user/sven/linux.git/drivers/usb/core/driver.c, branch v3.18.37

USB: leave LPM alone if possible when binding/unbinding interface drivers

2016-06-03T15:30:33Z

[ Upstream commit 6fb650d43da3e7054984dc548eaa88765a94d49f ] When a USB driver is bound to an interface (either through probing or by claiming it) or is unbound from an interface, the USB core always disables Link Power Management during the transition and then re-enables it afterward. The reason is because the driver might want to prevent hub-initiated link power transitions, in which case the HCD would have to recalculate the various LPM parameters. This recalculation takes place when LPM is re-enabled and the new parameters are sent to the device and its parent hub. However, if the driver does not want to prevent hub-initiated link power transitions then none of this work is necessary. The parameters don't need to be recalculated, and LPM doesn't need to be disabled and re-enabled. It turns out that disabling and enabling LPM can be time-consuming, enough so that it interferes with user programs that want to claim and release interfaces rapidly via usbfs. Since the usbfs kernel driver doesn't set the disable_hub_initiated_lpm flag, we can speed things up and get the user programs to work by leaving LPM alone whenever the flag isn't set. And while we're improving the way disable_hub_initiated_lpm gets used, let's also fix its kerneldoc. Signed-off-by: Alan Stern Tested-by: Matthew Giassa CC: Mathias Nyman CC: Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

USB: usb_driver_claim_interface: add sanity checking

2016-04-18T12:49:35Z

[ Upstream commit 0b818e3956fc1ad976bee791eadcbb3b5fec5bfd ] Attacks that trick drivers into passing a NULL pointer to usb_driver_claim_interface() using forged descriptors are known. This thwarts them by sanity checking. Signed-off-by: Oliver Neukum CC: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

USB: add flag for HCDs that can't receive wakeup requests (isp1760-hcd)

2015-03-06T22:53:00Z

commit 074f9dd55f9cab1b82690ed7e44bcf38b9616ce0 upstream. Currently the USB stack assumes that all host controller drivers are capable of receiving wakeup requests from downstream devices. However, this isn't true for the isp1760-hcd driver, which means that it isn't safe to do a runtime suspend of any device attached to a root-hub port if the device requires wakeup. This patch adds a "cant_recv_wakeups" flag to the usb_hcd structure and sets the flag in isp1760-hcd. The core is modified to prevent a direct child of the root hub from being put into runtime suspend with wakeup enabled if the flag is set. Signed-off-by: Alan Stern Tested-by: Nicolas Pitre Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

USB: don't cancel queued resets when unbinding drivers

2015-03-06T22:53:00Z

commit 524134d422316a59d5464ccbc12036bbe90c5563 upstream. The USB stack provides a mechanism for drivers to request an asynchronous device reset (usb_queue_reset_device()). The mechanism uses a work item (reset_ws) embedded in the usb_interface structure used by the driver, and the reset is carried out by a work queue routine. The asynchronous reset can race with driver unbinding. When this happens, we try to cancel the queued reset before unbinding the driver, on the theory that the driver won't care about any resets once it is unbound. However, thanks to the fact that lockdep now tracks work queue accesses, this can provoke a lockdep warning in situations where the device reset causes another interface's driver to be unbound; see http://marc.info/?l=linux-usb&m=141893165203776&w=2 for an example. The reason is that the work routine for reset_ws in one interface calls cancel_queued_work() for the reset_ws in another interface. Lockdep thinks this might lead to a work routine trying to cancel itself. The simplest solution is not to cancel queued resets when unbinding drivers. This means we now need to acquire a reference to the usb_interface when queuing a reset_ws work item and to drop the reference when the work routine finishes. We also need to make sure that the usb_interface structure doesn't outlive its parent usb_device; this means acquiring and dropping a reference when the interface is created and destroyed. In addition, cancelling a queued reset can fail (if the device is in the middle of an earlier reset), and this can cause usb_reset_device() to try to rebind an interface that has been deallocated (see http://marc.info/?l=linux-usb&m=142175717016628&w=2 for details). Acquiring the extra references prevents this failure. Signed-off-by: Alan Stern Reported-by: Russell King - ARM Linux Reported-by: Olivier Sobrie Tested-by: Olivier Sobrie Signed-off-by: Greg Kroah-Hartman

USB: shutdown all URBs after controller death

2014-07-17T23:59:27Z

When a host controller dies, we don't need to wait for a driver to time out. We can shut down its URBs immediately. Without this change, we can end up waiting 30 seconds for a mass-storage transfer to time out. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman

USB: Avoid runtime suspend loops for HCDs that can't handle suspend/resume

2014-05-23T19:06:00Z

Not all host controller drivers have bus-suspend and bus-resume methods. When one doesn't, it will cause problems if runtime PM is enabled in the kernel. The PM core will attempt to suspend the controller's root hub, the suspend will fail because there is no bus-suspend routine, and a -EBUSY error code will be returned to the PM core. This will cause the suspend attempt to be repeated shortly thereafter, in a never-ending loop. Part of the problem is that the original error code -ENOENT gets changed to -EBUSY in usb_runtime_suspend(), on the grounds that the PM core will interpret -ENOENT as meaning that the root hub has gotten into a runtime-PM error state. While this change is appropriate for real USB devices, it's not such a good idea for a root hub. In fact, considering the root hub to be in a runtime-PM error state would not be far from the truth. Therefore this patch updates usb_runtime_suspend() so that it adjusts error codes only for non-root-hub devices. Furthermore, the patch attempts to prevent the problem from occurring in the first place by not enabling runtime PM by default for root hubs whose host controller driver doesn't have bus_suspend and bus_resume methods. Signed-off-by: Alan Stern Reported-by: Will Deacon Tested-by: Will Deacon CC: Signed-off-by: Greg Kroah-Hartman

USB: unbind all interfaces before rebinding any

2014-03-17T23:08:27Z

When a driver doesn't have pre_reset, post_reset, or reset_resume methods, the USB core unbinds that driver when its device undergoes a reset or a reset-resume, and then rebinds it afterward. The existing straightforward implementation can lead to problems, because each interface gets unbound and rebound before the next interface is handled. If a driver claims additional interfaces, the claim may fail because the old binding instance may still own the additional interface when the new instance tries to claim it. This patch fixes the problem by first unbinding all the interfaces that are marked (i.e., their needs_binding flag is set) and then rebinding all of them. The patch also makes the helper functions in driver.c a little more uniform and adjusts some out-of-date comments. Signed-off-by: Alan Stern Reported-and-tested-by: "Poulain, Loic" Cc: stable Signed-off-by: Greg Kroah-Hartman

usb-core: Free bulk streams on interface release

2014-03-04T23:38:03Z

Documentation/usb/bulk-streams.txt says: All stream IDs will be deallocated when the driver releases the interface, to ensure that drivers that don't support streams will be able to use the endpoint This commit actually implements this. Signed-off-by: Hans de Goede Signed-off-by: Sarah Sharp

Merge 3.14-rc3 into usb-next

2014-02-18T17:27:12Z

We want the fixes in this branch as well. Signed-off-by: Greg Kroah-Hartman

usb: core: let dynamic ids override static ids

2014-02-07T22:24:24Z

This modifies the probing order so that any matching dynamic entry always will be used, even if the driver has a matching static entry. It is sometimes useful to dynamically update existing device entries. With the new ability to set the dynamic entry driver_info field, this can be used to test new additions to class driver exception lists or proposed changes to existing static per-device driver_info entries. Signed-off-by: Bjørn Mork Signed-off-by: Greg Kroah-Hartman