From mboxrd@z Thu Jan  1 00:00:00 1970
From: Lino Sanfilippo <lsanfil@marvell.com>
Subject: Re: [EXT] Re: [PATCH/RFC v2 net-next] ravb: unmap descriptors when
 freeing rings
Date: Thu, 12 Jan 2017 17:55:29 +0100
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Cc: David Miller <davem@davemloft.net>,
        Magnus Damm <magnus.damm@gmail.com>, <netdev@vger.kernel.org>,
        <linux-renesas-soc@vger.kernel.org>
To: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>,
        Simon Horman <horms@verge.net.au>
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Hi,

On 12.01.2017 17:37, Sergei Shtylyov wrote:
> External Email
>
> ----------------------------------------------------------------------
> On 01/12/2017 04:23 PM, Lino Sanfilippo wrote:
>
>>>>> +
>>>>> +    for (; priv->cur_tx[q] - priv->dirty_tx[q] > 0; priv->dirty_tx[q]++) {
>>
>> BTW: How can this work correctly when cur_tx wraps and dirty_tx is greater?
>
>    {cur|dirty}_tx never wrap.
>

Both values are 32 bit and AFAICS they are only incremented (and never reset or
decremented).
So what prevents them from wrapping every 2^32 processed tx descriptors? Am I missing
something?

Regards,
Lino