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 17:41:19 +0200 [thread overview]
Message-ID: <20120427154119.GF16504@pengutronix.de> (raw)
In-Reply-To: <201204271708.53467.marex-ynQEQJNshbs@public.gmane.org>
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> You can get a large list of i2c messages. In the current implementation, yes,
> they're iterated in mxs_i2c_xfer_msg. Correct.
>
> If you want to do DMA transfer do/from the i2c controller, you have to take all
> these messages and create the chain of DMA transfers according to these
> messages, correct?
This is what I wonder. I'd think one could work on a per message basis.
Regarding Figure 27-10, the first I2C write command could be sent
seperately (probably even via PIOQUEUE). The only thing to be chained is
the I2C read command and the actual reading of the data.
Just checked, the FSL driver does it basically this way, too.
--
Pengutronix e.K. | Wolfram Sang |
Industrial Linux Solutions | http://www.pengutronix.de/ |
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next prev parent reply other threads:[~2012-04-27 15:41 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <201204261326.29388.marex@denx.de>
[not found] ` <201204261326.29388.marex-ynQEQJNshbs@public.gmane.org>
2012-04-26 11:42 ` possible MXS-i2c bug Wolfram Sang
[not found] ` <20120426114201.GC3548-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2012-04-26 23:10 ` Marek Vasut
[not found] ` <201204270110.21377.marex-ynQEQJNshbs@public.gmane.org>
2012-04-27 14:59 ` Wolfram Sang
[not found] ` <20120427145936.GD16504-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2012-04-27 15:08 ` Marek Vasut
[not found] ` <201204271708.53467.marex-ynQEQJNshbs@public.gmane.org>
2012-04-27 15:41 ` Wolfram Sang [this message]
[not found] ` <20120427154119.GF16504-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2012-04-27 15:53 ` Marek Vasut
[not found] ` <201204271753.39516.marex-ynQEQJNshbs@public.gmane.org>
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
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