From 25d35f666c0f21d3e138beff60945dc277e14fae 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 If polling intervals are shortened, any bandwidth reservations are no longer valid but in practice polling intervals are only ever relaxed.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 d0f4560..4d6cff9 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -1941,6 +1941,16 @@ reset: 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 266c69d..5c52dd5 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -1120,6 +1120,21 @@ 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 e656e7b..3ac4b26 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -1816,6 +1816,8 @@ 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 712b2a6..879b59e 100644 --- a/include/linux/usb/hcd.h +++ b/include/linux/usb/hcd.h @@ -382,6 +382,11 @@ 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); /* Returns the hardware-chosen device address */ int (*address_device)(struct usb_hcd *, struct usb_device *udev); /* prepares the hardware to send commands to the device */ @@ -443,6 +448,8 @@ 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, -- 2.7.4