[RFC 0/5] restart cleanups

[Kukjin Kim]

Russell King - ARM Linux wrote:
> 
> On Tue, Nov 01, 2011 at 04:38:17PM +0000, Russell King - ARM Linux wrote:
> > Can someone please check whether this code:
> >
> > /* Hook for arm_pm_restart to ensure we execute the reset code
> >  * with the caches enabled. It seems at least the S3C2440 has a problem
> >  * resetting if there is bus activity interrupted by the reset.
> >  */
> > static void s3c24xx_pm_restart(char mode, const char *cmd)
> > {
> >         if (mode != 's') {
> >                 unsigned long flags;
> >
> >                 local_irq_save(flags);
> >                 __cpuc_flush_kern_all();
> >                 __cpuc_flush_user_all();
> >
> >                 arch_reset(mode, cmd);
> >                 local_irq_restore(flags);
> >         }
> >
> >         /* fallback, or unhandled */
> >         arm_machine_restart(mode, cmd);
> > }
> >
> > will be broken by any of these patches - and more importantly whether
> > this code can simply be deleted with these five patches applied.
> 
> Okay, I'm going to delete the above and hope for the best; I'm taking
> the lack of reply as meaning that no one in the Samsung community is
> that interested in this code.

Russell,
Sorry for late response.

According to its commit message, it is needed...

[ARM] 4987/1: S3C24XX: Ensure watchdog reset initiated from cached code.

    There seems to be some problem with at-least the S3C2440 and
    bus traffic during an reset. It is unlikely, but still possible
    that the system will hang in such a way that the watchdog cannot
    get the system out of the state it is in.

    Change to making the code that calls the watchdog reset run from
    cached memory so that instruction fetches have quiesced before the
    watchdog fires.

But frankly, I'm not sure now and there is no S3C2440 on my desk :(
Let me check again, if no response on this, please keep going on.

Thanks.

Best regards,
Kgene.
--
Kukjin Kim <kgene.kim at samsung.com>, Senior Engineer,
SW Solution Development Team, Samsung Electronics Co., Ltd.