diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/core/hcd.c | 86 | ||||
| -rw-r--r-- | drivers/usb/core/hcd.h | 32 | ||||
| -rw-r--r-- | drivers/usb/core/message.c | 20 | ||||
| -rw-r--r-- | drivers/usb/core/urb.c | 6 |
4 files changed, 144 insertions, 0 deletions
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index 823744d80cb..b2da4753b12 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -1560,6 +1560,92 @@ rescan: } } +/* Check whether a new configuration or alt setting for an interface + * will exceed the bandwidth for the bus (or the host controller resources). + * Only pass in a non-NULL config or interface, not both! + * Passing NULL for both new_config and new_intf means the device will be + * de-configured by issuing a set configuration 0 command. + */ +int usb_hcd_check_bandwidth(struct usb_device *udev, + struct usb_host_config *new_config, + struct usb_interface *new_intf) +{ + int num_intfs, i, j; + struct usb_interface_cache *intf_cache; + struct usb_host_interface *alt = 0; + int ret = 0; + struct usb_hcd *hcd; + struct usb_host_endpoint *ep; + + hcd = bus_to_hcd(udev->bus); + if (!hcd->driver->check_bandwidth) + return 0; + + /* Configuration is being removed - set configuration 0 */ + if (!new_config && !new_intf) { + for (i = 1; i < 16; ++i) { + ep = udev->ep_out[i]; + if (ep) + hcd->driver->drop_endpoint(hcd, udev, ep); + ep = udev->ep_in[i]; + if (ep) + hcd->driver->drop_endpoint(hcd, udev, ep); + } + hcd->driver->check_bandwidth(hcd, udev); + return 0; + } + /* Check if the HCD says there's enough bandwidth. Enable all endpoints + * each interface's alt setting 0 and ask the HCD to check the bandwidth + * of the bus. There will always be bandwidth for endpoint 0, so it's + * ok to exclude it. + */ + if (new_config) { + num_intfs = new_config->desc.bNumInterfaces; + /* Remove endpoints (except endpoint 0, which is always on the + * schedule) from the old config from the schedule + */ + for (i = 1; i < 16; ++i) { + ep = udev->ep_out[i]; + if (ep) { + ret = hcd->driver->drop_endpoint(hcd, udev, ep); + if (ret < 0) + goto reset; + } + ep = udev->ep_in[i]; + if (ep) { + ret = hcd->driver->drop_endpoint(hcd, udev, ep); + if (ret < 0) + goto reset; + } + } + for (i = 0; i < num_intfs; ++i) { + + /* Dig the endpoints for alt setting 0 out of the + * interface cache for this interface + */ + intf_cache = new_config->intf_cache[i]; + for (j = 0; j < intf_cache->num_altsetting; j++) { + if (intf_cache->altsetting[j].desc.bAlternateSetting == 0) + alt = &intf_cache->altsetting[j]; + } + if (!alt) { + printk(KERN_DEBUG "Did not find alt setting 0 for intf %d\n", i); + continue; + } + for (j = 0; j < alt->desc.bNumEndpoints; j++) { + ret = hcd->driver->add_endpoint(hcd, udev, &alt->endpoint[j]); + if (ret < 0) + goto reset; + } + } + } + ret = hcd->driver->check_bandwidth(hcd, udev); +reset: + if (ret < 0) + hcd->driver->reset_bandwidth(hcd, udev); + return ret; +} + /* 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/hcd.h b/drivers/usb/core/hcd.h index ae6d9db41ca..d397ecfd5b1 100644 --- a/drivers/usb/core/hcd.h +++ b/drivers/usb/core/hcd.h @@ -232,6 +232,35 @@ struct hc_driver { int (*alloc_dev)(struct usb_hcd *, struct usb_device *); /* Called by usb_release_dev to free HC device structures */ void (*free_dev)(struct usb_hcd *, struct usb_device *); + + /* Bandwidth computation functions */ + /* Note that add_endpoint() can only be called once per endpoint before + * check_bandwidth() or reset_bandwidth() must be called. + * drop_endpoint() can only be called once per endpoint also. + * A call to xhci_drop_endpoint() followed by a call to xhci_add_endpoint() will + * add the endpoint to the schedule with possibly new parameters denoted by a + * different endpoint descriptor in usb_host_endpoint. + * A call to xhci_add_endpoint() followed by a call to xhci_drop_endpoint() is + * not allowed. + */ + /* Allocate endpoint resources and add them to a new schedule */ + int (*add_endpoint)(struct usb_hcd *, struct usb_device *, struct usb_host_endpoint *); + /* Drop an endpoint from a new schedule */ + int (*drop_endpoint)(struct usb_hcd *, struct usb_device *, struct usb_host_endpoint *); + /* Check that a new hardware configuration, set using + * endpoint_enable and endpoint_disable, does not exceed bus + * bandwidth. This must be called before any set configuration + * or set interface requests are sent to the device. + */ + int (*check_bandwidth)(struct usb_hcd *, struct usb_device *); + /* Reset the device schedule to the last known good schedule, + * which was set from a previous successful call to + * check_bandwidth(). This reverts any add_endpoint() and + * drop_endpoint() calls since that last successful call. + * Used for when a check_bandwidth() call fails due to resource + * or bandwidth constraints. + */ + void (*reset_bandwidth)(struct usb_hcd *, struct usb_device *); /* Returns the hardware-chosen device address */ int (*address_device)(struct usb_hcd *, struct usb_device *udev); }; @@ -252,6 +281,9 @@ extern void usb_hcd_disable_endpoint(struct usb_device *udev, extern void usb_hcd_reset_endpoint(struct usb_device *udev, struct usb_host_endpoint *ep); extern void usb_hcd_synchronize_unlinks(struct usb_device *udev); +extern int usb_hcd_check_bandwidth(struct usb_device *udev, + struct usb_host_config *new_config, + struct usb_interface *new_intf); extern int usb_hcd_get_frame_number(struct usb_device *udev); extern struct usb_hcd *usb_create_hcd(const struct hc_driver *driver, diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index 9bd26dec759..3a2e69ec2f2 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -510,6 +510,10 @@ EXPORT_SYMBOL_GPL(usb_sg_init); * could be transferred. That capability is less useful for low or full * speed interrupt endpoints, which allow at most one packet per millisecond, * of at most 8 or 64 bytes (respectively). + * + * It is not necessary to call this function to reserve bandwidth for devices + * under an xHCI host controller, as the bandwidth is reserved when the + * configuration or interface alt setting is selected. */ void usb_sg_wait(struct usb_sg_request *io) { @@ -1653,6 +1657,21 @@ free_interfaces: if (ret) goto free_interfaces; + /* Make sure we have bandwidth (and available HCD resources) for this + * configuration. Remove endpoints from the schedule if we're dropping + * this configuration to set configuration 0. After this point, the + * host controller will not allow submissions to dropped endpoints. If + * this call fails, the device state is unchanged. + */ + if (cp) + ret = usb_hcd_check_bandwidth(dev, cp, NULL); + else + ret = usb_hcd_check_bandwidth(dev, NULL, NULL); + if (ret < 0) { + usb_autosuspend_device(dev); + goto free_interfaces; + } + /* if it's already configured, clear out old state first. * getting rid of old interfaces means unbinding their drivers. */ @@ -1675,6 +1694,7 @@ free_interfaces: dev->actconfig = cp; if (!cp) { usb_set_device_state(dev, USB_STATE_ADDRESS); + usb_hcd_check_bandwidth(dev, NULL, NULL); usb_autosuspend_device(dev); goto free_interfaces; } diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c index 02eb0ef7a4c..0885d4abdc6 100644 --- a/drivers/usb/core/urb.c +++ b/drivers/usb/core/urb.c @@ -241,6 +241,12 @@ EXPORT_SYMBOL_GPL(usb_unanchor_urb); * If the USB subsystem can't allocate sufficient bandwidth to perform * the periodic request, submitting such a periodic request should fail. * + * For devices under xHCI, the bandwidth is reserved at configuration time, or + * when the alt setting is selected. If there is not enough bus bandwidth, the + * configuration/alt setting request will fail. Therefore, submissions to + * periodic endpoints on devices under xHCI should never fail due to bandwidth + * constraints. + * * Device drivers must explicitly request that repetition, by ensuring that * some URB is always on the endpoint's queue (except possibly for short * periods during completion callacks). When there is no longer an urb |