On Fri, 13 Jun 2014, Michal Nazarewicz wrote: > While loading g_mass_storage module, the following warning can > trigger: > > WARNING: at drivers/usb/gadget/composite.c: > usb_composite_setup_continue: Unexpected call > Modules linked in: fat vfat minix nls_cp437 nls_iso8859_1 g_mass_storage > [<800179cc>] (unwind_backtrace+0x0/0x104) from [<80619608>] (dump_stack+0x20/0x24) > [<80619608>] (dump_stack+0x20/0x24) from [<80025100>] (warn_slowpath_common+0x64/0x74) > [<80025100>] (warn_slowpath_common+0x64/0x74) from [<800251cc>] (warn_slowpath_fmt+0x40/0x48) > [<800251cc>] (warn_slowpath_fmt+0x40/0x48) from [<7f047774>] (usb_composite_setup_continue+0xb4/0xbc [g_mass_storage]) > [<7f047774>] (usb_composite_setup_continue+0xb4/0xbc [g_mass_storage]) from [<7f047ad4>] (handle_exception+0x358/0x3e4 [g_mass_storage]) > [<7f047ad4>] (handle_exception+0x358/0x3e4 [g_mass_storage]) from [<7f048080>] (fsg_main_thread+0x520/0x157c [g_mass_storage]) > [<7f048080>] (fsg_main_thread+0x520/0x157c [g_mass_storage]) from [<8004bc90>] (kthread+0x98/0x9c) > [<8004bc90>] (kthread+0x98/0x9c) from [<8000faec>] (kernel_thread_exit+0x0/0x8) > > The root cause is that the existing code fails to take into account > the possibility that common->new_fsg can change while > do_set_interface() is running, because the spinlock does not protect > it. > > Change the code so that the common->new_fsg field is protected by the > common->lock spin lock. NAK. common->new_fsg does not need to be protected. Wei's patch is much simpler and will work well. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
