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path: root/drivers/usb/gadget/function/f_printer.c
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2015-08-14Merge tag 'usb-for-v4.3' of ↵Greg Kroah-Hartman
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>
2015-08-03usb: gadget: f_printer: fix deadlock caused by nested spinlockFupan Li
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>
2015-07-27usb: gadget: f_printer: actually limit the number of instancesAndrzej Pietrasiewicz
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>
2015-03-13usb: gadget: f_printer: use non-zero flag for bitwise andAndrzej Pietrasiewicz
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>
2015-03-13usb: gadget: printer: use after free in gprinter_alloc_inst()Dan Carpenter
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>
2015-03-13usb: gadget: printer: delete some dead codeDan Carpenter
"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>
2015-03-10usb: gadget: printer: add configfs supportAndrzej Pietrasiewicz
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>
2015-03-10usb: gadget: f_printer: remove compatibility layerAndrzej Pietrasiewicz
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>
2015-03-10usb: gadget: f_printer: convert to new function interface with backward ↵Andrzej Pietrasiewicz
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>
2015-03-10usb: gadget: printer: factor out f_printerAndrzej Pietrasiewicz
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>