&
+ le16_to_cpu(udev->descriptor.bcdUSB) == 0x220 &&
+ usb_endpoint_is_isoc_in(&ep->desc) &&
+ !le16_to_cpu(ep->desc.wMaxPacketSize);
+}
+EXPORT_SYMBOL_GPL(usb_endpoint_is_hs_isoc_double);
+
/*
* Notifications of device and interface registration
*/
diff --git a/include/linux/usb.h b/include/linux/usb.h
index e9cf2786d8bd..70ef00c42d22 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -2042,6 +2042,9 @@ static inline u16 usb_maxpacket(struct usb_device *udev, int pipe)
u32 usb_endpoint_max_periodic_payload(struct usb_device *udev,
const struct usb_host_endpoint *ep);
+bool usb_endpoint_is_hs_isoc_double(struct usb_device *udev,
+ const struct usb_host_endpoint *ep);
+
/* translate USB error codes to codes user space understands */
static inline int usb_translate_errors(int error_code)
{
Acked-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
