diff options
| author | Sudeep Holla <sudeep.holla@arm.com> | 2015-03-04 20:07:57 +0300 |
|---|---|---|
| committer | Felipe Balbi <balbi@ti.com> | 2015-03-09 18:44:08 +0300 |
| commit | 798523973dcc93c2440932dc4dfe76fbf571f668 (patch) | |
| tree | 8176084ab1ca1c9864960c97159e1c523d5a0766 /drivers/usb/isp1760 | |
| parent | 9eccca0843205f87c00404b663188b88eb248051 (diff) | |
| download | linux-798523973dcc93c2440932dc4dfe76fbf571f668.tar.xz | |
usb: isp1760: fix possible deadlock in isp1760_udc_irq
Use spin_{un,}lock_irq{save,restore} in isp1760_udc_{start,stop} to
prevent following potentially deadlock scenario between
isp1760_udc_{start,stop} and isp1760_udc_irq :
=================================
[ INFO: inconsistent lock state ]
4.0.0-rc2-00004-gf7bb2ef60173 #51 Not tainted
---------------------------------
inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
in:imklog/2118 [HC1[1]:SC0[0]:HE0:SE1] takes:
(&(&udc->lock)->rlock){?.+...}, at: [<c0397a93>] isp1760_udc_irq+0x367/0x9dc
{HARDIRQ-ON-W} state was registered at:
[<c05135b3>] _raw_spin_lock+0x23/0x30
[<c0396b87>] isp1760_udc_start+0x23/0xf8
[<c039dc21>] udc_bind_to_driver+0x71/0xb0
[<c039de4f>] usb_gadget_probe_driver+0x53/0x9c
[<bf80d0df>] usb_composite_probe+0x8a/0xa4 [libcomposite]
[<bf8311a7>] 0xbf8311a7
[<c00088c5>] do_one_initcall+0x8d/0x17c
[<c050b92d>] do_init_module+0x49/0x148
[<c0087323>] load_module+0xb7f/0xbc4
[<c0087471>] SyS_finit_module+0x51/0x74
[<c000d8c1>] ret_fast_syscall+0x1/0x68
irq event stamp: 4966
hardirqs last enabled at (4965): [<c05137df>] _raw_spin_unlock_irq+0x1f/0x24
hardirqs last disabled at (4966): [<c00110b3>] __irq_svc+0x33/0x64
softirqs last enabled at (4458): [<c0023475>] __do_softirq+0x23d/0x2d0
softirqs last disabled at (4389): [<c002380b>] irq_exit+0xef/0x15c
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&(&udc->lock)->rlock);
<Interrupt>
lock(&(&udc->lock)->rlock);
*** DEADLOCK ***
1 lock held by in:imklog/2118:
#0: (&f->f_pos_lock){+.+.+.}, at: [<c010a101>] __fdget_pos+0x31/0x34
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Diffstat (limited to 'drivers/usb/isp1760')
| -rw-r--r-- | drivers/usb/isp1760/isp1760-udc.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/usb/isp1760/isp1760-udc.c b/drivers/usb/isp1760/isp1760-udc.c index 9612d7990565..19e6a172ff82 100644 --- a/drivers/usb/isp1760/isp1760-udc.c +++ b/drivers/usb/isp1760/isp1760-udc.c @@ -1191,6 +1191,7 @@ static int isp1760_udc_start(struct usb_gadget *gadget, struct usb_gadget_driver *driver) { struct isp1760_udc *udc = gadget_to_udc(gadget); + unsigned long flags; /* The hardware doesn't support low speed. */ if (driver->max_speed < USB_SPEED_FULL) { @@ -1198,7 +1199,7 @@ static int isp1760_udc_start(struct usb_gadget *gadget, return -EINVAL; } - spin_lock(&udc->lock); + spin_lock_irqsave(&udc->lock, flags); if (udc->driver) { dev_err(udc->isp->dev, "UDC already has a gadget driver\n"); @@ -1208,7 +1209,7 @@ static int isp1760_udc_start(struct usb_gadget *gadget, udc->driver = driver; - spin_unlock(&udc->lock); + spin_unlock_irqrestore(&udc->lock, flags); dev_dbg(udc->isp->dev, "starting UDC with driver %s\n", driver->function); @@ -1232,6 +1233,7 @@ static int isp1760_udc_start(struct usb_gadget *gadget, static int isp1760_udc_stop(struct usb_gadget *gadget) { struct isp1760_udc *udc = gadget_to_udc(gadget); + unsigned long flags; dev_dbg(udc->isp->dev, "%s\n", __func__); @@ -1239,9 +1241,9 @@ static int isp1760_udc_stop(struct usb_gadget *gadget) isp1760_udc_write(udc, DC_MODE, 0); - spin_lock(&udc->lock); + spin_lock_irqsave(&udc->lock, flags); udc->driver = NULL; - spin_unlock(&udc->lock); + spin_unlock_irqrestore(&udc->lock, flags); return 0; } |