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

Huang Changming-R66093 r66093 at freescale.com
Thu Sep 13 12:02:30 EST 2012


> >
> >> -----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.
> 
> Can you list out which SoCs support it and which don't.  Having this list
> will be useful in understanding which controller versions supported it.
> 
P1020, p1021, p1022, p1024, p1015 and p4080 can't support it.
Mpc8536, p2020, and the other current DPAA silicon (e.g. p5020, p3041) support it.



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