linux-kernel - Re: [PATCH v2 1/6] serial: imx: only set DMA rx-ing when DMA starts

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <49bfa666-b036-3ed9-8209-9ea59468371b@collabora.com>
Date:   Thu, 6 Jul 2017 10:31:38 +0200
From:   Romain Perier <romain.perier@...labora.com>
To:     Uwe Kleine-König <u.kleine-koenig@...gutronix.de>
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        linux-serial@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org, Nandor Han <nandor.han@...com>
Subject: Re: [PATCH v2 1/6] serial: imx: only set DMA rx-ing when DMA starts

Hello,


Le 05/07/2017 à 15:29, Uwe Kleine-König a écrit :
> Hello,
>
> On Wed, Jul 05, 2017 at 03:07:01PM +0200, Romain Perier wrote:
>> From: Nandor Han <nandor.han@...com>
>>
>> Avoid the situation when `dma_is_rxing` could incorrectly signal that
>> DMA RX channel is receiving data in case DMA preparation or sg mapping
>> fails.
>>
>> This commit fixes the issues by moving the assignment of dma_is_rxing
>> out of imx_disable_rx_int(), then the variable is set to 1 from
>> start_rx_dma() only when the preparation is correctly done.
> I'd write:
>
> 	There are a few issues with setting dma_is_rxing to 1 in
> 	imx_disable_rx_int:
>
> 	 - Currently always after imx_disable_rx_int() the function
> 	   start_rx_dma() is called. This dependency isn't obvious though.
> 	 - start_rx_dma() does error checking and might exit without enabling
> 	   DMA but keeping dma_is_rxing 1.
>
> 	So the more natural place for setting dma_is_rxing to 1 is in
> 	start_rx_dma after all errors are checked.
>
> If you use this, there is nothing left of Nandor Han's patch and you can
> drop his authorship.
>
> Best regards
> Uwe
>
Ok, will do. No other feedback for the rest of the series ? (just to
know if I send a v3 or If I wait a bit...)

Thanks,
Romain