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    USB: Fix duplicate sysfs problem after device reset. · 04a723ea
    Sarah Sharp 提交于
    Borislav Petkov reports issues with duplicate sysfs endpoint files after a
    resume from a hibernate.  It turns out that the code to support alternate
    settings under xHCI has issues when a device with a non-default alternate
    setting is reset during the hibernate:
    
    [  427.681810] Restarting tasks ...
    [  427.681995] hub 1-0:1.0: state 7 ports 6 chg 0004 evt 0000
    [  427.682019] usb usb3: usb resume
    [  427.682030] ohci_hcd 0000:00:12.0: wakeup root hub
    [  427.682191] hub 1-0:1.0: port 2, status 0501, change 0000, 480 Mb/s
    [  427.682205] usb 1-2: usb wakeup-resume
    [  427.682226] usb 1-2: finish reset-resume
    [  427.682886] done.
    [  427.734658] ehci_hcd 0000:00:12.2: port 2 high speed
    [  427.734663] ehci_hcd 0000:00:12.2: GetStatus port 2 status 001005 POWER sig=se0 PE CONNECT
    [  427.746682] hub 3-0:1.0: hub_reset_resume
    [  427.746693] hub 3-0:1.0: trying to enable port power on non-switchable hub
    [  427.786715] usb 1-2: reset high speed USB device using ehci_hcd and address 2
    [  427.839653] ehci_hcd 0000:00:12.2: port 2 high speed
    [  427.839666] ehci_hcd 0000:00:12.2: GetStatus port 2 status 001005 POWER sig=se0 PE CONNECT
    [  427.847717] ohci_hcd 0000:00:12.0: GetStatus roothub.portstatus [1] = 0x00010100 CSC PPS
    [  427.915497] hub 1-2:1.0: remove_intf_ep_devs: if: ffff88022f9e8800 ->ep_devs_created: 1
    [  427.915774] hub 1-2:1.0: remove_intf_ep_devs: bNumEndpoints: 1
    [  427.915934] hub 1-2:1.0: if: ffff88022f9e8800: endpoint devs removed.
    [  427.916158] hub 1-2:1.0: create_intf_ep_devs: if: ffff88022f9e8800 ->ep_devs_created: 0, ->unregistering: 0
    [  427.916434] hub 1-2:1.0: create_intf_ep_devs: bNumEndpoints: 1
    [  427.916609]  ep_81: create, parent hub
    [  427.916632] ------------[ cut here ]------------
    [  427.916644] WARNING: at fs/sysfs/dir.c:477 sysfs_add_one+0x82/0x96()
    [  427.916649] Hardware name: System Product Name
    [  427.916653] sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:12.2/usb1/1-2/1-2:1.0/ep_81'
    [  427.916658] Modules linked in: binfmt_misc kvm_amd kvm powernow_k8 cpufreq_ondemand cpufreq_powersave cpufreq_userspace freq_table cpufreq_conservative ipv6 vfat fat
    +8250_pnp 8250 pcspkr ohci_hcd serial_core k10temp edac_core
    [  427.916694] Pid: 278, comm: khubd Not tainted 2.6.33-rc2-00187-g08d869aa-dirty #13
    [  427.916699] Call Trace:
    
    The problem is caused by a mismatch between the USB core's view of the
    device state and the USB device and xHCI host's view of the device state.
    
    After the device reset and re-configuration, the device and the xHCI host
    think they are using alternate setting 0 of all interfaces.  However, the
    USB core keeps track of the old state, which may include non-zero
    alternate settings.  It uses intf->cur_altsetting to keep the endpoint
    sysfs files for the old state across the reset.
    
    The bandwidth allocation functions need to know what the xHCI host thinks
    the current alternate settings are, so original patch set
    intf->cur_altsetting to the alternate setting 0.  This caused duplicate
    endpoint files to be created.
    
    The solution is to not set intf->cur_altsetting before calling
    usb_set_interface() in usb_reset_and_verify_device().  Instead, we add a
    new flag to struct usb_interface to tell usb_hcd_alloc_bandwidth() to use
    alternate setting 0 as the currently installed alternate setting.
    Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
    Tested-by: NBorislav Petkov <petkovbb@googlemail.com>
    Cc: Alan Stern <stern@rowland.harvard.edu>
    Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
    04a723ea
hcd.c 66.4 KB