10 Commits

Author SHA1 Message Date
Greg Kroah-Hartman
a3fbedf98f usb: patches for v4.3 merge window
New support for Allwinne SoC on the MUSB driver has been added to the list of
 glue layers. MUSB also got support for building all DMA engines in one binary;
 this will be great for distros.
 
 DWC3 now has no trace of dev_dbg()/dev_vdbg() usage. We will rely solely on
 tracing to debug DWC3. There was also a fix for memory corruption with EP0 when
 maxpacket size transfers are > 512 bytes.
 
 Robert's EP capabilities flags is making EP selection a lot simpler. UDCs are
 now required to set these flags up when adding endpoints to the framework.
 
 Other than these, we have the usual set of miscelaneous cleanups and minor
 fixes.
 
 Signed-off-by: Felipe Balbi <balbi@ti.com>
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Merge tag 'usb-for-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb into usb-next

Felipe writes:

usb: patches for v4.3 merge window

New support for Allwinne SoC on the MUSB driver has been added to the list of
glue layers. MUSB also got support for building all DMA engines in one binary;
this will be great for distros.

DWC3 now has no trace of dev_dbg()/dev_vdbg() usage. We will rely solely on
tracing to debug DWC3. There was also a fix for memory corruption with EP0 when
maxpacket size transfers are > 512 bytes.

Robert's EP capabilities flags is making EP selection a lot simpler. UDCs are
now required to set these flags up when adding endpoints to the framework.

Other than these, we have the usual set of miscelaneous cleanups and minor
fixes.

Signed-off-by: Felipe Balbi <balbi@ti.com>
2015-08-14 16:41:11 -07:00
Fupan Li
a24b071bb4 usb: gadget: f_printer: fix deadlock caused by nested spinlock
Function printer_func_disable() has called spinlock on printer_dev->lock,
and it'll call function chain of

    printer_reset_interface()
        |
	+---dwc3_gadget_ep_disable()
	        |
                +---__dwc3_gadget_ep_disable()
                        |
                        +---dwc3_remove_requests()
                                |
                                +---dwc3_gadget_giveback()
                                        |
                                        +---rx_complete()

in the protected block.

However, rx_complete() in f_printer.c calls spinlock on printer_dev->lock
again, which will cause system hang.

The following steps can reproduce this hang:

1. Build the test program from Documentation/usb/gadget_printer.txt as
   g_printer
2. Plug in the USB device to a host(such as Ubuntu).
3. on the USB device system run:
   #modprobe g_printer.ko
   #./g_printer -read_data

4. Unplug the USB device from the host

   The system will hang later.

In order to avoid this deadlock, moving the spinlock from
printer_func_disable() into printer_reset_interface() and excluding the block
of calling dwc3_gadget_ep_disable(), in which the critical resource will be
protected by its spinlock in rx_complete().

This commit will fix the system hang with the following calltrace:

INFO: rcu_preempt detected stalls on CPUs/tasks: { 3} (detected by 0, t=21006 jiffies, g=524, c=523, q=2)
sending NMI to all CPUs:
NMI backtrace for cpu 3
CPU: 3 PID: 718 Comm: irq/22-dwc3 Not tainted 3.10.38-ltsi-WR6.0.0.11_standard #2
Hardware name: Intel Corp. VALLEYVIEW B3 PLATFORM/NOTEBOOK, BIOS BYTICRB1.86C.0092.R32.1410021707 10/02/2014
task: f44f4c20 ti: f40f6000 task.ti: f40f6000
EIP: 0060:[<c1824955>] EFLAGS: 00000097 CPU: 3
EIP is at _raw_spin_lock_irqsave+0x35/0x40
EAX: 00000076 EBX: f80fad00 ECX: 00000076 EDX: 00000075
ESI: 00000096 EDI: ffffff94 EBP: f40f7e20 ESP: f40f7e18
 DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
CR0: 8005003b CR2: b77ac000 CR3: 01c30000 CR4: 001007f0
DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
DR6: ffff0ff0 DR7: 00000400
Stack:
 f474a720 f80fad00 f40f7e3c f80f93cc c135d486 00000000 f474a720 f468fb00
 f4bea894 f40f7e54 f7e35f19 ffffff00 f468fb00 f468fb24 00000086 f40f7e64
 f7e36577 f468fb00 f4bea810 f40f7e74 f7e365a8 f468fb00 f4bea894 f40f7e9c
Call Trace:
 [<f80f93cc>] rx_complete+0x1c/0xb0 [g_printer]
 [<c135d486>] ? vsnprintf+0x166/0x390
 [<f7e35f19>] dwc3_gadget_giveback+0xc9/0xf0 [dwc3]
 [<f7e36577>] dwc3_remove_requests+0x57/0x70 [dwc3]
 [<f7e365a8>] __dwc3_gadget_ep_disable+0x18/0x60 [dwc3]
 [<f7e366e9>] dwc3_gadget_ep_disable+0x89/0xf0 [dwc3]
 [<f80f9031>] printer_reset_interface+0x31/0x50 [g_printer]
 [<f80f9270>] printer_func_disable+0x20/0x30 [g_printer]
 [<f80e6d8b>] composite_disconnect+0x4b/0x90 [libcomposite]
 [<f7e39a8b>] dwc3_disconnect_gadget+0x38/0x43 [dwc3]
 [<f7e39ad4>] dwc3_gadget_disconnect_interrupt+0x3e/0x5a [dwc3]
 [<f7e373b8>] dwc3_thread_interrupt+0x5c8/0x610 [dwc3]
 [<c10ac518>] irq_thread_fn+0x18/0x30
 [<c10ac800>] irq_thread+0x100/0x130
 [<c10ac500>] ? irq_finalize_oneshot.part.29+0xb0/0xb0
 [<c10ac650>] ? wake_threads_waitq+0x40/0x40
 [<c10ac700>] ? irq_thread_dtor+0xb0/0xb0
 [<c1057224>] kthread+0x94/0xa0
 [<c182b337>] ret_from_kernel_thread+0x1b/0x28
 [<c1057190>] ? kthread_create_on_node+0xc0/0xc0

Signed-off-by: Fupan Li <fupan.li@windriver.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2015-08-03 09:49:47 -05:00
Andrzej Pietrasiewicz
4248bd7d3e usb: gadget: f_printer: actually limit the number of instances
There is a predefined maximum number of printer instances, currently 4.
A chrdev region is allocated accordingly, but with configfs the user
can create as many printer function directories as they like. To make the
number of printer  instances consistent with the number of allocated
minors, the limit is enforced at directory creation time.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2015-07-27 10:19:50 -05:00
Andrzej Pietrasiewicz
fbdecad99c usb: gadget: f_printer: use non-zero flag for bitwise and
USB_DIR_OUT happens to be zero, so the result of bitwise and is always 0.
Consequently, break will never happen in the SOFT_RESET case.
This patch uses a compatible condition with a non-zero USB_DIR_IN,
which might or might not evaluate to zero.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2015-03-13 10:41:05 -05:00
Dan Carpenter
2bb2077ee6 usb: gadget: printer: use after free in gprinter_alloc_inst()
There was a missing goto so we free "opts" and then dereference it.

Fixes: ee1cd515e889 ('usb: gadget: printer: add configfs support')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2015-03-13 10:41:01 -05:00
Dan Carpenter
fdb51e3d97 usb: gadget: printer: delete some dead code
"num" is a u16 so it can't go higher than 65535.  kstrtou16() has a
range check built in so this is already handled.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2015-03-13 10:40:57 -05:00
Andrzej Pietrasiewicz
ee1cd515e8 usb: gadget: printer: add configfs support
Add support for configfs interface so that f_printer can be used as a
component of usb gadgets composed with it.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2015-03-10 15:33:41 -05:00
Andrzej Pietrasiewicz
d85dc4824c usb: gadget: f_printer: remove compatibility layer
There are no old interface users left, so it can be removed.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2015-03-10 15:33:41 -05:00
Andrzej Pietrasiewicz
b26394bd56 usb: gadget: f_printer: convert to new function interface with backward compatibility
In order to add configfs support, a usb function must be converted to use
the new interface. This patch converts the function to the new interface
and provides backward compatiblity layer, which can be removed after
all its users are converted to use the new interface.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2015-03-10 15:33:40 -05:00
Andrzej Pietrasiewicz
b185f01a9a usb: gadget: printer: factor out f_printer
The legacy printer gadget now contains both a reusable printer function
and legacy gadget proper implementations interwoven, but logically
separate. This patch factors out a reusable f_printer.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2015-03-10 15:33:40 -05:00