diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 916bcd539afa..09bd3c3ad8b1 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -38,6 +38,9 @@ #define USB_VENDOR_GENESYS_LOGIC 0x05e3 #define HUB_QUIRK_CHECK_PORT_AUTOSUSPEND 0x01 +#define USB_TP_TRANSMISSION_DELAY 40 /* ns */ +#define USB_TP_TRANSMISSION_DELAY_MAX 65535 /* ns */ + /* Protect struct usb_device->state and ->children members * Note: Both are also protected by ->dev.sem, except that ->state can * change to USB_STATE_NOTATTACHED even when the semaphore isn't held. */ @@ -1350,6 +1353,20 @@ static int hub_configure(struct usb_hub *hub, goto fail; } + /* + * Accumulate wHubDelay + 40ns for every hub in the tree of devices. + * The resulting value will be used for SetIsochDelay() request. + */ + if (hub_is_superspeed(hdev) || hub_is_superspeedplus(hdev)) { + u32 delay = __le16_to_cpu(hub->descriptor->u.ss.wHubDelay); + + if (hdev->parent) + delay += hdev->parent->hub_delay; + + delay += USB_TP_TRANSMISSION_DELAY; + hdev->hub_delay = min_t(u32, delay, USB_TP_TRANSMISSION_DELAY_MAX); + } + maxchild = hub->descriptor->bNbrPorts; dev_info(hub_dev, "%d port%s detected\n", maxchild, (maxchild == 1) ? "" : "s"); @@ -4597,7 +4614,20 @@ hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1, if (retval >= 0) retval = -EMSGSIZE; } else { + u32 delay; + retval = 0; + + delay = udev->parent->hub_delay; + udev->hub_delay = min_t(u32, delay, + USB_TP_TRANSMISSION_DELAY_MAX); + retval = usb_set_isoch_delay(udev); + if (retval) { + dev_dbg(&udev->dev, + "Failed set isoch delay, error %d\n", + retval); + retval = 0; + } break; } } diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index dac4adeec213..c64cf6c4a83d 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -916,6 +916,30 @@ int usb_get_device_descriptor(struct usb_device *dev, unsigned int size) return ret; } +/* + * usb_set_isoch_delay - informs the device of the packet transmit delay + * @dev: the device whose delay is to be informed + * Context: !in_interrupt() + * + * Since this is an optional request, we don't bother if it fails. + */ +int usb_set_isoch_delay(struct usb_device *dev) +{ + /* skip hub devices */ + if (dev->descriptor.bDeviceClass == USB_CLASS_HUB) + return 0; + + /* skip non-SS/non-SSP devices */ + if (dev->speed < USB_SPEED_SUPER) + return 0; + + return usb_control_msg(dev, usb_sndctrlpipe(dev, 0), + USB_REQ_SET_ISOCH_DELAY, + USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE, + cpu_to_le16(dev->hub_delay), 0, NULL, 0, + USB_CTRL_SET_TIMEOUT); +} + /** * usb_get_status - issues a GET_STATUS call * @dev: the device whose status is being checked diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h index 2bee08d084ae..149cc7480971 100644 --- a/drivers/usb/core/usb.h +++ b/drivers/usb/core/usb.h @@ -40,6 +40,7 @@ extern int usb_remove_device(struct usb_device *udev); extern int usb_get_device_descriptor(struct usb_device *dev, unsigned int size); +extern int usb_set_isoch_delay(struct usb_device *dev); extern int usb_get_bos_descriptor(struct usb_device *dev); extern void usb_release_bos_descriptor(struct usb_device *dev); extern char *usb_cache_string(struct usb_device *udev, int index); diff --git a/include/linux/usb.h b/include/linux/usb.h index fe665a0d5bce..0173597e59aa 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -609,6 +609,10 @@ struct usb3_lpm_parameters { * to keep track of the number of functions that require USB 3.0 Link Power * Management to be disabled for this usb_device. This count should only * be manipulated by those functions, with the bandwidth_mutex is held. + * @hub_delay: cached value consisting of: + * parent->hub_delay + wHubDelay + tTPTransmissionDelay (40ns) + * + * Will be used as wValue for SetIsochDelay requests. * * Notes: * Usbcore drivers should not set usbdev->state directly. Instead use @@ -689,6 +693,8 @@ struct usb_device { struct usb3_lpm_parameters u1_params; struct usb3_lpm_parameters u2_params; unsigned lpm_disable_count; + + u16 hub_delay; }; #define to_usb_device(d) container_of(d, struct usb_device, dev)