de1e6e799f
devices are required to provide a release method. This patch fixes the following WARN(): [ 42.611159] ------------[ cut here ]------------ [ 42.616025] WARNING: CPU: 0 PID: 1453 at drivers/base/core.c:250 device_release+0x94/0xa0() [ 42.624820] Device 'snd_uac2.0' does not have a release() function, it is broken and must be fixed. [ 42.634328] Modules linked in: usb_f_uac2 g_audio(-) libcomposite configfs xhci_hcd snd_soc_davinci_mcasp snd_soc_edma snd_soc_tlv320aic3x snd_soc_omap snd_soc_evm snd_soc_core dwc3 snd_compress omapdrm snd_pcm_dmaengine snd_pcm snd_timer snd fb_sys_fops lis3lv02d_i2c matrix_keypad dwc3_omap lis3lv02d panel_dpi input_polldev soundcore [ 42.665687] CPU: 0 PID: 1453 Comm: modprobe Tainted: G D 3.17.0-rc6-00448-g9f3d0ec-dirty #188 [ 42.675756] [<c0017338>] (unwind_backtrace) from [<c0012fdc>] (show_stack+0x20/0x24) [ 42.683911] [<c0012fdc>] (show_stack) from [<c0647fbc>] (dump_stack+0x8c/0xa4) [ 42.691526] [<c0647fbc>] (dump_stack) from [<c0049950>] (warn_slowpath_common+0x7c/0xa0) [ 42.700004] [<c0049950>] (warn_slowpath_common) from [<c00499b4>] (warn_slowpath_fmt+0x40/0x48) [ 42.709194] [<c00499b4>] (warn_slowpath_fmt) from [<c0405f7c>] (device_release+0x94/0xa0) [ 42.717794] [<c0405f7c>] (device_release) from [<c032e8e8>] (kobject_cleanup+0x4c/0x7c) [ 42.726189] [<c032e8e8>] (kobject_cleanup) from [<c032e7c8>] (kobject_put+0x60/0x90) [ 42.734316] [<c032e7c8>] (kobject_put) from [<c0406320>] (put_device+0x24/0x28) [ 42.741995] [<c0406320>] (put_device) from [<c040c008>] (platform_device_unregister+0x2c/0x30) [ 42.751061] [<c040c008>] (platform_device_unregister) from [<bf2b6b70>] (afunc_unbind+0x2c/0x68 [usb_f_uac2]) [ 42.761523] [<bf2b6b70>] (afunc_unbind [usb_f_uac2]) from [<bf29dbec>] (remove_config.isra.8+0xe8/0x100 [libcomposite]) [ 42.772868] [<bf29dbec>] (remove_config.isra.8 [libcomposite]) from [<bf29f9a4>] (__composite_unbind+0x48/0xb0 [libcomposite]) [ 42.784855] [<bf29f9a4>] (__composite_unbind [libcomposite]) from [<bf29fa28>] (composite_unbind+0x1c/0x20 [libcomposite]) [ 42.796446] [<bf29fa28>] (composite_unbind [libcomposite]) from [<c04d229c>] (usb_gadget_remove_driver+0x78/0xb0) [ 42.807224] [<c04d229c>] (usb_gadget_remove_driver) from [<c04d2348>] (usb_gadget_unregister_driver+0x74/0xb8) [ 42.817742] [<c04d2348>] (usb_gadget_unregister_driver) from [<bf29db00>] (usb_composite_unregister+0x1c/0x20 [libcomposite]) [ 42.829632] [<bf29db00>] (usb_composite_unregister [libcomposite]) from [<bf2b1084>] (audio_driver_exit+0x14/0x1c [g_audio]) [ 42.841430] [<bf2b1084>] (audio_driver_exit [g_audio]) from [<c00c0fe0>] (SyS_delete_module+0x120/0x1b0) [ 42.851415] [<c00c0fe0>] (SyS_delete_module) from [<c000ed40>] (ret_fast_syscall+0x0/0x48) [ 42.860075] ---[ end trace bb22e678d8d6db7b ]--- root@saruman:~# Signed-off-by: Felipe Balbi <balbi@ti.com>
To understand all the Linux-USB framework, you'll use these resources:
* This source code. This is necessarily an evolving work, and
includes kerneldoc that should help you get a current overview.
("make pdfdocs", and then look at "usb.pdf" for host side and
"gadget.pdf" for peripheral side.) Also, Documentation/usb has
more information.
* The USB 2.0 specification (from www.usb.org), with supplements
such as those for USB OTG and the various device classes.
The USB specification has a good overview chapter, and USB
peripherals conform to the widely known "Chapter 9".
* Chip specifications for USB controllers. Examples include
host controllers (on PCs, servers, and more); peripheral
controllers (in devices with Linux firmware, like printers or
cell phones); and hard-wired peripherals like Ethernet adapters.
* Specifications for other protocols implemented by USB peripheral
functions. Some are vendor-specific; others are vendor-neutral
but just standardized outside of the www.usb.org team.
Here is a list of what each subdirectory here is, and what is contained in
them.
core/ - This is for the core USB host code, including the
usbfs files and the hub class driver ("hub_wq").
host/ - This is for USB host controller drivers. This
includes UHCI, OHCI, EHCI, and others that might
be used with more specialized "embedded" systems.
gadget/ - This is for USB peripheral controller drivers and
the various gadget drivers which talk to them.
Individual USB driver directories. A new driver should be added to the
first subdirectory in the list below that it fits into.
image/ - This is for still image drivers, like scanners or
digital cameras.
../input/ - This is for any driver that uses the input subsystem,
like keyboard, mice, touchscreens, tablets, etc.
../media/ - This is for multimedia drivers, like video cameras,
radios, and any other drivers that talk to the v4l
subsystem.
../net/ - This is for network drivers.
serial/ - This is for USB to serial drivers.
storage/ - This is for USB mass-storage drivers.
class/ - This is for all USB device drivers that do not fit
into any of the above categories, and work for a range
of USB Class specified devices.
misc/ - This is for all USB device drivers that do not fit
into any of the above categories.