diff options
Diffstat (limited to 'drivers/usb/core')
| -rw-r--r-- | drivers/usb/core/hcd.c | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index 6a05e693445..3aaee2811f0 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -1814,6 +1814,75 @@ void usb_hcd_reset_endpoint(struct usb_device *udev, } } +/** + * usb_alloc_streams - allocate bulk endpoint stream IDs. + * @interface: alternate setting that includes all endpoints. + * @eps: array of endpoints that need streams. + * @num_eps: number of endpoints in the array. + * @num_streams: number of streams to allocate. + * @mem_flags: flags hcd should use to allocate memory. + * + * Sets up a group of bulk endpoints to have num_streams stream IDs available. + * Drivers may queue multiple transfers to different stream IDs, which may + * complete in a different order than they were queued. + */ +int usb_alloc_streams(struct usb_interface *interface, + struct usb_host_endpoint **eps, unsigned int num_eps, + unsigned int num_streams, gfp_t mem_flags) +{ + struct usb_hcd *hcd; + struct usb_device *dev; + int i; + + dev = interface_to_usbdev(interface); + hcd = bus_to_hcd(dev->bus); + if (!hcd->driver->alloc_streams || !hcd->driver->free_streams) + return -EINVAL; + if (dev->speed != USB_SPEED_SUPER) + return -EINVAL; + + /* Streams only apply to bulk endpoints. */ + for (i = 0; i < num_eps; i++) + if (!usb_endpoint_xfer_bulk(&eps[i]->desc)) + return -EINVAL; + + return hcd->driver->alloc_streams(hcd, dev, eps, num_eps, + num_streams, mem_flags); +} +EXPORT_SYMBOL_GPL(usb_alloc_streams); + +/** + * usb_free_streams - free bulk endpoint stream IDs. + * @interface: alternate setting that includes all endpoints. + * @eps: array of endpoints to remove streams from. + * @num_eps: number of endpoints in the array. + * @mem_flags: flags hcd should use to allocate memory. + * + * Reverts a group of bulk endpoints back to not using stream IDs. + * Can fail if we are given bad arguments, or HCD is broken. + */ +void usb_free_streams(struct usb_interface *interface, + struct usb_host_endpoint **eps, unsigned int num_eps, + gfp_t mem_flags) +{ + struct usb_hcd *hcd; + struct usb_device *dev; + int i; + + dev = interface_to_usbdev(interface); + hcd = bus_to_hcd(dev->bus); + if (dev->speed != USB_SPEED_SUPER) + return; + + /* Streams only apply to bulk endpoints. */ + for (i = 0; i < num_eps; i++) + if (!usb_endpoint_xfer_bulk(&eps[i]->desc)) + return; + + hcd->driver->free_streams(hcd, dev, eps, num_eps, mem_flags); +} +EXPORT_SYMBOL_GPL(usb_free_streams); + /* Protect against drivers that try to unlink URBs after the device * is gone, by waiting until all unlinks for @udev are finished. * Since we don't currently track URBs by device, simply wait until |