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commitdec3c23c9aupstream. Commitf16443a034("USB: gadgetfs, dummy-hcd, net2280: fix locking for callbacks") was based on a serious misunderstanding. It introduced regressions into both the dummy-hcd and net2280 drivers. The problem in dummy-hcd was fixed by commit7dbd8f4cab("USB: dummy-hcd: Fix erroneous synchronization change"), but the problem in net2280 remains. Namely: the ->disconnect(), ->suspend(), ->resume(), and ->reset() callbacks must be invoked without the private lock held; otherwise a deadlock will occur when the callback routine tries to interact with the UDC driver. This patch largely is a reversion of the relevant parts off16443a034. It also drops the private lock around the calls to ->suspend() and ->resume() (something the earlier patch forgot to do). This is safe from races with device interrupts because it occurs within the interrupt handler. Finally, the patch changes where the ->disconnect() callback is invoked when net2280_pullup() turns the pullup off. Rather than making the callback from within stop_activity() at a time when dropping the private lock could be unsafe, the callback is moved to a point after the lock has already been dropped. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Fixes:f16443a034("USB: gadgetfs, dummy-hcd, net2280: fix locking for callbacks") Reported-by: D. Ziesche <dziesche@zes.com> Tested-by: D. Ziesche <dziesche@zes.com> CC: <stable@vger.kernel.org> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.