linux/drivers/usb/gadget
wenlin.kang 2c2b04253b usb: gadget: printer: fix possible deadlock
The problem occurs in follow path.

printer_read()
	|
	+---setup_rx_reqs()
		|
		+---usb_ep_queue()
			|
			+---...
				|
				+---rx_complete()

Although it is clear from code, we can't get it normally.
only when we enable some spin_lock debug config option, we can find it.
eg:
BUG: spinlock lockup on CPU#0, g_printer_test_/584
 lock: bf05e158, .magic: dead4ead, .owner: g_printer_test_/584, .owner_cpu: 0
[<c0016e1c>] (unwind_backtrace+0x0/0x104) from [<c067aef8>] (dump_stack+0x20/0x24)
[<c067aef8>] (dump_stack+0x20/0x24) from [<c0680bec>] (spin_dump+0x8c/0x94)
[<c0680bec>] (spin_dump+0x8c/0x94) from [<c039071c>] (do_raw_spin_lock+0x128/0x154)
[<c039071c>] (do_raw_spin_lock+0x128/0x154) from [<c0685618>] (_raw_spin_lock_irqsave+0x64/0x70)
[<c0685618>] (_raw_spin_lock_irqsave+0x64/0x70) from [<bf05b4e8>] (rx_complete+0x54/0x10c [g_printer])
[<bf05b4e8>] (rx_complete+0x54/0x10c [g_printer]) from [<c0480478>] (musb_g_giveback+0x78/0x88)
[<c0480478>] (musb_g_giveback+0x78/0x88) from [<c048060c>] (rxstate+0xa0/0x10c)
[<c048060c>] (rxstate+0xa0/0x10c) from [<c0480d50>] (musb_ep_restart+0x44/0x70)
[<c0480d50>] (musb_ep_restart+0x44/0x70) from [<c0480fe4>] (musb_gadget_queue+0xe8/0xf8)
[<c0480fe4>] (musb_gadget_queue+0xe8/0xf8) from [<bf05b2b0>] (setup_rx_reqs+0xa4/0x178 [g_printer])
[<bf05b2b0>] (setup_rx_reqs+0xa4/0x178 [g_printer]) from [<bf05bb58>] (printer_read+0x9c/0x3f4 [g_printer])
[<bf05bb58>] (printer_read+0x9c/0x3f4 [g_printer]) from [<c01387f0>] (vfs_read+0xb4/0x144)
[<c01387f0>] (vfs_read+0xb4/0x144) from [<c01388d0>] (sys_read+0x50/0x124)
[<c01388d0>] (sys_read+0x50/0x124) from [<c000e900>] (ret_fast_syscall+0x0/0x3c)

The root cause is that we use the same lock two time in a path, so to avoid
the deadlock, we need to unlock in setup_rx_reqs(), and only unlock.

Signed-off-by: wenlin.kang <wenlin.kang@windriver.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2014-02-18 10:52:54 -06:00
..
acm_ms.c usb: gadget: fix up some comments about CONFIG_USB_DEBUG 2013-12-20 09:51:24 -06:00
amd5536udc.c usb: delete non-required instances of include <linux/init.h> 2014-01-08 15:01:39 -08:00
amd5536udc.h
at91_udc.c usb: delete non-required instances of include <linux/init.h> 2014-01-08 15:01:39 -08:00
at91_udc.h usb: gadget: at91_udc: add usb_clk for transition to common clk framework 2013-08-02 15:17:03 +03:00
atmel_usba_udc.c ARM: SoC cleanups for 3.14 2014-01-23 18:36:55 -08:00
atmel_usba_udc.h USB: gadget: atmel_usba: add DT support 2013-05-24 07:14:45 +08:00
audio.c
bcm63xx_udc.c usb: delete non-required instances of include <linux/init.h> 2014-01-08 15:01:39 -08:00
cdc2.c usb: gadget: cdc2: fix conversion to new interface of f_ecm 2013-09-17 10:38:52 -05:00
composite.c usb: gadget: should use u16 type variable to store MaxPower 2013-12-19 09:27:43 -06:00
config.c
configfs.c usb: gadget: configfs: include appropriate header file in configfs.c 2013-12-19 09:27:42 -06:00
configfs.h usb: gadget: configfs: add a method to unregister the gadget 2013-10-01 09:50:22 -05:00
dbgp.c
dummy_hcd.c usb: gadget: add "maxpacket_limit" field to struct usb_ep 2013-12-17 13:17:41 -06:00
epautoconf.c usb: delete non-required instances of include <linux/init.h> 2014-01-08 15:01:39 -08:00
ether.c usb: gadget: ether: put_usb_function on unbind 2013-07-25 20:35:23 +03:00
f_acm.c usb: acm gadget: Null termintate strings table 2013-08-30 11:10:36 -07:00
f_ecm.c usb: gadget: f_ecm: remove compatibility layer 2013-12-12 13:43:36 -06:00
f_eem.c usb: gadget: f_eem: Staticize eem_alloc 2013-09-17 11:06:50 -05:00
f_fs.c usb: gadget: f_fs: fix sparse warning 2013-12-12 13:43:40 -06:00
f_hid.c usb: gadget: factor out alloc_ep_req 2013-11-26 13:41:32 -06:00
f_loopback.c usb: gadget: f_loopback: Fix sparse warning 2013-12-17 13:17:42 -06:00
f_mass_storage.c usb: gadget: f_mass_storage: Fix sparse warning 2013-12-17 13:17:43 -06:00
f_mass_storage.h usb: gadget: f_mass_storage: remove compatibility layer 2013-10-10 10:24:53 -05:00
f_midi.c usb: gadget: factor out alloc_ep_req 2013-11-26 13:41:32 -06:00
f_ncm.c usb: gadget: f_ncm: Fix sparse warning 2013-12-17 13:17:43 -06:00
f_obex.c usb: gadget: f_obex: Fix sparse warning 2013-12-17 13:17:43 -06:00
f_phonet.c usb: gadget: f_phonet: Fix sparse warning 2013-12-17 13:17:44 -06:00
f_rndis.c usb: gadget: rndis: merge u_rndis.ko with usb_f_rndis.ko 2013-12-12 13:43:38 -06:00
f_serial.c usb: gadget: f_serial: Fix sparse warning 2013-12-17 13:17:44 -06:00
f_sourcesink.c usb: gadget: f_sourcesink: Fix sparse warning 2013-12-17 13:17:44 -06:00
f_subset.c usb: gadget: f_subset: remove compatibility layer 2013-12-12 13:43:37 -06:00
f_uac1.c usb: gadget: f_uac1: Staticize local functions 2013-08-09 16:34:19 +03:00
f_uac2.c USB: gadget: f_uac2: Fix broken prm to uac2 mapping 2013-06-10 17:10:23 +03:00
f_uvc.c Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2013-07-13 12:09:57 -07:00
f_uvc.h
fotg210-udc.c usb: gadget: add "maxpacket_limit" field to struct usb_ep 2013-12-17 13:17:41 -06:00
fotg210.h usb: gadget: add Faraday fotg210_udc driver 2013-06-10 17:58:11 +03:00
fsl_mxc_udc.c usb: gadget: use dev_get_platdata() 2013-07-30 11:18:46 +03:00
fsl_qe_udc.c usb: delete non-required instances of include <linux/init.h> 2014-01-08 15:01:39 -08:00
fsl_qe_udc.h
fsl_udc_core.c usb: gadget: add "maxpacket_limit" field to struct usb_ep 2013-12-17 13:17:41 -06:00
fsl_usb2_udc.h
functions.c
fusb300_udc.c usb: gadget: add "maxpacket_limit" field to struct usb_ep 2013-12-17 13:17:41 -06:00
fusb300_udc.h
g_ffs.c usb: gadget: g_ffs: convert to new interface of f_fs 2013-12-12 13:43:39 -06:00
g_zero.h usb: gadget: f_sourcesink: add configfs support 2013-11-26 13:47:41 -06:00
gadget_chips.h
gmidi.c
goku_udc.c usb: delete non-required instances of include <linux/init.h> 2014-01-08 15:01:39 -08:00
goku_udc.h
gr_udc.c usb: delete non-required instances of include <linux/init.h> 2014-01-08 15:01:39 -08:00
gr_udc.h usb: gadget: Add UDC driver for Aeroflex Gaisler GRUSBDC 2013-12-23 19:26:13 -06:00
hid.c usb: gadget: use dev_get_platdata() 2013-07-30 11:18:46 +03:00
inode.c Merge git://git.kvack.org/~bcrl/aio-next 2013-09-13 10:55:58 -07:00
Kconfig usb: gadget: s3c-hsotg: fix build on x86 and other architectures 2014-02-18 10:52:52 -06:00
lpc32xx_udc.c usb: gadget: add "maxpacket_limit" field to struct usb_ep 2013-12-17 13:17:41 -06:00
m66592-udc.c usb: gadget: add "maxpacket_limit" field to struct usb_ep 2013-12-17 13:17:41 -06:00
m66592-udc.h
Makefile usb: gadget: Add UDC driver for Aeroflex Gaisler GRUSBDC 2013-12-23 19:26:13 -06:00
mass_storage.c usb: gadget: mass_storage: convert to new interface of f_mass_storage 2013-10-10 10:24:10 -05:00
multi.c usb: gadget: fix up some comments about CONFIG_USB_DEBUG 2013-12-20 09:51:24 -06:00
mv_u3d_core.c usb: delete non-required instances of include <linux/init.h> 2014-01-08 15:01:39 -08:00
mv_u3d.h
mv_udc_core.c usb: delete non-required instances of include <linux/init.h> 2014-01-08 15:01:39 -08:00
mv_udc.h
ncm.c usb: gadget: ncm: convert to new function interface 2013-06-10 17:12:52 +03:00
ndis.h
net2272.c usb: gadget: add "maxpacket_limit" field to struct usb_ep 2013-12-17 13:17:41 -06:00
net2272.h
net2280.c usb: gadget: add "maxpacket_limit" field to struct usb_ep 2013-12-17 13:17:41 -06:00
net2280.h
nokia.c usb: gadget: nokia: fix error recovery path for optional functions 2013-12-17 13:17:41 -06:00
omap_udc.c usb: delete non-required instances of include <linux/init.h> 2014-01-08 15:01:39 -08:00
omap_udc.h
pch_udc.c usb: gadget: add "maxpacket_limit" field to struct usb_ep 2013-12-17 13:17:41 -06:00
printer.c usb: gadget: printer: fix possible deadlock 2014-02-18 10:52:54 -06:00
pxa25x_udc.c usb: delete non-required instances of include <linux/init.h> 2014-01-08 15:01:39 -08:00
pxa25x_udc.h
pxa27x_udc.c usb: gadget: add "maxpacket_limit" field to struct usb_ep 2013-12-17 13:17:41 -06:00
pxa27x_udc.h
r8a66597-udc.c usb: gadget: add "maxpacket_limit" field to struct usb_ep 2013-12-17 13:17:41 -06:00
r8a66597-udc.h
rndis.c usb: delete non-required instances of include <linux/init.h> 2014-01-08 15:01:39 -08:00
rndis.h usb: gadget: rndis: init & exit rndis at module load/unload 2013-06-10 17:58:09 +03:00
s3c2410_udc.c usb: gadget: s3c2410_udc: Fix build error 2014-02-18 10:52:53 -06:00
s3c2410_udc.h
s3c-hsotg.c usb: gadget: s3c-hsotg: use %pad for dma_addr_t 2014-02-18 10:52:52 -06:00
s3c-hsotg.h usb: gadget: s3c-hsotg: get phy bus width from phy subsystem 2013-12-23 14:31:49 -06:00
s3c-hsudc.c usb: gadget: s3c-hsudc: remove unused label 2014-02-18 10:52:53 -06:00
serial.c
storage_common.c usb: gadget: storage_common: pass filesem to fsg_store_cdrom 2013-10-15 06:52:08 -05:00
storage_common.h usb: gadget: mass storage: fix return of delayed status 2013-11-25 10:56:33 -06:00
tcm_usb_gadget.c usb: gadget: tcm_usb_gadget: mark bot_cleanup_old_alt static 2013-11-25 11:19:41 -06:00
tcm_usb_gadget.h
u_ecm.h usb: gadget: f_ecm: add configfs support 2013-06-10 17:27:54 +03:00
u_eem.h usb: gadget: f_eem: add configfs support 2013-06-10 17:58:00 +03:00
u_ether_configfs.h usb: gadget: add helpers for configfs support for USB Ethernet 2013-06-10 17:15:43 +03:00
u_ether.c usb: gadget: update some out of date comments 2013-11-26 10:58:17 -06:00
u_ether.h usb: gadget: f_rndis: remove compatibility layer 2013-12-12 13:43:37 -06:00
u_f.c usb: gadget: factor out alloc_ep_req 2013-11-26 13:41:32 -06:00
u_f.h usb: gadget: factor out alloc_ep_req 2013-11-26 13:41:32 -06:00
u_fs.h usb: gadget: FunctionFS: add configfs support 2013-12-12 13:43:40 -06:00
u_gether.h usb: gadget: f_subset: add configfs support 2013-06-10 17:58:08 +03:00
u_ncm.h usb: gadget: f_ncm: add configfs support 2013-06-10 17:15:02 +03:00
u_phonet.h usb: gadget: f_phonet: remove compatibility layer 2013-06-10 17:31:55 +03:00
u_rndis.h usb: gadget: rndis: merge u_rndis.ko with usb_f_rndis.ko 2013-12-12 13:43:38 -06:00
u_serial.c
u_serial.h
u_uac1.c usb: gadget: u_uac1: add __user annotation 2013-08-09 16:34:13 +03:00
u_uac1.h
udc-core.c usb: gadget: udc-core: Do not report -EISNAM error from gadgetfs 2013-10-04 09:44:43 -05:00
usbstring.c usb: delete non-required instances of include <linux/init.h> 2014-01-08 15:01:39 -08:00
uvc_queue.c usb: gadget: uvc: Fix error handling in uvc_queue_buffer() 2013-08-09 17:40:54 +03:00
uvc_queue.h
uvc_v4l2.c
uvc_video.c
uvc.h [media] f_uvc: add v4l2_device and replace parent with v4l2_dev 2013-06-21 11:04:47 -03:00
webcam.c
zero.c Linux 3.13-rc4 2013-12-19 09:18:53 -06:00