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

[Anil Kumar <anilk4.v@gmail.com>]

Hi,

On Fri, Feb 15, 2013 at 10:31 PM, Ezequiel Garcia
<ezequiel.garcia@free-electrons.com> wrote:
> 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@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@ti.com>
>> > Signed-off-by: Ezequiel Garcia <ezequiel.garcia@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.
>

Yes, with patch  "ARM: OMAP2+: Fix-up gpmc merge error" now nand is
detected on my
devkit8000(omap3 based board) with DT boot.

Thank you very much.
Anil