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8355b2b308
Some gadget drivers will call usb_ep_queue() more than once before the first queue doesn't finish. However, this driver didn't handle it correctly. So, this patch fixes the behavior of some usbhs_pkt_handle using the "running" flag. Otherwise, the oops below happens if we use g_ncm driver and when the "iperf -u -c host -b 200M" is running. Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = c0004000 [00000000] *pgd=00000000 Internal error: Oops: 80000007 [#1] SMP ARM Modules linked in: usb_f_ncm g_ncm libcomposite u_ether CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 3.17.0-rc1-00008-g8b2be8a-dirty #20 task: c051c7e0 ti: c0512000 task.ti: c0512000 PC is at 0x0 LR is at usbhsf_pkt_handler+0xa8/0x114 pc : [<00000000>] lr : [<c0278fb4>] psr: 60000193 sp : c0513ce8 ip : c0513c58 fp : c0513d24 r10: 00000001 r9 : 00000193 r8 : eebec4a0 r7 : eebec410 r6 : eebe0c6c r5 : 00000000 r4 : ee4a2774 r3 : 00000000 r2 : ee251e00 r1 : c0513cf4 r0 : ee4a2774 Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> 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 ("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.