From: Alan Stern Date: Wed, 8 Aug 2007 15:59:18 +0000 (-0400) Subject: USB: don't touch sysfs stuff when altsetting is unchanged X-Git-Tag: v2.6.24-rc1~1395^2~101 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=d74d4a69dc1cc7ddc0eabb9c9f1e45005e2984eb;p=linux-2.6-omap-h63xx.git USB: don't touch sysfs stuff when altsetting is unchanged This patch (as955) prevents the interface-related sysfs files and endpoint pseudo-devices from being deleted and recreated when a call to usb_set_interface() specifies the current altsetting. Since the altsetting doesn't get changed, there's no need to do anything. Furthermore, avoiding changes to the endpoint devices will be necessary in the future. This code is called from usb_reset_device(), which gets invoked for reset-resume processing, but upcoming changes to the PM and driver cores will make it impossible to register devices while a suspend/resume transition is in progress. Since we don't need to re-register those endpoint devices anyhow, it's best to skip the whole thing. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index c905b35d4f8..d638375e22e 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -1173,6 +1173,7 @@ int usb_set_interface(struct usb_device *dev, int interface, int alternate) struct usb_host_interface *alt; int ret; int manual = 0; + int changed; if (dev->state == USB_STATE_SUSPENDED) return -EHOSTUNREACH; @@ -1212,7 +1213,8 @@ int usb_set_interface(struct usb_device *dev, int interface, int alternate) */ /* prevent submissions using previous endpoint settings */ - if (device_is_registered(&iface->dev)) + changed = (iface->cur_altsetting != alt); + if (changed && device_is_registered(&iface->dev)) usb_remove_sysfs_intf_files(iface); usb_disable_interface(dev, iface); @@ -1249,7 +1251,7 @@ int usb_set_interface(struct usb_device *dev, int interface, int alternate) * (Likewise, EP0 never "halts" on well designed devices.) */ usb_enable_interface(dev, iface); - if (device_is_registered(&iface->dev)) + if (changed && device_is_registered(&iface->dev)) usb_create_sysfs_intf_files(iface); return 0;