[PATCH 2/3] powerpc/esdhc: add property to disable the CMD23

[Huang Changming-R66093]

Best Regards
Jerry Huang


> -----Original Message-----
> From: Chris Ball [mailto:cjb at laptop.org]
> Sent: Wednesday, September 12, 2012 4:59 AM
> To: Kumar Gala
> Cc: Huang Changming-R66093; linuxppc-dev at lists.ozlabs.org list; linux-
> mmc at vger.kernel.org; Anton Vorontsov
> Subject: Re: [PATCH 2/3] powerpc/esdhc: add property to disable the CMD23
> 
> Hi,
> 
> On Tue, Sep 11 2012, Kumar Gala wrote:
> > thanks for the info.  Do you know what's required on controller side
> > to handle cards that support CMD23?
> >
> > I'm trying to figure out if older controller's on FSL SoCs are missing
> > some feature to allow CMD23 to work (vs Auto-CMD23).
> 
> It seems plausible that it's just not implemented on these controllers.
> It's a little strange, since the command's been specified for so long and
> we haven't seen any other controllers with problems.  The patch would be
> correct if this is true.
> 

I didn't find any description about it, but after testing on FSL silicones, I got this result:
Some silicones support this command, and some silicones don't support it, which will cause I/O error.