public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Axel Lin <axel.lin@gmail.com>
To: linux-kernel <linux-kernel@vger.kernel.org>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>,
	Oliver Neukum <oneukum@suse.de>,
	Marko Friedemann <mfr@bmx-chemnitz.de>,
	Christoph Fritz <chf.fritz@googlemail.com>,
	linux-input@vger.kernel.org
Subject: [PATCH] Input: xpad - ensure xpad->bulk_out is initialized before submitting urb
Date: Tue, 16 Nov 2010 10:15:31 +0800	[thread overview]
Message-ID: <1289873732.7485.4.camel@mola> (raw)

As pointed out by Oliver Neukum:
xpad->irq_in is currently submitted before xpad->bulk_out is allocated.
That however is a race, because the callback for irq_in can call
xpad360w_process_packet(), which will in turn submit the bulk URB.

This patch moves initialization for xpad->bulk_out earlier, so we can
ensure xpad->bulk_out is initialized before submitting urb.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
---
 drivers/input/joystick/xpad.c |   32 ++++++++++++++++----------------
 1 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/drivers/input/joystick/xpad.c b/drivers/input/joystick/xpad.c
index 4875de9..56abf3d 100644
--- a/drivers/input/joystick/xpad.c
+++ b/drivers/input/joystick/xpad.c
@@ -921,19 +921,7 @@ static int xpad_probe(struct usb_interface *intf, const struct usb_device_id *id
 
 	usb_set_intfdata(intf, xpad);
 
-	/*
-	 * Submit the int URB immediately rather than waiting for open
-	 * because we get status messages from the device whether
-	 * or not any controllers are attached.  In fact, it's
-	 * exactly the message that a controller has arrived that
-	 * we're waiting for.
-	 */
 	if (xpad->xtype == XTYPE_XBOX360W) {
-		xpad->irq_in->dev = xpad->udev;
-		error = usb_submit_urb(xpad->irq_in, GFP_KERNEL);
-		if (error)
-			goto fail7;
-
 		/*
 		 * Setup the message to set the LEDs on the
 		 * controller when it shows up
@@ -941,13 +929,13 @@ static int xpad_probe(struct usb_interface *intf, const struct usb_device_id *id
 		xpad->bulk_out = usb_alloc_urb(0, GFP_KERNEL);
 		if (!xpad->bulk_out) {
 			error = -ENOMEM;
-			goto fail8;
+			goto fail7;
 		}
 
 		xpad->bdata = kzalloc(XPAD_PKT_LEN, GFP_KERNEL);
 		if (!xpad->bdata) {
 			error = -ENOMEM;
-			goto fail9;
+			goto fail8;
 		}
 
 		xpad->bdata[2] = 0x08;
@@ -969,12 +957,24 @@ static int xpad_probe(struct usb_interface *intf, const struct usb_device_id *id
 		usb_fill_bulk_urb(xpad->bulk_out, udev,
 				usb_sndbulkpipe(udev, ep_irq_in->bEndpointAddress),
 				xpad->bdata, XPAD_PKT_LEN, xpad_bulk_out, xpad);
+
+		/*
+		 * Submit the int URB immediately rather than waiting for open
+		 * because we get status messages from the device whether
+		 * or not any controllers are attached.  In fact, it's
+		 * exactly the message that a controller has arrived that
+		 * we're waiting for.
+		 */
+		xpad->irq_in->dev = xpad->udev;
+		error = usb_submit_urb(xpad->irq_in, GFP_KERNEL);
+		if (error)
+			goto fail9;
 	}
 
 	return 0;
 
- fail9:	usb_free_urb(xpad->bulk_out);
- fail8:	usb_kill_urb(xpad->irq_in);
+ fail9:	kfree(xpad->bdata);
+ fail8:	usb_free_urb(xpad->bulk_out);
  fail7:	input_unregister_device(input_dev);
 	input_dev = NULL;
  fail6:	xpad_led_disconnect(xpad);
-- 
1.7.2




                 reply	other threads:[~2010-11-16  2:11 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1289873732.7485.4.camel@mola \
    --to=axel.lin@gmail.com \
    --cc=chf.fritz@googlemail.com \
    --cc=dmitry.torokhov@gmail.com \
    --cc=linux-input@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mfr@bmx-chemnitz.de \
    --cc=oneukum@suse.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox