Re: [PATCH v5 03/13] mmc: provide a standard MMC device-tree binding parser centrally

[Guennadi Liakhovetski <g.liakhovetski@gmx.de>]

On Sun, 17 Feb 2013, Simon Horman wrote:

> On Sun, Feb 17, 2013 at 04:52:16PM +0900, Simon Horman wrote:
> > On Sat, Feb 16, 2013 at 05:58:25PM +0100, Sascha Hauer wrote:
> > > Hi Guennadi,
> > > 
> > > On Sat, Feb 16, 2013 at 04:21:16PM +0100, Guennadi Liakhovetski wrote:
> > > > MMC defines a number of standard DT bindings. Having each driver parse
> > > > them individually adds code redundancy and is error prone. Provide a
> > > > standard function to unify the parsing. After all drivers are converted
> > > > to using it instead of their own parsers, this function can be integrated
> > > > into mmc_alloc_host().
> > > > 
> > > > Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
> > > > ---
> > > > 
> > > > v5:
> > > > 
> > > > 1. fix an uninitialised variable warning. Note, I don't actually know, 
> > > > whether this will fix the error, reported by the kbuild test robot. None 
> > > > of my compilers reports an error there, at most, I've got a warning with 
> > > > one of them, and, surprisingly, it is gone after this change. 
> > > > Surprisingly, because I only add the bus_width initialisation in the error 
> > > > case - exactly as it actually has to be done. In the success case it is 
> > > > assigned set by the function. But the compiler cannot know that!
> > > 
> > > Maybe the build robot builds with devicetree disabled? In this case
> > > of_property_read_u32_array expands to a static inline function and the
> > > compiler indeed knows that &bus_width is unitialized. It also knows that
> > > this function always returns an error, so what you did below should
> > > silence the compiler.
> > 
> > It seems so. The configuration that flagged the error was atngw100_defconfig.
> > 
> > ARCH=avr32 make atngw100_defconfig
> > grep USE_OF .config
> > [nothing]
> 
> In that vein I managed to reproduce the warning using ap4evb_defconfig
> and then enabled MMC. I have also verified that v5 does not produce
> the same warning.
> 
> I chose this as I don't have a avr32 cross-compile environment
> but I do have one for ARM and I know that ap4evb doesn't use DT.
> 
> I will update topic/mmc with v5.

Very good, thanks! So, this way I think, v5 should be ok.

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/