From: Christoph Hellwig <hch@infradead.org>
To: David Miller <davem@davemloft.net>
Cc: brian.brooks@linaro.org, antoine.tenart@bootlin.com,
maxime.chevallier@bootlin.com, ymarkman@marvell.com,
stefanc@marvell.com, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, bjorn.topel@intel.com,
brian.brooks@arm.com
Subject: Re: [PATCH] net: mvpp2: avoid bouncing buffers
Date: Sun, 19 Aug 2018 23:23:26 -0700 [thread overview]
Message-ID: <20180820062326.GA22222@infradead.org> (raw)
In-Reply-To: <20180819.195505.1988137313680465320.davem@davemloft.net>
On Sun, Aug 19, 2018 at 07:55:05PM -0700, David Miller wrote:
> From: Brian Brooks <brian.brooks@linaro.org>
> Date: Sun, 19 Aug 2018 21:47:30 -0500
>
> > @@ -5126,6 +5126,12 @@ static int mvpp2_probe(struct platform_device *pdev)
> > }
> >
> > if (priv->hw_version == MVPP22) {
> > + /* Platform code may have set dev->dma_mask to point
> > + * to dev->coherent_dma_mask, but we want to ensure
> > + * they take different values due to comment below.
> > + */
> > + pdev->dev.dma_mask = &priv->dma_mask;
>
> The platform code might be doing this exactly because it cannot support
> different coherent and streaming DMA masks.
>
> Well, in any case, the platform code is doing it for a reason and
> overriding this in a "driver" of all places seems totally
> inappropriate and at best a layering violation.
>
> I would rather you fix this in a way that involves well defined APIs
> that set the DMA masks or whatever to the values that you need, rather
> than going behind the platform code's back and changing the DMA mask
> pointer like this.
Agreed. What platform do you see this issue on?
next prev parent reply other threads:[~2018-08-20 6:23 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-20 2:47 [PATCH] net: mvpp2: avoid bouncing buffers Brian Brooks
2018-08-20 2:55 ` David Miller
2018-08-20 6:23 ` Christoph Hellwig [this message]
2018-08-20 7:02 ` Yan Markman
2018-08-27 13:55 ` Brian Brooks
2018-08-27 15:48 ` Christoph Hellwig
2018-08-27 15:48 ` Christoph Hellwig
2018-09-02 2:10 ` Brian Brooks
2019-03-01 14:26 ` Antoine Tenart
2019-03-11 15:46 ` Christoph Hellwig
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180820062326.GA22222@infradead.org \
--to=hch@infradead.org \
--cc=antoine.tenart@bootlin.com \
--cc=bjorn.topel@intel.com \
--cc=brian.brooks@arm.com \
--cc=brian.brooks@linaro.org \
--cc=davem@davemloft.net \
--cc=linux-kernel@vger.kernel.org \
--cc=maxime.chevallier@bootlin.com \
--cc=netdev@vger.kernel.org \
--cc=stefanc@marvell.com \
--cc=ymarkman@marvell.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.