From 969ddcfc95c9a1849114fb72466d2fdea70f1d48 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Fri, 19 Oct 2012 11:03:02 -0400 Subject: [PATCH] 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(-) 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)