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

[Marek Vasut]

On 12/28/25 9:12 AM, Niklas Söderlund wrote:
> 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?
Drop only bit 8 please, bit 7 is set so keep it set.