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authorSarah Sharp <sarah.a.sharp@linux.intel.com>2010-01-06 13:16:51 -0500
committerGreg Kroah-Hartman <gregkh@suse.de>2010-01-20 18:24:35 -0500
commit04a723ea9c53ba608b0411aa36948bb57c51a08e (patch)
tree1a5d7395ccc864b8bdf8688396688951e28a4ca8
parentb132b04e193908a94d95065d0628f8fb0159cc55 (diff)
USB: Fix duplicate sysfs problem after device reset.
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-g08d869a-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: Sarah Sharp <sarah.a.sharp@linux.intel.com> Tested-by: Borislav Petkov <petkovbb@googlemail.com> Cc: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/usb/core/hcd.c18
-rw-r--r--drivers/usb/core/hub.c15
-rw-r--r--include/linux/usb.h1
3 files changed, 24 insertions, 10 deletions
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 0495fa651225..80995ef0868c 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1684,6 +1684,24 @@ int usb_hcd_alloc_bandwidth(struct usb_device *udev,
1684 } 1684 }
1685 } 1685 }
1686 if (cur_alt && new_alt) { 1686 if (cur_alt && new_alt) {
1687 struct usb_interface *iface = usb_ifnum_to_if(udev,
1688 cur_alt->desc.bInterfaceNumber);
1689
1690 if (iface->resetting_device) {
1691 /*
1692 * The USB core just reset the device, so the xHCI host
1693 * and the device will think alt setting 0 is installed.
1694 * However, the USB core will pass in the alternate
1695 * setting installed before the reset as cur_alt. Dig
1696 * out the alternate setting 0 structure, or the first
1697 * alternate setting if a broken device doesn't have alt
1698 * setting 0.
1699 */
1700 cur_alt = usb_altnum_to_altsetting(iface, 0);
1701 if (!cur_alt)
1702 cur_alt = &iface->altsetting[0];
1703 }
1704
1687 /* Drop all the endpoints in the current alt setting */ 1705 /* Drop all the endpoints in the current alt setting */
1688 for (i = 0; i < cur_alt->desc.bNumEndpoints; i++) { 1706 for (i = 0; i < cur_alt->desc.bNumEndpoints; i++) {
1689 ret = hcd->driver->drop_endpoint(hcd, udev, 1707 ret = hcd->driver->drop_endpoint(hcd, udev,
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index b9f5fcd713e2..35cc8b9ba1f5 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -3695,19 +3695,14 @@ static int usb_reset_and_verify_device(struct usb_device *udev)
3695 usb_enable_interface(udev, intf, true); 3695 usb_enable_interface(udev, intf, true);
3696 ret = 0; 3696 ret = 0;
3697 } else { 3697 } else {
3698 /* We've just reset the device, so it will think alt 3698 /* Let the bandwidth allocation function know that this
3699 * setting 0 is installed. For usb_set_interface() to 3699 * device has been reset, and it will have to use
3700 * work properly, we need to set the current alternate 3700 * alternate setting 0 as the current alternate setting.
3701 * interface setting to 0 (or the first alt setting, if
3702 * the device doesn't have alt setting 0).
3703 */ 3701 */
3704 intf->cur_altsetting = 3702 intf->resetting_device = 1;
3705 usb_find_alt_setting(config, i, 0);
3706 if (!intf->cur_altsetting)
3707 intf->cur_altsetting =
3708 &config->intf_cache[i]->altsetting[0];
3709 ret = usb_set_interface(udev, desc->bInterfaceNumber, 3703 ret = usb_set_interface(udev, desc->bInterfaceNumber,
3710 desc->bAlternateSetting); 3704 desc->bAlternateSetting);
3705 intf->resetting_device = 0;
3711 } 3706 }
3712 if (ret < 0) { 3707 if (ret < 0) {
3713 dev_err(&udev->dev, "failed to restore interface %d " 3708 dev_err(&udev->dev, "failed to restore interface %d "
diff --git a/include/linux/usb.h b/include/linux/usb.h
index e101a2d04d75..d7ace1b80f09 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -192,6 +192,7 @@ struct usb_interface {
192 unsigned needs_altsetting0:1; /* switch to altsetting 0 is pending */ 192 unsigned needs_altsetting0:1; /* switch to altsetting 0 is pending */
193 unsigned needs_binding:1; /* needs delayed unbind/rebind */ 193 unsigned needs_binding:1; /* needs delayed unbind/rebind */
194 unsigned reset_running:1; 194 unsigned reset_running:1;
195 unsigned resetting_device:1; /* true: bandwidth alloc after reset */
195 196
196 struct device dev; /* interface specific device info */ 197 struct device dev; /* interface specific device info */
197 struct device *usb_dev; 198 struct device *usb_dev;