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-rw-r--r--include/linux/usb.h32
1 files changed, 25 insertions, 7 deletions
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 0eec2689b95..001629cd1a9 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -337,6 +337,7 @@ struct usb_bus {
* the ep queue on a short transfer
* with the URB_SHORT_NOT_OK flag set.
*/
+ unsigned no_sg_constraint:1; /* no sg constraint */
unsigned sg_tablesize; /* 0 or largest number of sg list entries */
int devnum_next; /* Next open device number in
@@ -684,6 +685,11 @@ static inline bool usb_device_supports_ltm(struct usb_device *udev)
return udev->bos->ss_cap->bmAttributes & USB_LTM_SUPPORT;
}
+static inline bool usb_device_no_sg_constraint(struct usb_device *udev)
+{
+ return udev && udev->bus && udev->bus->no_sg_constraint;
+}
+
/*-------------------------------------------------------------------------*/
@@ -708,7 +714,10 @@ extern int usb_driver_claim_interface(struct usb_driver *driver,
* usb_interface_claimed - returns true iff an interface is claimed
* @iface: the interface being checked
*
- * Returns true (nonzero) iff the interface is claimed, else false (zero).
+ * Return: %true (nonzero) iff the interface is claimed, else %false
+ * (zero).
+ *
+ * Note:
* Callers must own the driver model's usb bus readlock. So driver
* probe() entries don't need extra locking, but other call contexts
* may need to explicitly claim that lock.
@@ -745,8 +754,9 @@ extern struct usb_host_interface *usb_find_alt_setting(
* @buf: where to put the string
* @size: how big is "buf"?
*
- * Returns length of the string (> 0) or negative if size was too small.
+ * Return: Length of the string (> 0) or negative if size was too small.
*
+ * Note:
* This identifier is intended to be "stable", reflecting physical paths in
* hardware such as physical bus addresses for host controllers or ports on
* USB hubs. That makes it stay the same until systems are physically
@@ -1247,7 +1257,9 @@ typedef void (*usb_complete_t)(struct urb *);
* the device driver is saying that it provided this DMA address,
* which the host controller driver should use in preference to the
* transfer_buffer.
- * @sg: scatter gather buffer list
+ * @sg: scatter gather buffer list, the buffer size of each element in
+ * the list (except the last) must be divisible by the endpoint's
+ * max packet size if no_sg_constraint isn't set in 'struct usb_bus'
* @num_mapped_sgs: (internal) number of mapped sg entries
* @num_sgs: number of entries in the sg list
* @transfer_buffer_length: How big is transfer_buffer. The transfer may
@@ -1534,10 +1546,16 @@ static inline void usb_fill_int_urb(struct urb *urb,
urb->transfer_buffer_length = buffer_length;
urb->complete = complete_fn;
urb->context = context;
- if (dev->speed == USB_SPEED_HIGH || dev->speed == USB_SPEED_SUPER)
+
+ if (dev->speed == USB_SPEED_HIGH || dev->speed == USB_SPEED_SUPER) {
+ /* make sure interval is within allowed range */
+ interval = clamp(interval, 1, 16);
+
urb->interval = 1 << (interval - 1);
- else
+ } else {
urb->interval = interval;
+ }
+
urb->start_frame = -1;
}
@@ -1570,7 +1588,7 @@ extern int usb_anchor_empty(struct usb_anchor *anchor);
* usb_urb_dir_in - check if an URB describes an IN transfer
* @urb: URB to be checked
*
- * Returns 1 if @urb describes an IN transfer (device-to-host),
+ * Return: 1 if @urb describes an IN transfer (device-to-host),
* otherwise 0.
*/
static inline int usb_urb_dir_in(struct urb *urb)
@@ -1582,7 +1600,7 @@ static inline int usb_urb_dir_in(struct urb *urb)
* usb_urb_dir_out - check if an URB describes an OUT transfer
* @urb: URB to be checked
*
- * Returns 1 if @urb describes an OUT transfer (host-to-device),
+ * Return: 1 if @urb describes an OUT transfer (host-to-device),
* otherwise 0.
*/
static inline int usb_urb_dir_out(struct urb *urb)