[PATCH 1/2] clk: renesas: Do not enable MSTP4 modules on R8A77995 D3

Niklas Söderlund niklas.soderlund+renesas at ragnatech.se
Sun Dec 28 09:12:24 CET 2025


On 2025-12-28 03:03:31 +0100, Marek Vasut wrote:
> On 12/28/25 2:03 AM, Niklas Söderlund wrote:
> > Since commit a2bd99549c61 ("clk: renesas: Tear clock controller down
> > last before booting OS") enabling the module gated by bit 8 in MSTP4
> > prevents Linux from booting. Furthermore bits 8 and 7 of MSTP4 where
> > only documented in early versions of the datasheet and have since been
> > removed, do the same in the driver to allow Linux to boot.
> > 
> > Suggested-by: Marek Vasut <marek.vasut+renesas at mailbox.org>
> > Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas at ragnatech.se>
> > ---
> >   drivers/clk/renesas/r8a77995-cpg-mssr.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/clk/renesas/r8a77995-cpg-mssr.c b/drivers/clk/renesas/r8a77995-cpg-mssr.c
> > index f49faa47cb37..0a59a19cb227 100644
> > --- a/drivers/clk/renesas/r8a77995-cpg-mssr.c
> > +++ b/drivers/clk/renesas/r8a77995-cpg-mssr.c
> > @@ -220,7 +220,7 @@ static const struct mstp_stop_table r8a77995_mstp_table[] = {
> >   	{ 0x03e01000, 0x0, 0x03e01000, 0 },
> >   	{ 0x000e2fdc, 0x2000, 0x000e2fd8, 0 },
> >   	{ 0xc00014df, 0x400, 0xc00014df, 0 },
> > -	{ 0x80000004, 0x180, 0x80000004, 0 },
> > +	{ 0x80000004, 0x0, 0x80000004, 0 },
> Should we disable both BIT(8) and BIT(7), or only the BIT(8) that hangs the
> system ?

I think we shall remove both as the datasheet removes both, no?

-- 
Kind Regards,
Niklas Söderlund


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