RE: [PATCH v4 05/13] pm: at91: move the copying the sram function to the sram initializationi phase

[Yang, Wenyou]

Hi  Alexandre,

> -----Original Message-----
> From: Alexandre Belloni [mailto:alexandre.belloni@xxxxxxxxxxxxxxxxxx]
> Sent: Thursday, January 29, 2015 11:09 PM
> To: Russell King - ARM Linux
> Cc: Yang, Wenyou; Ferre, Nicolas; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; sylvain.rochet@xxxxxxxxxxxx; peda@xxxxxxxxxx;
> sergei.shtylyov@xxxxxxxxxxxxxxxxxx; linux@xxxxxxxxxxxx
> Subject: Re: [PATCH v4 05/13] pm: at91: move the copying the sram function to
> the sram initializationi phase
> 
> Hi,
> 
> On 29/01/2015 at 11:28:00 +0000, Russell King - ARM Linux wrote :
> > On Wed, Jan 28, 2015 at 09:43:16AM +0800, Wenyou Yang wrote:
> > > -#ifdef CONFIG_AT91_SLOW_CLOCK
> > > -				/* copy slow_clock handler to SRAM, and call it */
> > > -				memcpy(slow_clock, at91_slow_clock,
> at91_slow_clock_sz);
> > > -#endif
> > >  				slow_clock(at91_pmc_base, at91_ramc_base[0],
> > >  					   at91_ramc_base[1],
> > >  					   at91_pm_data.memctrl);
> > > @@ -272,6 +268,9 @@ static void __init at91_pm_sram_init(void)
> > >  	sram_pbase = gen_pool_virt_to_phys(sram_pool, sram_base);
> > >  	slow_clock = __arm_ioremap_exec(sram_pbase, at91_slow_clock_sz,
> > > false);
> > >
> > > +	/* Copy the slow_clock handler to SRAM */
> > > +	memcpy(slow_clock, at91_slow_clock, at91_slow_clock_sz);
> > > +
> >
> > Why is this code not using the fncpy() support for copying functions.
> 
> Indeed, this was done in the original version of the patch that I acked.
Yes, in the original version used the fncpy(), but it works not well for some SoCs.
Sorry for that, I forget to record it on the change log.

> 
> > Why is it not checking the return code from __arm_ioremap_exec() or
> > gen_pool_virt_to_phys() for failure?
> 
> gen_pool_virt_to_phys() will not fail as the chunk is allocated just before so it will
> necessarily be found in the list.
> 
> We need to reintroduce a check for slow_clock != NULL before fncpy() since it is
> moved out of its original if block.
> 
> --
> Alexandre Belloni, Free Electrons
> Embedded Linux, Kernel and Android engineering http://free-electrons.com

Best Regards,
Wenyou yang
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