Re: [linux-sunxi] [PATCH] ARM: sunxi: Fix CPU powerdown on A83T

From: OndÅej Jirman
Date: Mon Oct 28 2019 - 21:25:21 EST


On Tue, Oct 29, 2019 at 09:09:40AM +0800, Chen-Yu Tsai wrote:
> On Tue, Oct 29, 2019 at 5:49 AM Ondrej Jirman <megous@xxxxxxxxxx> wrote:
> >
> > PRCM_PWROFF_GATING_REG has CPU0 at bit 4 on A83T. So without this
> > patch, instead of gating the CPU0, the whole cluster was power gated,
> > when shutting down first CPU in the cluster.
> >
> > Fixes: 6961275e72a8c1 ("ARM: sun8i: smp: Add support for A83T")
> > Signed-off-by: Ondrej Jirman <megous@xxxxxxxxxx>
> > Cc: stable@xxxxxxxxxxxxxxx
>
> Acked-by: Chen-Yu Tsai <wens@xxxxxxxx>
>
> Though I distinctly remember the BSP had some code dealing with chip
> revisions in which the two bits were reversed. :(

Actually, it's a bit more complicated. There's a special check in BSP
code (grep for SUN8IW6P1_REV_A) that instead of power gating, just
holds the core in reset for that revision.

regards,
o.