Re: [PATCH V2 05/19] bus: omap_l3_noc: switch over to relaxed variants of readl/writel

From: Felipe Balbi
Date: Mon Apr 21 2014 - 11:12:26 EST


On Mon, Apr 21, 2014 at 08:16:28AM -0500, Nishanth Menon wrote:
> On 04/17/2014 05:03 PM, Felipe Balbi wrote:
> > On Thu, Apr 17, 2014 at 05:56:15PM -0400, Santosh Shilimkar wrote:
> >> On Thursday 17 April 2014 05:52 PM, Felipe Balbi wrote:
> >>> Hi,
> >>>
> >>> On Thu, Apr 17, 2014 at 03:49:21PM -0500, Nishanth Menon wrote:
> >>>> Currently we use __raw_readl and writel in this driver, however, there
> >>>
> >>> __raw_* and *_relaxed variants are the same, just have a look <asm/io.h>
> >>>
> >> Except the relaxed version can take care of endian conversion if
> >> needed. :-)
> >
> > right, but according to commit log, this commit is more concerned about
> > the memory barriers which writel()/readl() add, not endianness. Just a
> > matter of fixing up commit log.
> >
>
> yep, this patch does replace writel with writel_relaxed there is no
> strong need for barriers in the operations that we perform here.
>
> I agree that the commit message should probably be a little more
> detailed at this point.
>
>
> How about:
> Currently we use __raw_readl and writel in this driver. Considering
> there is no specific need for a memory barrier, replacing writel with
> endian-neutral writel_relaxed and replacing __raw_readls with the
> corresponding endian-neutral readl_relaxed allows us to have a
> standard set of register operations for the driver.
>
> While at it, simplify address computation using variables for register.

reads a lot better, thanks

Acked-by: Felipe Balbi <balbi@xxxxxx>


--
balbi

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