From: Daniel Mack <zonque@gmail•com>
To: David Miller <davem@davemloft•net>, julia.lawall@lip6•fr
Cc: netdev@vger•kernel.org
Subject: Re: question about drivers/net/ethernet/ti/cpsw.c
Date: Tue, 02 Sep 2014 11:34:16 +0200 [thread overview]
Message-ID: <54058F18.8060709@gmail.com> (raw)
In-Reply-To: <20140901.181101.2132157946809255487.davem@davemloft.net>
On 09/02/2014 03:11 AM, David Miller wrote:
> From: Julia Lawall <julia.lawall@lip6•fr>
> Date: Thu, 28 Aug 2014 21:26:55 +0200 (CEST)
>
>> I wonder if the following patch:
>>
>> commit aa1a15e2d9199711cdcc9399fdb22544ab835a83
>> Author: Daniel Mack <zonque@gmail•com>
>> Date: Sat Sep 21 00:50:38 2013 +0530
>>
>> introduced a race condition in drivers/net/ethernet/ti/cpsw.c. I was
>> looking at an old version of the file (Linux 3.10), and it has
>>
>> clean_irq_ret:
>> for (i = 0; i < priv->num_irqs; i++)
>> free_irq(priv->irqs_table[i], priv);
>>
>> at the beginning of the cleanup code of the probe function (cpsw_probe).
>> The above patch replaces request_irq by devm_request_irq and gets rid of
>> the above cleanup code. But that moves the stopping of the interrupts
>> after the following code at the end of the function:
>>
>> free_netdev(priv->ndev);
>>
>> The interrupt handler (cpsw_interrupt) does reference priv->ndev:
>>
>> if (netif_running(priv->ndev)) {
>> napi_schedule(&priv->napi);
>> return IRQ_HANDLED;
>> }
>>
>> so perhaps this could be a problem. The same happens in the remove
>> function.
>
> It could definitely be a problem.
>
> Probably it would be better for this device to request IRQs in open
> and release them in close like so many other networking drivers do.
Thanks for spotting this, Julia!
I'll be working on a fix for this as soon as I can.
Best regards,
Daniel
next prev parent reply other threads:[~2014-09-02 9:34 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-28 19:26 question about drivers/net/ethernet/ti/cpsw.c Julia Lawall
2014-09-02 1:11 ` David Miller
2014-09-02 9:34 ` Daniel Mack [this message]
2014-09-02 16:34 ` Daniel Mack
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