Re: [PATCH] soc: bcm: brcmstb: Remove bare-metal ARM suspend/resume code

[Florian Fainelli]

On 2/27/2023 10:36 AM, Guilherme G. Piccoli wrote:
> On 24/02/2023 18:52, Florian Fainelli wrote:
> > Since 2018 these platforms have supported entry via the ARM Trusted
> > Firmware using the standard PSCI SYSTEM_SUSPEND function calls. Remove
> > this legacy code.
> >
> > Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
> > [...]
> > -/*
> > - * The AON is a small domain in the SoC that can retain its state across
> > - * various system wide sleep states and specific reset conditions; the
> > - * AON DATA RAM is a small RAM of a few words (< 1KB) which can store
> > - * persistent information across such events.
> > - *
> > - * The purpose of the below panic notifier is to help with notifying
> > - * the bootloader that a panic occurred and so that it should try its
> > - * best to preserve the DRAM contents holding that buffer for recovery
> > - * by the kernel as opposed to wiping out DRAM clean again.
> > - *
> > - * Reference: comment from Florian Fainelli, at
> > - * https://lore.kernel.org/lkml/781cafb0-8d06-8b56-907a-5175c2da196a@xxxxxxxxx
> > - */
> > -static int brcmstb_pm_panic_notify(struct notifier_block *nb,
> > -		unsigned long action, void *data)
> > -{
> > -	writel_relaxed(BRCMSTB_PANIC_MAGIC, ctrl.aon_sram + AON_REG_PANIC);
> > -
> > -	return NOTIFY_DONE;
> > [...]
>
> Hi Florian, thanks for the clean-up!
>
> I'm curious with the above panic notifier - is it not necessary when
> PSCI is used?

This is a bit of long story, but no, it is not necessary.
--
Florian