[PATCH v6 2/2] ARM: imx: Add suspend codes for imx7D

[Shenwei Wang]

> -----Original Message-----
> From: Shawn Guo [mailto:shawnguo at kernel.org]
> Sent: 2015年7月27日 20:03
> To: Wang Shenwei-B38339
> Cc: jason at lakedaemon.net; Huang Yongcai-B20788;
> linux-kernel at vger.kernel.org; tglx at linutronix.de; shawn.guo at linaro.org;
> linux-arm-kernel at lists.infradead.org
> Subject: Re: [PATCH v6 2/2] ARM: imx: Add suspend codes for imx7D
> 
> On Mon, Jul 27, 2015 at 06:24:26PM +0000, Shenwei Wang wrote:
> > > > @@ -87,6 +87,8 @@ obj-$(CONFIG_SOC_IMX7D) += mach-imx7d.o
> > > >
> > > >  ifeq ($(CONFIG_SUSPEND),y)
> > > >  AFLAGS_suspend-imx6.o :=-Wa,-march=armv7-a
> > > > +AFLAGS_suspend-imx7.o :=-Wa,-march=armv7-a
> > > > +obj-$(CONFIG_IMX_GPCV2)	+= suspend-imx7.o pm-imx7.o
> > >
> > > Shouldn't it be controlled by CONFIG_SOC_IMX7D instead?
> >
> > CONFIG_IMX_GPCV2 is more suitable here. As long as a SOC has the same
> GPCv2 block, the codes should be reused.
> 
> Let's see what problem it will have.  Saying GPCv2 block is used on imx8, we will
> have something like below.
> 
> obj-$(CONFIG_IMX_GPCV2) += suspend-imx7.o pm-imx7.o suspend-imx8.o
> pm-imx8.o

I don't think so. If imx8 use the same GPCv2 block, there should be no pm-imx8.o and suspend-imx8.o.
We should try to reuse the existing ones.
 
> If people want to build a kernel with imx8 support only, suspend-imx7.o and
> pm-imx7.o will also be built in there, which is undesirable.
> 
> The files are named with "-imx7".  It's a clear sign that the build of the files
> should be controlled by something like related to "imx7".
> Ideally, it should be CONFIG_SOC_IMX7.  Since imx7d is the only supported imx7
> soc and there is no CONFIG_SOC_IMX7 available so far, it falls on
> CONFIG_SOC_IMX7D.

We can also interpret "-imx7" is the first SoC which has the GPCv2 block. 

> > > > +extern struct imx_gpcv2_irq *gpcv2_irq_instance;
> > >
> > > Will this give a checkpatch warning?
> >
> > Yes. Any suggestion for that? Move it to a header file?
> 
> Get rid of it.

Then you may resolve the following compile error:

CC      arch/arm/mach-imx/pm-imx7.o
arch/arm/mach-imx/pm-imx7.c: In function ‘imx_gpcv2_pm_init’:
arch/arm/mach-imx/pm-imx7.c:836:7: error: ‘gpcv2_irq_instance’ undeclared (first use in this function)
  cd = gpcv2_irq_instance;
       ^
arch/arm/mach-imx/pm-imx7.c:836:7: note: each undeclared identifier is reported only once for each function it appears in
make[1]: *** [arch/arm/mach-imx/pm-imx7.o] Error 1

Regards,
Shenwei

> Shawn