From: Arnd Bergmann <arnd@arndb.de>
To: Maxime Ripard <maxime.ripard@free-electrons.com>
Subject: Re: [PATCH v10 2/2] dmaengine: sun6i: Add driver for the Allwinner A31 DMA controller
Date: Sun, 6 Jul 2014 17:22:00 +0200
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Cc: Mark Rutland <mark.rutland@arm.com>,
        Dan Williams <dan.j.williams@intel.com>,
        Vinod Koul <vinod.koul@intel.com>,
        "andriy.shevchenko@intel.com" <andriy.shevchenko@intel.com>,
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        "zhuzhenhua@allwinnertech.com" <zhuzhenhua@allwinnertech.com>,
        "dmaengine@vger.kernel.org" <dmaengine@vger.kernel.org>,
        "linux-sunxi@googlegroups.com" <linux-sunxi@googlegroups.com>,
        "kevin.z.m.zh@gmail.com" <kevin.z.m.zh@gmail.com>,
        "sunny@allwinnertech.com" <sunny@allwinnertech.com>,
        "shuge@allwinnertech.com" <shuge@allwinnertech.com>,
        "linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>
References: <1404134454-25513-1-git-send-email-maxime.ripard@free-electrons.com> <20140701124852.GB6064@leverpostej> <20140704075710.GN31996@lukather>
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On Friday 04 July 2014, Maxime Ripard wrote:
> > > > It feels a little fragile to rely on the organisation of the clock tree
> > > > and the naming thereof. If the IP block is ever reused on an SoC with a
> > > > different clock tree layout then we have to handle things differently.
> > > 
> > > What do you suggest then?
> > 
> > I will admit that I don't have a better suggestion.
> > 
> > Without knowing which particular constraint on the mux parent clock we
> > care about it's difficult to suggest anything useful.
> 
> Well, I first made it into the mach- directory, and then was told to
> move it in the driver itself, so we're kind of running out of options
> :)

How about having a property in the clock provider node that forces a
specific value for the mux? I think that's generally the preferred solution
for any clock settings that go beyond what an OS can be expected to figure
out for itself.

	Arnd
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