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usbnet: introduce usbnet_{read|write}_cmd_nopm 

This patch introduces the below two helpers to prepare for solving
the usbnet runtime PM problem, which may cause some network utilities
(ifconfig, ethtool,...) touch a suspended device.

	usbnet_read_cmd_nopm()
	usbnet_write_cmd_nopm()

The above two helpers should be called by usbnet resume/suspend
callback to avoid deadlock.

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ming Lei 2012-11-06 04:53:04 +00:00 committed by David S. Miller
parent ef468d2347
commit 0547fad2dd
2 changed files with 61 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

62
drivers/net/usb/usbnet.c
View File

@ -1611,8 +1611,8 @@ void usbnet_device_suggests_idle(struct usbnet *dev)
EXPORT_SYMBOL(usbnet_device_suggests_idle);
/*-------------------------------------------------------------------------*/
int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
u16 value, u16 index, void *data, u16 size)
static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
u16 value, u16 index, void *data, u16 size)
{
void *buf = NULL;
int err = -ENOMEM;
@ -1636,10 +1636,10 @@ int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
out:
return err;
}
EXPORT_SYMBOL_GPL(usbnet_read_cmd);
int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
u16 value, u16 index, const void *data, u16 size)
static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
u16 value, u16 index, const void *data,
u16 size)
{
void *buf = NULL;
int err = -ENOMEM;
@ -1662,8 +1662,56 @@ int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
out:
return err;
}
/*
* The function can't be called inside suspend/resume callback,
* otherwise deadlock will be caused.
*/
int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
u16 value, u16 index, void *data, u16 size)
{
return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
data, size);
}
EXPORT_SYMBOL_GPL(usbnet_read_cmd);
/*
* The function can't be called inside suspend/resume callback,
* otherwise deadlock will be caused.
*/
int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
u16 value, u16 index, const void *data, u16 size)
{
return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
data, size);
}
EXPORT_SYMBOL_GPL(usbnet_write_cmd);
/*
* The function can be called inside suspend/resume callback safely
* and should only be called by suspend/resume callback generally.
*/
int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
u16 value, u16 index, void *data, u16 size)
{
return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
data, size);
}
EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
/*
* The function can be called inside suspend/resume callback safely
* and should only be called by suspend/resume callback generally.
*/
int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
u16 value, u16 index, const void *data,
u16 size)
{
return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
data, size);
}
EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
static void usbnet_async_cmd_cb(struct urb *urb)
{
struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
@ -1677,6 +1725,10 @@ static void usbnet_async_cmd_cb(struct urb *urb)
usb_free_urb(urb);
}
/*
* The caller must make sure that device can't be put into suspend
* state until the control URB completes.
*/
int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
u16 value, u16 index, const void *data, u16 size)
{

4
include/linux/usb/usbnet.h
View File

@ -167,6 +167,10 @@ extern int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
u16 value, u16 index, void *data, u16 size);
extern int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
u16 value, u16 index, const void *data, u16 size);
extern int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
u16 value, u16 index, void *data, u16 size);
extern int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
u16 value, u16 index, const void *data, u16 size);
extern int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
u16 value, u16 index, const void *data, u16 size);