From: Andrew Morton <akpm@linux-foundation.org>
To: Alexander Holler <holler@ahsoftware.de>
Cc: linux-kernel@vger.kernel.org, linux-fbdev@vger.kernel.org,
Florian Tobias Schandinat <FlorianSchandinat@gmx.de>,
Bernie Thompson <bernie@plugable.com>,
Steve Glendinning <steve.glendinning@shawell.net>,
stable@vger.kernel.org
Subject: Re: [PATCH 2/3 v2] fb: udlfb: fix hang at disconnect
Date: Tue, 29 Jan 2013 00:22:38 +0000 [thread overview]
Message-ID: <20130128162238.7fba92fe.akpm@linux-foundation.org> (raw)
In-Reply-To: <1359139768-32294-2-git-send-email-holler@ahsoftware.de>
On Fri, 25 Jan 2013 19:49:27 +0100
Alexander Holler <holler@ahsoftware.de> wrote:
> When a device was disconnected the driver may hang at waiting for urbs it never
> will get. Fix this by using a timeout while waiting for the used semaphore.
>
> There is still a memory leak if a timeout happens, but at least the driver
> now continues his disconnect routine.
>
> ...
>
> --- a/drivers/video/udlfb.c
> +++ b/drivers/video/udlfb.c
> @@ -1832,8 +1832,9 @@ static void dlfb_free_urb_list(struct dlfb_data *dev)
> /* keep waiting and freeing, until we've got 'em all */
> while (count--) {
>
> - /* Getting interrupted means a leak, but ok at disconnect */
> - ret = down_interruptible(&dev->urbs.limit_sem);
> + /* Timeout likely occurs at disconnect (resulting in a leak) */
> + ret = down_timeout_killable(&dev->urbs.limit_sem,
> + FREE_URB_TIMEOUT);
> if (ret)
> break;
This is rather a hack. Do you have an understanding of the underlying
bug? Why is the driver waiting for things which will never happen?
WARNING: multiple messages have this Message-ID (diff)
From: Andrew Morton <akpm@linux-foundation.org>
To: Alexander Holler <holler@ahsoftware.de>
Cc: linux-kernel@vger.kernel.org, linux-fbdev@vger.kernel.org,
Florian Tobias Schandinat <FlorianSchandinat@gmx.de>,
Bernie Thompson <bernie@plugable.com>,
Steve Glendinning <steve.glendinning@shawell.net>,
<stable@vger.kernel.org>
Subject: Re: [PATCH 2/3 v2] fb: udlfb: fix hang at disconnect
Date: Mon, 28 Jan 2013 16:22:38 -0800 [thread overview]
Message-ID: <20130128162238.7fba92fe.akpm@linux-foundation.org> (raw)
In-Reply-To: <1359139768-32294-2-git-send-email-holler@ahsoftware.de>
On Fri, 25 Jan 2013 19:49:27 +0100
Alexander Holler <holler@ahsoftware.de> wrote:
> When a device was disconnected the driver may hang at waiting for urbs it never
> will get. Fix this by using a timeout while waiting for the used semaphore.
>
> There is still a memory leak if a timeout happens, but at least the driver
> now continues his disconnect routine.
>
> ...
>
> --- a/drivers/video/udlfb.c
> +++ b/drivers/video/udlfb.c
> @@ -1832,8 +1832,9 @@ static void dlfb_free_urb_list(struct dlfb_data *dev)
> /* keep waiting and freeing, until we've got 'em all */
> while (count--) {
>
> - /* Getting interrupted means a leak, but ok at disconnect */
> - ret = down_interruptible(&dev->urbs.limit_sem);
> + /* Timeout likely occurs at disconnect (resulting in a leak) */
> + ret = down_timeout_killable(&dev->urbs.limit_sem,
> + FREE_URB_TIMEOUT);
> if (ret)
> break;
This is rather a hack. Do you have an understanding of the underlying
bug? Why is the driver waiting for things which will never happen?
next prev parent reply other threads:[~2013-01-29 0:22 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-12 13:20 [PATCH] fb: udlfb: fix hang at disconnect Alexander Holler
2013-01-12 13:20 ` Alexander Holler
2013-01-12 22:22 ` Bernie Thompson
2013-01-12 22:22 ` Bernie Thompson
2013-01-13 12:05 ` Alexander Holler
2013-01-13 12:05 ` Alexander Holler
2013-01-13 12:24 ` Alexander Holler
2013-01-13 12:24 ` Alexander Holler
2013-01-25 18:49 ` [PATCH 1/3] semaphore: introduce down_timeout_killable() Alexander Holler
2013-01-25 18:49 ` Alexander Holler
2013-01-25 18:49 ` [PATCH 2/3 v2] fb: udlfb: fix hang at disconnect Alexander Holler
2013-01-25 18:49 ` Alexander Holler
2013-01-29 0:22 ` Andrew Morton [this message]
2013-01-29 0:22 ` Andrew Morton
2013-01-29 0:56 ` Alexander Holler
2013-01-29 0:56 ` Alexander Holler
2013-01-29 10:35 ` Alexander Holler
2013-01-29 10:35 ` Alexander Holler
2013-01-29 11:11 ` Alexander Holler
2013-01-29 11:11 ` Alexander Holler
2013-01-29 15:51 ` Alexander Holler
2013-01-29 15:51 ` Alexander Holler
2013-01-29 20:35 ` Alexander Holler
2013-01-29 20:35 ` Alexander Holler
2013-01-29 20:56 ` Alexander Holler
2013-01-29 20:56 ` Alexander Holler
2013-02-04 1:14 ` Greg KH
2013-02-04 1:14 ` Greg KH
2013-02-04 12:05 ` Alexander Holler
2013-02-04 12:05 ` Alexander Holler
2013-02-04 19:17 ` Alexander Holler
2013-02-04 19:17 ` Alexander Holler
2013-02-04 19:25 ` Greg KH
2013-02-04 19:25 ` Greg KH
2013-02-05 7:08 ` Alexander Holler
2013-02-05 7:08 ` Alexander Holler
2013-02-05 17:22 ` Greg KH
2013-02-05 17:22 ` Greg KH
2013-02-05 17:36 ` Alexander Holler
2013-02-05 17:36 ` Alexander Holler
2013-02-08 4:07 ` Dave Airlie
2013-02-08 4:07 ` Dave Airlie
2013-02-08 9:53 ` Alexander Holler
2013-02-08 9:53 ` Alexander Holler
2013-01-25 18:49 ` [PATCH 3/3] fb: smscufx: " Alexander Holler
2013-01-25 18:49 ` Alexander Holler
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