From a03bede5c73a6876fa891cfe82a65460dc9f4698 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Mon, 1 Oct 2012 10:31:53 -0400 Subject: USB: update documentation for URB_ISO_ASAP This patch (as1611) updates the USB documentation and kerneldoc to give a more precise meaning for the URB_ISO_ASAP flag and to explain more of the details of scheduling for isochronous URBs. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- include/linux/usb.h | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-) (limited to 'include/linux/usb.h') diff --git a/include/linux/usb.h b/include/linux/usb.h index 10278d18709c..f92cdf0c1457 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -1129,8 +1129,8 @@ extern int usb_disabled(void); * Note: URB_DIR_IN/OUT is automatically set in usb_submit_urb(). */ #define URB_SHORT_NOT_OK 0x0001 /* report short reads as errors */ -#define URB_ISO_ASAP 0x0002 /* iso-only, urb->start_frame - * ignored */ +#define URB_ISO_ASAP 0x0002 /* iso-only; use the first unexpired + * slot in the schedule */ #define URB_NO_TRANSFER_DMA_MAP 0x0004 /* urb->transfer_dma valid on submit */ #define URB_NO_FSBR 0x0020 /* UHCI-specific */ #define URB_ZERO_PACKET 0x0040 /* Finish bulk OUT with short packet */ @@ -1309,15 +1309,20 @@ typedef void (*usb_complete_t)(struct urb *); * the transfer interval in the endpoint descriptor is logarithmic. * Device drivers must convert that value to linear units themselves.) * - * Isochronous URBs normally use the URB_ISO_ASAP transfer flag, telling - * the host controller to schedule the transfer as soon as bandwidth - * utilization allows, and then set start_frame to reflect the actual frame - * selected during submission. Otherwise drivers must specify the start_frame - * and handle the case where the transfer can't begin then. However, drivers - * won't know how bandwidth is currently allocated, and while they can - * find the current frame using usb_get_current_frame_number () they can't - * know the range for that frame number. (Ranges for frame counter values - * are HC-specific, and can go from 256 to 65536 frames from "now".) + * If an isochronous endpoint queue isn't already running, the host + * controller will schedule a new URB to start as soon as bandwidth + * utilization allows. If the queue is running then a new URB will be + * scheduled to start in the first transfer slot following the end of the + * preceding URB, if that slot has not already expired. If the slot has + * expired (which can happen when IRQ delivery is delayed for a long time), + * the scheduling behavior depends on the URB_ISO_ASAP flag. If the flag + * is clear then the URB will be scheduled to start in the expired slot, + * implying that some of its packets will not be transferred; if the flag + * is set then the URB will be scheduled in the first unexpired slot, + * breaking the queue's synchronization. Upon URB completion, the + * start_frame field will be set to the (micro)frame number in which the + * transfer was scheduled. Ranges for frame counter values are HC-specific + * and can go from as low as 256 to as high as 65536 frames. * * Isochronous URBs have a different data transfer model, in part because * the quality of service is only "best effort". Callers provide specially -- cgit v1.2.3 From 969ddcfc95c9a1849114fb72466d2fdea70f1d48 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Fri, 19 Oct 2012 11:03:02 -0400 Subject: USB: hub_for_each_child should skip unconnected ports This patch (as1619) improves the interface to the "hub_for_each_child" macro. The name clearly suggests that the macro iterates over child devices; it does not suggest that the loop will also iterate over unnconnected ports. The patch changes the macro so that it will skip over unconnected ports and iterate only the actual child devices. The two existing call sites are updated to avoid testing for a NULL child pointer, which is now unnecessary. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/devices.c | 18 ++++++++---------- drivers/usb/host/r8a66597-hcd.c | 6 ++---- include/linux/usb.h | 5 +++-- 3 files changed, 13 insertions(+), 16 deletions(-) (limited to 'include/linux/usb.h') diff --git a/drivers/usb/core/devices.c b/drivers/usb/core/devices.c index f460de31acee..cbacea933b18 100644 --- a/drivers/usb/core/devices.c +++ b/drivers/usb/core/devices.c @@ -591,16 +591,14 @@ static ssize_t usb_device_dump(char __user **buffer, size_t *nbytes, /* Now look at all of this device's children. */ usb_hub_for_each_child(usbdev, chix, childdev) { - if (childdev) { - usb_lock_device(childdev); - ret = usb_device_dump(buffer, nbytes, skip_bytes, - file_offset, childdev, bus, - level + 1, chix - 1, ++cnt); - usb_unlock_device(childdev); - if (ret == -EFAULT) - return total_written; - total_written += ret; - } + usb_lock_device(childdev); + ret = usb_device_dump(buffer, nbytes, skip_bytes, + file_offset, childdev, bus, + level + 1, chix - 1, ++cnt); + usb_unlock_device(childdev); + if (ret == -EFAULT) + return total_written; + total_written += ret; } return total_written; } diff --git a/drivers/usb/host/r8a66597-hcd.c b/drivers/usb/host/r8a66597-hcd.c index fcc09e5ec0ad..b3eea0ba97a9 100644 --- a/drivers/usb/host/r8a66597-hcd.c +++ b/drivers/usb/host/r8a66597-hcd.c @@ -2036,10 +2036,8 @@ static void collect_usb_address_map(struct usb_device *udev, unsigned long *map) udev->parent->descriptor.bDeviceClass == USB_CLASS_HUB) map[udev->devnum/32] |= (1 << (udev->devnum % 32)); - usb_hub_for_each_child(udev, chix, childdev) { - if (childdev) - collect_usb_address_map(childdev, map); - } + usb_hub_for_each_child(udev, chix, childdev) + collect_usb_address_map(childdev, map); } /* this function must be called with interrupt disabled */ diff --git a/include/linux/usb.h b/include/linux/usb.h index f92cdf0c1457..5df7c87b277f 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -588,8 +588,9 @@ extern struct usb_device *usb_hub_find_child(struct usb_device *hdev, */ #define usb_hub_for_each_child(hdev, port1, child) \ for (port1 = 1, child = usb_hub_find_child(hdev, port1); \ - port1 <= hdev->maxchild; \ - child = usb_hub_find_child(hdev, ++port1)) + port1 <= hdev->maxchild; \ + child = usb_hub_find_child(hdev, ++port1)) \ + if (!child) continue; else /* USB device locking */ #define usb_lock_device(udev) device_lock(&(udev)->dev) -- cgit v1.2.3 From bfd1e910139be73fb0783a0b3171fc79e6afa031 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Fri, 19 Oct 2012 11:03:39 -0400 Subject: USB: speed up usb_bus_resume() This patch (as1620) speeds up USB root-hub resumes in the common case where every enabled port has its suspend feature set (which currently will be true for every runtime resume of the root hub). If all the enabled ports are suspended then resuming the root hub won't resume any of the downstream devices. In this case there's no need for a Resume Recovery delay, because that delay is meant to give devices a chance to get ready for active use. To keep track of the port suspend features, the patch adds a "port_is_suspended" flag to struct usb_device. This has to be tracked separately from the device's state; it's entirely possible for a USB-2 device to be suspended while the suspend feature on its parent port is clear. The reason is that devices will go into suspend whenever their parent hub does. Signed-off-by: Alan Stern Reviewed-by: Peter Chen Tested-by: Peter Chen Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hcd.c | 19 +++++++++++++++++-- drivers/usb/core/hub.c | 2 ++ include/linux/usb.h | 2 ++ 3 files changed, 21 insertions(+), 2 deletions(-) (limited to 'include/linux/usb.h') diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index 1e741bca0265..eaa14514e173 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -2039,8 +2039,9 @@ int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg) status = hcd->driver->bus_resume(hcd); clear_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags); if (status == 0) { - /* TRSMRCY = 10 msec */ - msleep(10); + struct usb_device *udev; + int port1; + spin_lock_irq(&hcd_root_hub_lock); if (!HCD_DEAD(hcd)) { usb_set_device_state(rhdev, rhdev->actconfig @@ -2050,6 +2051,20 @@ int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg) hcd->state = HC_STATE_RUNNING; } spin_unlock_irq(&hcd_root_hub_lock); + + /* + * Check whether any of the enabled ports on the root hub are + * unsuspended. If they are then a TRSMRCY delay is needed + * (this is what the USB-2 spec calls a "global resume"). + * Otherwise we can skip the delay. + */ + usb_hub_for_each_child(rhdev, port1, udev) { + if (udev->state != USB_STATE_NOTATTACHED && + !udev->port_is_suspended) { + usleep_range(10000, 11000); /* TRSMRCY */ + break; + } + } } else { hcd->state = old_state; dev_dbg(&rhdev->dev, "bus %s fail, err %d\n", diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 64854d76f529..e729e94cb751 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -2876,6 +2876,7 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg) (PMSG_IS_AUTO(msg) ? "auto-" : ""), udev->do_remote_wakeup); usb_set_device_state(udev, USB_STATE_SUSPENDED); + udev->port_is_suspended = 1; msleep(10); } usb_mark_last_busy(hub->hdev); @@ -3040,6 +3041,7 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg) SuspendCleared: if (status == 0) { + udev->port_is_suspended = 0; if (hub_is_superspeed(hub->hdev)) { if (portchange & USB_PORT_STAT_C_LINK_STATE) clear_port_feature(hub->hdev, port1, diff --git a/include/linux/usb.h b/include/linux/usb.h index 5df7c87b277f..f51f9981de1e 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -482,6 +482,7 @@ struct usb3_lpm_parameters { * @connect_time: time device was first connected * @do_remote_wakeup: remote wakeup should be enabled * @reset_resume: needs reset instead of resume + * @port_is_suspended: the upstream port is suspended (L2 or U3) * @wusb_dev: if this is a Wireless USB device, link to the WUSB * specific data for the device. * @slot_id: Slot ID assigned by xHCI @@ -560,6 +561,7 @@ struct usb_device { unsigned do_remote_wakeup:1; unsigned reset_resume:1; + unsigned port_is_suspended:1; #endif struct wusb_dev *wusb_dev; int slot_id; -- cgit v1.2.3 From 17b72feb2be14e6d37023267dc0e199e8e0e3fdc Mon Sep 17 00:00:00 2001 From: Bjørn Mork Date: Wed, 31 Oct 2012 06:08:39 +0100 Subject: USB: add USB_DEVICE_INTERFACE_CLASS macro MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Matching on device and interface class with with unspecified subclass and protocol is sometimes useful. This is slightly different from USB_DEVICE_AND_INTERFACE_INFO which requires the full interface class/subclass/protocol triplet. Signed-off-by: Bjørn Mork Signed-off-by: Greg Kroah-Hartman --- include/linux/usb.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'include/linux/usb.h') diff --git a/include/linux/usb.h b/include/linux/usb.h index f51f9981de1e..689b14b26c8d 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -807,6 +807,22 @@ static inline int usb_make_path(struct usb_device *dev, char *buf, size_t size) .bcdDevice_lo = (lo), \ .bcdDevice_hi = (hi) +/** + * USB_DEVICE_INTERFACE_CLASS - describe a usb device with a specific interface class + * @vend: the 16 bit USB Vendor ID + * @prod: the 16 bit USB Product ID + * @cl: bInterfaceClass value + * + * This macro is used to create a struct usb_device_id that matches a + * specific interface class of devices. + */ +#define USB_DEVICE_INTERFACE_CLASS(vend, prod, cl) \ + .match_flags = USB_DEVICE_ID_MATCH_DEVICE | \ + USB_DEVICE_ID_MATCH_INT_CLASS, \ + .idVendor = (vend), \ + .idProduct = (prod), \ + .bInterfaceClass = (cl) + /** * USB_DEVICE_INTERFACE_PROTOCOL - describe a usb device with a specific interface protocol * @vend: the 16 bit USB Vendor ID -- cgit v1.2.3