linux-kernel - Re: [PATCH 4/4] mmc: sdhci-esdhc-imx: Remove the ENGcm07207 workaround

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]

Date:   Mon, 29 May 2017 16:42:23 +0200
From:   Ulf Hansson <ulf.hansson@...aro.org>
To:     Adrian Hunter <adrian.hunter@...el.com>
Cc:     Benoît Thébaudeau <benoit@...stem.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-mmc@...r.kernel.org" <linux-mmc@...r.kernel.org>,
        Fabio Estevam <fabio.estevam@....com>,
        joancarles <joancarles@...ngenieria.es>,
        Eric Bénard <eric@...rea.com>,
        Wolfram Sang <wsa@...-dreams.de>
Subject: Re: [PATCH 4/4] mmc: sdhci-esdhc-imx: Remove the ENGcm07207 workaround

On 29 May 2017 at 10:07, Adrian Hunter <adrian.hunter@...el.com> wrote:
> On 03/05/17 13:05, Benoît Thébaudeau wrote:
>> The SDHCI_QUIRK_NO_MULTIBLOCK quirk was used as a workaround for the
>> ENGcm07207 erratum. However, it caused excruciatingly slow SD transfers
>> (300 kB/s on average), and this erratum actually does not imply that
>> multiple-block transfers are not supported, so this was overkill.
>>
>> The suggested workaround for this erratum is to set SYSCTL.RSTA, but the
>> simple DAT line software reset (which resets the DMA circuit among
>> others) triggered by sdhci_finish_data() in case of errors seems to be
>> sufficient. Indeed, generating errors in a controlled manner on i.MX25
>> using the FEVT register right in the middle of read data transfers
>> without this quirk shows that nothing is written to the buffer by the
>> eSDHC past CMD12, and no extra Auto CMD12 is sent with AC12EN set, so
>> the data transfers on AHB are properly aborted. For write data
>> transfers, neither extra data nor extra Auto CMD12 is sent, as expected.
>> Moreover, after intensive stress tests on i.MX25, removing
>> SDHCI_QUIRK_NO_MULTIBLOCK seems to be safe.
>>
>> Signed-off-by: Benoît Thébaudeau <benoit@...stem.com>
>
> Aside from one comment below...
>
> I would expect to see Acks from other sdhci-esdhc-imx users.  Nevertheless,
> for sdhci:

Yes, I would also appreciate some ack/tested by, from the
corresponding sdhci variant users of this series.

However, to allow it to get some results from linux-next, I have
queued up this series for next (amending $subject patch according to
the comment from Adrian). Thanks!

>
> Acked-by: Adrian Hunter <adrian.hunter@...el.com>
>
>

[...]

Kind regards
Uffe