From 7c517e79b6ef29b331221829a125d816b87e8d02 Mon Sep 17 00:00:00 2001 From: Jonathan Bell Date: Tue, 11 Jun 2019 10:55:00 +0100 Subject: [PATCH] usb: add plumbing for updating interrupt endpoint interval state xHCI caches device and endpoint data after the interface is configured, so an explicit command needs to be issued for any device driver wanting to alter the polling interval of an endpoint. Add usb_fixup_endpoint() to allow drivers to do this. The fixup must be called after calculating endpoint bandwidth requirements but before any URBs are submitted. If polling intervals are shortened, any bandwidth reservations are no longer valid but in practice polling intervals are only ever relaxed. Limit the scope to interrupt transfers for now. Signed-off-by: Jonathan Bell --- drivers/usb/core/hcd.c | 10 ++++++++++ drivers/usb/core/message.c | 15 +++++++++++++++ include/linux/usb.h | 2 ++ include/linux/usb/hcd.h | 7 +++++++ 4 files changed, 34 insertions(+) diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index 12b6dfeaf658c..0de6ac7681888 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -1952,6 +1952,16 @@ int usb_hcd_alloc_bandwidth(struct usb_device *udev, return ret; } +void usb_hcd_fixup_endpoint(struct usb_device *udev, + struct usb_host_endpoint *ep, int interval) +{ + struct usb_hcd *hcd; + + hcd = bus_to_hcd(udev->bus); + if (hcd->driver->fixup_endpoint) + hcd->driver->fixup_endpoint(hcd, udev, ep, interval); +} + /* Disables the endpoint: synchronizes with the hcd to make sure all * endpoint state is gone from hardware. usb_hcd_flush_endpoint() must * have been called previously. Use for set_configuration, set_interface, diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index 1ee070e98fc82..89c7339386a64 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -1265,6 +1265,21 @@ static void remove_intf_ep_devs(struct usb_interface *intf) intf->ep_devs_created = 0; } +void usb_fixup_endpoint(struct usb_device *dev, int epaddr, int interval) +{ + unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK; + struct usb_host_endpoint *ep; + + if (usb_endpoint_out(epaddr)) + ep = dev->ep_out[epnum]; + else + ep = dev->ep_in[epnum]; + + if (ep && usb_endpoint_xfer_int(&ep->desc)) + usb_hcd_fixup_endpoint(dev, ep, interval); +} +EXPORT_SYMBOL_GPL(usb_fixup_endpoint); + /** * usb_disable_endpoint -- Disable an endpoint by address * @dev: the device whose endpoint is being disabled diff --git a/include/linux/usb.h b/include/linux/usb.h index a21074861f91f..4a521591a357b 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -1888,6 +1888,8 @@ extern int usb_clear_halt(struct usb_device *dev, int pipe); extern int usb_reset_configuration(struct usb_device *dev); extern int usb_set_interface(struct usb_device *dev, int ifnum, int alternate); extern void usb_reset_endpoint(struct usb_device *dev, unsigned int epaddr); +extern void usb_fixup_endpoint(struct usb_device *dev, int epaddr, + int interval); /* this request isn't really synchronous, but it belongs with the others */ extern int usb_driver_set_configuration(struct usb_device *udev, int config); diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h index d0e19ac3ba6ce..e5d141653cd56 100644 --- a/include/linux/usb/hcd.h +++ b/include/linux/usb/hcd.h @@ -372,6 +372,11 @@ struct hc_driver { * or bandwidth constraints. */ void (*reset_bandwidth)(struct usb_hcd *, struct usb_device *); + /* Override the endpoint-derived interval + * (if there is any cached hardware state). + */ + void (*fixup_endpoint)(struct usb_hcd *hcd, struct usb_device *udev, + struct usb_host_endpoint *ep, int interval); /* Set the hardware-chosen device address */ int (*address_device)(struct usb_hcd *, struct usb_device *udev, unsigned int timeout_ms); @@ -437,6 +442,8 @@ extern void usb_hcd_unmap_urb_setup_for_dma(struct usb_hcd *, struct urb *); extern void usb_hcd_unmap_urb_for_dma(struct usb_hcd *, struct urb *); extern void usb_hcd_flush_endpoint(struct usb_device *udev, struct usb_host_endpoint *ep); +extern void usb_hcd_fixup_endpoint(struct usb_device *udev, + struct usb_host_endpoint *ep, int interval); extern void usb_hcd_disable_endpoint(struct usb_device *udev, struct usb_host_endpoint *ep); extern void usb_hcd_reset_endpoint(struct usb_device *udev,