From: Rupesh Gujare <rupesh.gujare@atmel.com>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: <devel@linuxdriverproject.org>, <gregkh@linuxfoundation.org>,
<linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/4] staging: ozwpan: Increment port number for new device.
Date: Mon, 5 Aug 2013 19:43:16 +0100 [thread overview]
Message-ID: <51FFF244.9000604@atmel.com> (raw)
In-Reply-To: <20130805175302.GJ5051@mwanda>
On 05/08/13 18:53, Dan Carpenter wrote:
> On Mon, Aug 05, 2013 at 06:40:13PM +0100, Rupesh Gujare wrote:
>> This patch fixes crash issue when there is quick cycle of
>> de-enumeration & enumeration due to loss of wireless link.
>>
>> It is found that sometimes new device (or coming back device)
>> returns very fast, even before USB core read out hub status,
>> resulting in allocation of same port, which results in unstable
>> system & crash.
>>
>> Above issue is resolved by making sure that we always assign
>> new port to new device, making sure that USB core reads correct
>> hub status.
>>
> This feels like papering over the problem. Surely the real fix
> would be to improve the reference counting.
>
> This patch is probably effective but it makes the code more subtle
> and it shows that we don't really understand what we are doing with
> regards to reference counting.
>
>
Probably this is easier way to fix issue, since we don't have reference
count for ports & we rely on flags to check port status.
Any suggestions are appreciated.
--
Regards,
Rupesh Gujare
next prev parent reply other threads:[~2013-08-05 18:43 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-05 17:40 [PATCH 0/4] staging: ozwpan: Fix crash issues Rupesh Gujare
2013-08-05 17:40 ` [PATCH 1/4] staging: ozwpan: Fixes crash due to invalid port aceess Rupesh Gujare
2013-08-05 18:20 ` Dan Carpenter
2013-08-05 17:40 ` [PATCH 2/4] staging: ozwpan: Increment port number for new device Rupesh Gujare
2013-08-05 17:53 ` Dan Carpenter
2013-08-05 18:43 ` Rupesh Gujare [this message]
2013-08-05 20:23 ` Dan Carpenter
2013-08-05 20:33 ` Dan Carpenter
2013-08-06 10:26 ` Rupesh Gujare
2013-08-06 10:41 ` Dan Carpenter
2013-08-12 21:57 ` Greg KH
2013-08-05 17:40 ` [PATCH 3/4] staging: ozwpan: Reset port configuration number Rupesh Gujare
2013-08-05 18:21 ` Dan Carpenter
2013-08-05 18:58 ` Rupesh Gujare
2013-08-05 17:40 ` [PATCH 4/4] staging: ozwpan: Return correct hub status Rupesh Gujare
2013-08-05 18:56 ` Dan Carpenter
2013-08-05 19:00 ` Rupesh Gujare
2013-08-05 19:28 ` Dan Carpenter
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