0de174b56b
USB_MUSB_HDRC depends on USB_GADGET_DUALSPEED. If HDRC is selected but DUALSPEED is not, the kernel oopses: [ 3.132781] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [ 3.141296] pgd = c0004000 [ 3.144134] [00000000] *pgd=00000000 [ 3.147918] Internal error: Oops: 5 [#1] SMP [ 3.152404] Modules linked in: [ 3.155609] CPU: 0 Not tainted (3.1.0-rc9-wl+ #417) [ 3.161132] PC is at composite_setup+0x738/0xbb4 [ 3.165985] LR is at vprintk+0x400/0x47c [ 3.170135] pc : [<c031df90>] lr : [<c004c150>] psr: 60000093 [ 3.170135] sp : c065dd50 ip : dfb1f0fc fp : c065ddbc [ 3.182220] r10: 00000000 r9 : df8fcae8 r8 : df8fcaa0 [ 3.187713] r7 : 00000000 r6 : df8eaa20 r5 : dfae8ea0 r4 : 00000000 [ 3.194580] r3 : df8fcae8 r2 : 00010002 r1 : c065dc40 r0 : 00000047 [ 3.201446] Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel [ 3.209228] Control: 10c53c7d Table: 8000404a DAC: 00000015 [ 3.215270] Process swapper (pid: 0, stack limit = 0xc065c2f8) [ 3.221405] Stack: (0xc065dd50 to 0xc065e000) [...] [ 3.415405] [<c031df90>] (composite_setup+0x738/0xbb4) from [<c0310d18>] (musb_g_ep0_irq+0x9d0/0xaf8) [ 3.425109] [<c0310d18>] (musb_g_ep0_irq+0x9d0/0xaf8) from [<c030fb04>] (musb_interrupt+0xb48/0xc74) [ 3.434722] [<c030fb04>] (musb_interrupt+0xb48/0xc74) from [<c030fc98>] (generic_interrupt+0x68/0x80) [ 3.444458] [<c030fc98>] (generic_interrupt+0x68/0x80) from [<c0095204>] (handle_irq_event_percpu+0x9c/0x234) [ 3.454925] [<c0095204>] (handle_irq_event_percpu+0x9c/0x234) from [<c00953e8>] (handle_irq_event+0x4c/0x6c) [ 3.465270] [<c00953e8>] (handle_irq_event+0x4c/0x6c) from [<c0097e10>] (handle_fasteoi_irq+0xd8/0x110) [ 3.475158] [<c0097e10>] (handle_fasteoi_irq+0xd8/0x110) from [<c0094d2c>] (generic_handle_irq+0x34/0x3c) [ 3.485260] [<c0094d2c>] (generic_handle_irq+0x34/0x3c) from [<c0014ae4>] (handle_IRQ+0x88/0xc8) [ 3.494537] [<c0014ae4>] (handle_IRQ+0x88/0xc8) from [<c00085b0>] (asm_do_IRQ+0x18/0x1c) [ 3.503051] [<c00085b0>] (asm_do_IRQ+0x18/0x1c) from [<c0429e78>] (__irq_svc+0x38/0xc0) This patch changes Kconfig so that USB_GADGET_DUALSPEED is selected automatically by USB_MUSB_HDRC. Signed-off-by: Luciano Coelho <coelho@ti.com> Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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 ("khubd").
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.