Re: [PATCH 2/2] i2c: designware: Allow build Baytrail semaphore support when IOSF_MBI=m

["David E. Box" <david.e.box@linux.intel.com>]

Hi

Sorry I missed this discussion. I believe the following code in
i2c_dw_eval_lock_support() should make it so that it doesn't matter how
IOSF_MBI is built:

   if (!iosf_mbi_available())
           return -EPROBE_DEFER;

I added this to address i2c_designware probing before iosf_mbi. It worked but
I do not recall if IOSF_MBI=m was the problem scenario. If so you can just
change it to:

   depends in I2C_DESIGNWARE_PLATFORM && IOSF_MBI
    
Give me a few days to confirm on my Baytrail device. 

David

On Thu, Dec 10, 2015 at 01:48:44PM +0200, Jarkko Nikula wrote:
> I believe i2c-designware-baytrail.c doesn't have strict dependency that
> Intel SoC IOSF Sideband support must be always built-in in order to be
> able to compile support for Intel Baytrail I2C bus sharing HW semaphore.
> 
> Redefine build dependencies so that CONFIG_IOSF_MBI=y is required only
> when CONFIG_I2C_DESIGNWARE_PLATFORM is built-in.
> 
> Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
> ---
> Hi David. Can you ack/nak this patch as I'm not fully familiar with this
> HW semaphore can there be problems when IOSF_MBI is built as a module.
> At least I'm getting similar sensible looking "punit semaphore
> acquired/held for x ms" debug messages when I modprobe/rmmod
> i2c_designware_platform independently is the CONFIG_IOSF_MBI=y or =m.
> ---
>  drivers/i2c/busses/Kconfig | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> index 69c46fe13777..76f4d024def0 100644
> --- a/drivers/i2c/busses/Kconfig
> +++ b/drivers/i2c/busses/Kconfig
> @@ -490,7 +490,9 @@ config I2C_DESIGNWARE_PCI
>  
>  config I2C_DESIGNWARE_BAYTRAIL
>  	bool "Intel Baytrail I2C semaphore support"
> -	depends on I2C_DESIGNWARE_PLATFORM && IOSF_MBI=y && ACPI
> +	depends on ACPI
> +	depends on (I2C_DESIGNWARE_PLATFORM=m && IOSF_MBI) || \
> +		   (I2C_DESIGNWARE_PLATFORM=y && IOSF_MBI=y)
>  	help
>  	  This driver enables managed host access to the PMIC I2C bus on select
>  	  Intel BayTrail platforms using the X-Powers AXP288 PMIC. It allows
> -- 
> 2.6.2
>