From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

If MSTOP is not added for both clocks in a coupled pair, and the clocks
are not disabled in the reverse order of their enable sequence, the MSTOP
may remain enabled when disabling the clocks.

This happens because rzg2l_mod_clock_endisable() executes for coupled
clocks only when a single clock from the pair is enabled. If one clock has
no MSTOP defined, it can result in the MSTOP configuration being left
active when the clocks are disabled out of order (i.e., not in the reverse
order of enabling).

Fixes: c49695952746 ("clk: renesas: r9a08g045: Drop power domain instantiation")
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
---
 drivers/clk/renesas/r9a08g045-cpg.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/renesas/r9a08g045-cpg.c b/drivers/clk/renesas/r9a08g045-cpg.c
index 405907925bb7..ed0661997928 100644
--- a/drivers/clk/renesas/r9a08g045-cpg.c
+++ b/drivers/clk/renesas/r9a08g045-cpg.c
@@ -256,11 +256,13 @@ static const struct rzg2l_mod_clk r9a08g045_mod_clks[] = {
 					MSTOP(BUS_PERI_COM, BIT(4))),
 	DEF_COUPLED("eth0_axi",		R9A08G045_ETH0_CLK_AXI, R9A08G045_CLK_M0, 0x57c, 0,
 					MSTOP(BUS_PERI_COM, BIT(2))),
-	DEF_COUPLED("eth0_chi",		R9A08G045_ETH0_CLK_CHI, R9A08G045_CLK_ZT, 0x57c, 0, 0),
+	DEF_COUPLED("eth0_chi",		R9A08G045_ETH0_CLK_CHI, R9A08G045_CLK_ZT, 0x57c, 0,
+					MSTOP(BUS_PERI_COM, BIT(2))),
 	DEF_MOD("eth0_refclk",		R9A08G045_ETH0_REFCLK, R9A08G045_CLK_HP, 0x57c, 8, 0),
 	DEF_COUPLED("eth1_axi",		R9A08G045_ETH1_CLK_AXI, R9A08G045_CLK_M0, 0x57c, 1,
 					MSTOP(BUS_PERI_COM, BIT(3))),
-	DEF_COUPLED("eth1_chi",		R9A08G045_ETH1_CLK_CHI, R9A08G045_CLK_ZT, 0x57c, 1, 0),
+	DEF_COUPLED("eth1_chi",		R9A08G045_ETH1_CLK_CHI, R9A08G045_CLK_ZT, 0x57c, 1,
+					MSTOP(BUS_PERI_COM, BIT(3))),
 	DEF_MOD("eth1_refclk",		R9A08G045_ETH1_REFCLK, R9A08G045_CLK_HP, 0x57c, 9, 0),
 	DEF_MOD("i2c0_pclk",		R9A08G045_I2C0_PCLK, R9A08G045_CLK_P0, 0x580, 0,
 					MSTOP(BUS_MCPU2, BIT(10))),
-- 
2.43.0

On Fri, 4 Jul 2025 at 15:43, Claudiu <claudiu.beznea@tuxon.dev> wrote:
> From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
>
> If MSTOP is not added for both clocks in a coupled pair, and the clocks
> are not disabled in the reverse order of their enable sequence, the MSTOP
> may remain enabled when disabling the clocks.
>
> This happens because rzg2l_mod_clock_endisable() executes for coupled
> clocks only when a single clock from the pair is enabled. If one clock has
> no MSTOP defined, it can result in the MSTOP configuration being left
> active when the clocks are disabled out of order (i.e., not in the reverse
> order of enabling).
>
> Fixes: c49695952746 ("clk: renesas: r9a08g045: Drop power domain instantiation")
> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
i.e. will queue in renesas-clk for v6.17.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds