Re: [PATCH v2] clk: meson-gxbb: set fclk_div3 as CLK_IS_CRITICAL
From: Stephen Boyd
Date: Thu Nov 08 2018 - 13:12:46 EST
Quoting jbrunet@xxxxxxxxxxxx (2018-11-06 10:49:21)
> On Tue, 2018-11-06 at 10:43 -0800, Stephen Boyd wrote:
> > Quoting Jerome Brunet (2018-11-05 15:08:20)
> > > From: Christian Hewitt <christianshewitt@xxxxxxxxx>
> > >
> > > On the Khadas VIM2 (GXM) and LePotato (GXL) board there are problems
> > > with reboot; e.g. a ~60 second delay between issuing reboot and the
> > > board power cycling (and in some OS configurations reboot will fail
> > > and require manual power cycling).
> > >
> > > Similar to 'commit c987ac6f1f088663b6dad39281071aeb31d450a8 ("clk:
> > > meson-gxbb: set fclk_div2 as CLK_IS_CRITICAL")' the SCPI Cortex-M4
> > > Co-Processor seems to depend on FCLK_DIV3 being operational.
> > >
> > > Until commit 05f814402d6174369b3b29832cbb5eb5ed287059 ("clk:
> > > meson: add fdiv clock gates"), this clock was modeled and left on by
> > > the bootloader.
> > >
> > > We don't have precise documentation about the SCPI Co-Processor and
> > > its clock requirement so we are learning things the hard way.
> > >
> > > Marking this clock as critical solves the problem but it should not
> > > be viewed as final solution. Ideally, the SCPI driver should claim
> > > these clocks. We also depends on some clock hand-off mechanism
> > > making its way to CCF, to make sure the clock stays on between its
> > > registration and the SCPI driver probe.
> > >
> > > Fixes: 05f814402d61 ("clk: meson: add fdiv clock gates")
> > > Signed-off-by: Christian Hewitt <christianshewitt@xxxxxxxxx>
> > > Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
> > > ---
> >
> > I can toss this into clk-fixes?
> >
>
> Sure, it would be great. Thx Stephen.
>
>
Awesome, thanks! Applied to clk-fixes.