linux-kernel - Re: [PATCH v2 2/2] iio: accel: Add driver support for ADXL355

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: <20210723184404.0000001d@Huawei.com>
Date:   Fri, 23 Jul 2021 18:44:04 +0100
From:   Jonathan Cameron <Jonathan.Cameron@...wei.com>
To:     Mark Brown <broonie@...nel.org>
CC:     Puranjay Mohan <puranjay12@...il.com>,
        <Michael.Hennerich@...log.com>, <alexandru.ardelean@...log.com>,
        <jic23@...nel.org>, <devicetree@...r.kernel.org>,
        <linux-iio@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <lars@...afoo.de>, <Dragos.Bogdan@...log.com>,
        <Darius.Berghe@...log.com>
Subject: Re: [PATCH v2 2/2] iio: accel: Add driver support for ADXL355

On Fri, 23 Jul 2021 18:14:22 +0100
Mark Brown <broonie@...nel.org> wrote:

> On Fri, Jul 23, 2021 at 06:10:22PM +0100, Jonathan Cameron wrote:
> 
> > @Mark.  This has come up a few times recently.  Are we now safe to assume
> > that regmap will always copy data when used with SPI and hence we no
> > longer need to ensure DMA safe buffers?     
> 
> Only for single register I/O, I'd not assume that for things like raw
> I/O.

Thanks for the confirmation.  So in this driver that means we
need DMA safe buffers for the regmap_bulk_ calls.  Easiest approach
is probably to use a __cacheline_aligned buffer at the end of the
iio_priv() structure.

> 
> Note that my name is spelt Mark.
> 

I'll blame Friday.

Thanks,

Jonathan