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authorMing Lei <ming.lei@canonical.com>2012-11-06 08:53:04 +0400
committerDavid S. Miller <davem@davemloft.net>2012-11-07 12:53:38 +0400
commit0547fad2dd7ccaaf3c914ba49073fa37e4e241eb (patch)
tree5434c18a01f9c4591c74e0bda596f1d4b29ddd6b /drivers/net/usb
parentef468d234753aff7afa96075d3be135b0df1ded0 (diff)
downloadlinux-0547fad2dd7ccaaf3c914ba49073fa37e4e241eb.tar.xz
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>
Diffstat (limited to 'drivers/net/usb')
-rw-r--r--drivers/net/usb/usbnet.c62
1 files changed, 57 insertions, 5 deletions
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 447d20d22b7c..0ac1ff3571cb 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -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)
{