From: Wolfram Sang <w.sang-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
To: Marek Vasut <marex-ynQEQJNshbs@public.gmane.org>
Cc: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
Fabio Estevam <festevam-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
Shawn Guo <shawn.guo-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>,
linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: possible MXS-i2c bug
Date: Fri, 27 Apr 2012 16:59:36 +0200 [thread overview]
Message-ID: <20120427145936.GD16504@pengutronix.de> (raw)
In-Reply-To: <201204270110.21377.marex-ynQEQJNshbs@public.gmane.org>
[-- Attachment #1: Type: text/plain, Size: 695 bytes --]
Hi,
> I've been thinking about the DMA approach. The problem I found out is that we
> need to transfer all messages we're given at time in one DMA chain ... at least
> that's how I understand it from the FSL manual (see Fig. 27-10 in the mx28
> manual).
I can't follow you: mxs_i2c_xfer() gets a list of messages, yet they
are iterated over in mxs_i2c_xfer_msg(). A single I2C message is
unscattered and can't be bigger than 64KB, so that should be doable?
Am I missing something by already being in weekend-mode? :)
--
Pengutronix e.K. | Wolfram Sang |
Industrial Linux Solutions | http://www.pengutronix.de/ |
[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 198 bytes --]
WARNING: multiple messages have this Message-ID (diff)
From: w.sang@pengutronix.de (Wolfram Sang)
To: linux-arm-kernel@lists.infradead.org
Subject: possible MXS-i2c bug
Date: Fri, 27 Apr 2012 16:59:36 +0200 [thread overview]
Message-ID: <20120427145936.GD16504@pengutronix.de> (raw)
In-Reply-To: <201204270110.21377.marex@denx.de>
Hi,
> I've been thinking about the DMA approach. The problem I found out is that we
> need to transfer all messages we're given at time in one DMA chain ... at least
> that's how I understand it from the FSL manual (see Fig. 27-10 in the mx28
> manual).
I can't follow you: mxs_i2c_xfer() gets a list of messages, yet they
are iterated over in mxs_i2c_xfer_msg(). A single I2C message is
unscattered and can't be bigger than 64KB, so that should be doable?
Am I missing something by already being in weekend-mode? :)
--
Pengutronix e.K. | Wolfram Sang |
Industrial Linux Solutions | http://www.pengutronix.de/ |
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 198 bytes
Desc: Digital signature
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20120427/115b71e8/attachment.sig>
next prev parent reply other threads:[~2012-04-27 14:59 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-26 11:26 possible MXS-i2c bug Marek Vasut
2012-04-26 11:41 ` Fabio Estevam
[not found] ` <201204261326.29388.marex-ynQEQJNshbs@public.gmane.org>
2012-04-26 11:42 ` Wolfram Sang
2012-04-26 11:42 ` Wolfram Sang
[not found] ` <20120426114201.GC3548-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2012-04-26 23:10 ` Marek Vasut
2012-04-26 23:10 ` Marek Vasut
[not found] ` <201204270110.21377.marex-ynQEQJNshbs@public.gmane.org>
2012-04-27 14:59 ` Wolfram Sang [this message]
2012-04-27 14:59 ` Wolfram Sang
[not found] ` <20120427145936.GD16504-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2012-04-27 15:08 ` Marek Vasut
2012-04-27 15:08 ` Marek Vasut
[not found] ` <201204271708.53467.marex-ynQEQJNshbs@public.gmane.org>
2012-04-27 15:41 ` Wolfram Sang
2012-04-27 15:41 ` Wolfram Sang
[not found] ` <20120427154119.GF16504-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2012-04-27 15:53 ` Marek Vasut
2012-04-27 15:53 ` Marek Vasut
[not found] ` <201204271753.39516.marex-ynQEQJNshbs@public.gmane.org>
2012-04-27 16:37 ` Wolfram Sang
2012-04-27 16:37 ` Wolfram Sang
[not found] ` <20120427163756.GH16504-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2012-04-28 3:03 ` [TEST PATCH] mxs-i2c DMA support Marek Vasut
2012-04-28 3:03 ` Marek Vasut
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=20120427145936.GD16504@pengutronix.de \
--to=w.sang-bicnvbalz9megne8c9+irq@public.gmane.org \
--cc=festevam-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org \
--cc=linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org \
--cc=linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=marex-ynQEQJNshbs@public.gmane.org \
--cc=shawn.guo-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org \
/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.