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Kirill Smelkov
linux
Commits
9f17d516
Commit
9f17d516
authored
Aug 04, 2010
by
Jiri Kosina
Browse files
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Merge branch 'bkl' into for-linus
parents
ada8c797
bd25f4dd
Changes
1
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1 changed file
with
12 additions
and
42 deletions
+12
-42
drivers/hid/usbhid/hiddev.c
drivers/hid/usbhid/hiddev.c
+12
-42
No files found.
drivers/hid/usbhid/hiddev.c
View file @
9f17d516
...
...
@@ -67,7 +67,7 @@ struct hiddev_list {
struct
mutex
thread_lock
;
};
static
struct
hiddev
*
hiddev_table
[
HIDDEV_MINORS
]
;
static
struct
usb_driver
hiddev_driver
;
/*
* Find a report, given the report's type and ID. The ID can be specified
...
...
@@ -265,22 +265,19 @@ static int hiddev_release(struct inode * inode, struct file * file)
static
int
hiddev_open
(
struct
inode
*
inode
,
struct
file
*
file
)
{
struct
hiddev_list
*
list
;
int
res
,
i
;
/* See comment in hiddev_connect() for BKL explanation */
lock_kernel
();
i
=
iminor
(
inode
)
-
HIDDEV_MINOR_BASE
;
struct
usb_interface
*
intf
;
struct
hiddev
*
hiddev
;
int
res
;
if
(
i
>=
HIDDEV_MINORS
||
i
<
0
||
!
hiddev_table
[
i
])
intf
=
usb_find_interface
(
&
hiddev_driver
,
iminor
(
inode
));
if
(
!
intf
)
return
-
ENODEV
;
hiddev
=
usb_get_intfdata
(
intf
);
if
(
!
(
list
=
kzalloc
(
sizeof
(
struct
hiddev_list
),
GFP_KERNEL
)))
return
-
ENOMEM
;
mutex_init
(
&
list
->
thread_lock
);
list
->
hiddev
=
hiddev_table
[
i
];
list
->
hiddev
=
hiddev
;
file
->
private_data
=
list
;
/*
...
...
@@ -289,7 +286,7 @@ static int hiddev_open(struct inode *inode, struct file *file)
*/
if
(
list
->
hiddev
->
exist
)
{
if
(
!
list
->
hiddev
->
open
++
)
{
res
=
usbhid_open
(
hiddev
_table
[
i
]
->
hid
);
res
=
usbhid_open
(
hiddev
->
hid
);
if
(
res
<
0
)
{
res
=
-
EIO
;
goto
bail
;
...
...
@@ -301,12 +298,12 @@ static int hiddev_open(struct inode *inode, struct file *file)
}
spin_lock_irq
(
&
list
->
hiddev
->
list_lock
);
list_add_tail
(
&
list
->
node
,
&
hiddev
_table
[
i
]
->
list
);
list_add_tail
(
&
list
->
node
,
&
hiddev
->
list
);
spin_unlock_irq
(
&
list
->
hiddev
->
list_lock
);
if
(
!
list
->
hiddev
->
open
++
)
if
(
list
->
hiddev
->
exist
)
{
struct
hid_device
*
hid
=
hiddev
_table
[
i
]
->
hid
;
struct
hid_device
*
hid
=
hiddev
->
hid
;
res
=
usbhid_get_power
(
hid
);
if
(
res
<
0
)
{
res
=
-
EIO
;
...
...
@@ -314,13 +311,10 @@ static int hiddev_open(struct inode *inode, struct file *file)
}
usbhid_open
(
hid
);
}
unlock_kernel
();
return
0
;
bail:
file
->
private_data
=
NULL
;
kfree
(
list
);
unlock_kernel
();
return
res
;
}
...
...
@@ -894,37 +888,14 @@ int hiddev_connect(struct hid_device *hid, unsigned int force)
hid
->
hiddev
=
hiddev
;
hiddev
->
hid
=
hid
;
hiddev
->
exist
=
1
;
/*
* BKL here is used to avoid race after usb_register_dev().
* Once the device node has been created, open() could happen on it.
* The code below will then fail, as hiddev_table hasn't been
* updated.
*
* The obvious fix -- introducing mutex to guard hiddev_table[]
* doesn't work, as usb_open() and usb_register_dev() both take
* minor_rwsem, thus we'll have ABBA deadlock.
*
* Before BKL pushdown, usb_open() had been acquiring it in right
* order, so _open() was safe to use it to protect from this race.
* Now the order is different, but AB-BA deadlock still doesn't occur
* as BKL is dropped on schedule() (i.e. while sleeping on
* minor_rwsem). Fugly.
*/
lock_kernel
();
usb_set_intfdata
(
usbhid
->
intf
,
usbhid
);
retval
=
usb_register_dev
(
usbhid
->
intf
,
&
hiddev_class
);
if
(
retval
)
{
err_hid
(
"Not able to get a minor for this device."
);
hid
->
hiddev
=
NULL
;
unlock_kernel
();
kfree
(
hiddev
);
return
-
1
;
}
else
{
hid
->
minor
=
usbhid
->
intf
->
minor
;
hiddev_table
[
usbhid
->
intf
->
minor
-
HIDDEV_MINOR_BASE
]
=
hiddev
;
}
unlock_kernel
();
return
0
;
}
...
...
@@ -942,7 +913,6 @@ void hiddev_disconnect(struct hid_device *hid)
hiddev
->
exist
=
0
;
mutex_unlock
(
&
hiddev
->
existancelock
);
hiddev_table
[
hiddev
->
hid
->
minor
-
HIDDEV_MINOR_BASE
]
=
NULL
;
usb_deregister_dev
(
usbhid
->
intf
,
&
hiddev_class
);
if
(
hiddev
->
open
)
{
...
...
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