[PATCH 01/12] usbnet: introduce usbnet 3 command helpers

Subsystems: networking drivers, the rest, usb "usbnet" driver framework, usb networking drivers, usb subsystem

STALE5118d

4 messages, 3 authors, 2012-10-10 · open the first message on its own page

[PATCH 01/12] usbnet: introduce usbnet 3 command helpers

From: Ming Lei <hidden>
Date: 2012-10-02 06:51:12

This patch introduces the below 3 usb command helpers:

	usbnet_read_cmd / usbnet_write_cmd / usbnet_write_cmd_async

so that each low level driver doesn't need to implement them
by itself, and the dma buffer allocation for usb transfer and
runtime PM things can be handled just in one place.

Signed-off-by: Ming Lei <redacted>
---
 drivers/net/usb/usbnet.c   |  133 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/usb/usbnet.h |    6 ++
 2 files changed, 139 insertions(+)
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index fc9f578..3b51554 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -1592,6 +1592,139 @@ int usbnet_resume (struct usb_interface *intf)
 }
 EXPORT_SYMBOL_GPL(usbnet_resume);
 
+/*-------------------------------------------------------------------------*/
+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;
+
+	netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
+		   " value=0x%04x index=0x%04x size=%d\n",
+		   cmd, reqtype, value, index, size);
+
+	if (data) {
+		buf = kmalloc(size, GFP_KERNEL);
+		if (!buf)
+			goto out;
+	}
+
+	err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
+			      cmd, reqtype, value, index, buf, size,
+			      USB_CTRL_GET_TIMEOUT);
+	if (err > 0 && err <= size)
+		memcpy(data, buf, err);
+	kfree(buf);
+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)
+{
+	void *buf = NULL;
+	int err = -ENOMEM;
+
+	netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
+		   " value=0x%04x index=0x%04x size=%d\n",
+		   cmd, reqtype, value, index, size);
+
+	if (data) {
+		buf = kmemdup(data, size, GFP_KERNEL);
+		if (!buf)
+			goto out;
+	}
+
+	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
+			      cmd, reqtype, value, index, buf, size,
+			      USB_CTRL_SET_TIMEOUT);
+	kfree(buf);
+
+out:
+	return err;
+}
+EXPORT_SYMBOL_GPL(usbnet_write_cmd);
+
+static void usbnet_async_cmd_cb(struct urb *urb)
+{
+	struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
+	int status = urb->status;
+
+	if (status < 0)
+		dev_dbg(&urb->dev->dev, "%s failed with %d",
+			__func__, status);
+
+	kfree(req);
+	usb_free_urb(urb);
+}
+
+int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
+			   u16 value, u16 index, const void *data, u16 size)
+{
+	struct usb_ctrlrequest *req = NULL;
+	struct urb *urb;
+	int err = -ENOMEM;
+	void *buf = NULL;
+
+	netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
+		   " value=0x%04x index=0x%04x size=%d\n",
+		   cmd, reqtype, value, index, size);
+
+	urb = usb_alloc_urb(0, GFP_ATOMIC);
+	if (!urb) {
+		netdev_err(dev->net, "Error allocating URB in"
+			   " %s!\n", __func__);
+		goto fail;
+	}
+
+	if (data) {
+		buf = kmemdup(data, size, GFP_ATOMIC);
+		if (!buf) {
+			netdev_err(dev->net, "Error allocating buffer"
+				   " in %s!\n", __func__);
+			goto fail_free;
+		}
+	}
+
+	req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
+	if (!req) {
+		netdev_err(dev->net, "Failed to allocate memory for %s\n",
+			   __func__);
+		goto fail_free_buf;
+	}
+
+	req->bRequestType = reqtype;
+	req->bRequest = cmd;
+	req->wValue = cpu_to_le16(value);
+	req->wIndex = cpu_to_le16(index);
+	req->wLength = cpu_to_le16(size);
+
+	usb_fill_control_urb(urb, dev->udev,
+			     usb_sndctrlpipe(dev->udev, 0),
+			     (void *)req, buf, size,
+			     usbnet_async_cmd_cb, req);
+	urb->transfer_flags |= URB_FREE_BUFFER;
+
+	err = usb_submit_urb(urb, GFP_ATOMIC);
+	if (err < 0) {
+		netdev_err(dev->net, "Error submitting the control"
+			   " message: status=%d\n", err);
+		goto fail_free;
+	}
+	return 0;
+
+fail_free_buf:
+	kfree(buf);
+fail_free:
+	kfree(req);
+	usb_free_urb(urb);
+fail:
+	return err;
+
+}
+EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
+
 
 /*-------------------------------------------------------------------------*/
 
diff --git a/include/linux/usb/usbnet.h b/include/linux/usb/usbnet.h
index f87cf62..32a57dd 100644
--- a/include/linux/usb/usbnet.h
+++ b/include/linux/usb/usbnet.h
@@ -161,6 +161,12 @@ extern int usbnet_suspend(struct usb_interface *, pm_message_t);
 extern int usbnet_resume(struct usb_interface *);
 extern void usbnet_disconnect(struct usb_interface *);
 
+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_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
+		    u16 value, u16 index, const void *data, u16 size);
 
 /* Drivers that reuse some of the standard USB CDC infrastructure
  * (notably, using multiple interfaces according to the CDC
-- 
1.7.9.5

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Re: [PATCH 01/12] usbnet: introduce usbnet 3 command helpers

From: Oliver Neukum <hidden>
Date: 2012-10-09 08:48:46

On Tuesday 02 October 2012 14:51:12 Ming Lei wrote:
quoted hunk
This patch introduces the below 3 usb command helpers:

	usbnet_read_cmd / usbnet_write_cmd / usbnet_write_cmd_async

so that each low level driver doesn't need to implement them
by itself, and the dma buffer allocation for usb transfer and
runtime PM things can be handled just in one place.

Signed-off-by: Ming Lei <redacted>
---
 drivers/net/usb/usbnet.c   |  133 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/usb/usbnet.h |    6 ++
 2 files changed, 139 insertions(+)
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index fc9f578..3b51554 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -1592,6 +1592,139 @@ int usbnet_resume (struct usb_interface *intf)
 }
 EXPORT_SYMBOL_GPL(usbnet_resume);
 
+/*-------------------------------------------------------------------------*/
+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;
+
+	netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
+		   " value=0x%04x index=0x%04x size=%d\n",
+		   cmd, reqtype, value, index, size);
+
+	if (data) {
+		buf = kmalloc(size, GFP_KERNEL);
Using GFP_KERNEL you preclude using those in resume() and error handling.
Please pass a gfp_t parameter.

	Regards
		Oliver

Re: [PATCH 01/12] usbnet: introduce usbnet 3 command helpers

From: Ming Lei <hidden>
Date: 2012-10-10 03:19:11

On Tue, Oct 9, 2012 at 4:47 PM, Oliver Neukum [off-list ref] wrote:
Using GFP_KERNEL you preclude using those in resume() and error handling.
Please pass a gfp_t parameter.
IMO, it is not a big deal because generally only several bytes are to be
allocated inside these helpers.

If you still think the problem should be considered, another candidate fix
is to take GFP_NOIO during system suspend/resume, and take GFP_KERNEL
in other situations.

Thanks,
--
Ming Lei

Re: [PATCH 01/12] usbnet: introduce usbnet 3 command helpers

From: Ming Lei <hidden>
Date: 2012-10-10 05:56:18

On Wed, Oct 10, 2012 at 11:19 AM, Ming Lei [off-list ref] wrote:
On Tue, Oct 9, 2012 at 4:47 PM, Oliver Neukum [off-list ref] wrote:
quoted
Using GFP_KERNEL you preclude using those in resume() and error handling.
Please pass a gfp_t parameter.
IMO, it is not a big deal because generally only several bytes are to be
allocated inside these helpers.
Also pm_restrict_gfp_mask()/pm_restore_gfp_mask() have been introduced
to address the problem for 2 years, looks the gfp_t isn't needed, doesn't it?

Thanks,
--
Ming Lei
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