[PATCH v2 3/8] ARM: omap2: gpmc: Fix gpmc_cs_reserved() return value

[Ezequiel Garcia]

Hi Anil,

On Fri, Feb 15, 2013 at 09:49:21PM +0530, Anil Kumar wrote:
> Hi,
> 
> On Tue, Feb 12, 2013 at 8:48 PM, Ezequiel Garcia
> <ezequiel.garcia at free-electrons.com> wrote:
> > Currently gpmc_cs_reserved() return value is somewhat inconsistent,
> > returning a negative value on an error condition, a positive value
> > if the chip select is reserved and zero if it's available.
> >
> > Fix this by returning a boolean value as the function name suggests:
> >   * true if the chip select is reserved,
> >   * false if it's available
> >
> > Suggested-by: Felipe Balbi <balbi at ti.com>
> > Signed-off-by: Ezequiel Garcia <ezequiel.garcia at free-electrons.com>
> > ---
> > Changelog from v1:
> >  * As suggested by Felipe Balbi, fix return code to a boolean
> >
> >  arch/arm/mach-omap2/gpmc.c |    4 ++--
> >  1 files changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
> > index bd3bc93..fa4764f 100644
> > --- a/arch/arm/mach-omap2/gpmc.c
> > +++ b/arch/arm/mach-omap2/gpmc.c
> > @@ -452,10 +452,10 @@ static int gpmc_cs_set_reserved(int cs, int reserved)
> >         return 0;
> >  }
> >
> > -static int gpmc_cs_reserved(int cs)
> > +static bool gpmc_cs_reserved(int cs)
> >  {
> >         if (cs > GPMC_CS_NUM)
> > -               return -ENODEV;
> > +               return true;
> >
> >         return gpmc_cs_map & (1 << cs);
> >  }
> 
> commit "6797b4fe0e554ce71f47038fd929c9ca929a9f3c"
> Marking all the chip-selects as reserved by default.
> 
> In this case gpmc_cs_map is 0xff. So it will return 0x1 if cs is 0.
> So gpmc_cs_request() function will fail in nand (gpmc-nand.c) case.
> 
> I am taking reference, branch "omap-for-v3.9/gpmc" of git tree
> http://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap.git
> 
> I am sorry if this question is very vague.
> 

If I understand correctly your concern, I believe you've missed this
patch submitted by Jon Hunter and not yet merged:

  ARM: OMAP2+: Fix-up gpmc merge error

With this patch every chip-select is cleared on gpmc_probe()
as soon as GPMC driver initializes, and before we can request any
NAND/NOR child.

I hope this answers your question.

Feel free to test the series and send your Tested-by!

Thanks,
-- 
Ezequiel García, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com