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Message-ID: <aEeXepzJ2Qkv45qm@ketchup>
Date: Tue, 10 Jun 2025 02:24:58 +0000
From: Haylen Chu <heylenay@....org>
To: Alex Elder <elder@...cstar.com>, mturquette@...libre.com,
sboyd@...nel.org
Cc: dlan@...too.org, inochiama@...look.com, linux-clk@...r.kernel.org,
spacemit@...ts.linux.dev, linux-riscv@...ts.infradead.org,
linux-kernel@...r.kernel.org, Guodong Xu <guodong@...cstar.com>
Subject: Re: [PATCH] clk: spacemit: mark K1 pll1_d8 as critical
On Mon, Jun 09, 2025 at 03:08:21PM -0500, Alex Elder wrote:
> The pll1_d8 clock is enabled by the boot loader, and is ultimately a
> parent for numerous clocks, including those used by APB and AXI buses.
> Guodong Xu discovered that this clock got disabled while responding to
> getting -EPROBE_DEFER when requesting a reset controller.
>
> The needed clock (CLK_DMA, along with its parents) had already been
> enabled. To respond to the probe deferral return, the CLK_DMA clock
> was disabled, and this led to parent clocks also reducing their enable
> count. When the enable count for pll1_d8 was decremented it became 0,
> which caused it to be disabled. This led to a system hang.
>
> Marking that clock critical resolves this by preventing it from being
> disabled.
>
> Define a new macro CCU_FACTOR_GATE_DEFINE() to allow clock flags to
> be supplied for a CCU_FACTOR_GATE clock.
>
> Fixes: 1b72c59db0add ("clk: spacemit: Add clock support for SpacemiT K1 SoC")
> Signed-off-by: Alex Elder <elder@...cstar.com>
> Tested-by: Guodong Xu <guodong@...cstar.com>
> ---
> v2: Reworded the description to provide better detail
>
> drivers/clk/spacemit/ccu-k1.c | 3 ++-
> drivers/clk/spacemit/ccu_mix.h | 21 +++++++++++++--------
> 2 files changed, 15 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/clk/spacemit/ccu-k1.c b/drivers/clk/spacemit/ccu-k1.c
> index cdde37a052353..df65009a07bb1 100644
> --- a/drivers/clk/spacemit/ccu-k1.c
> +++ b/drivers/clk/spacemit/ccu-k1.c
> @@ -170,7 +170,8 @@ CCU_FACTOR_GATE_DEFINE(pll1_d4, CCU_PARENT_HW(pll1), APBS_PLL1_SWCR2, BIT(3), 4,
> CCU_FACTOR_GATE_DEFINE(pll1_d5, CCU_PARENT_HW(pll1), APBS_PLL1_SWCR2, BIT(4), 5, 1);
> CCU_FACTOR_GATE_DEFINE(pll1_d6, CCU_PARENT_HW(pll1), APBS_PLL1_SWCR2, BIT(5), 6, 1);
> CCU_FACTOR_GATE_DEFINE(pll1_d7, CCU_PARENT_HW(pll1), APBS_PLL1_SWCR2, BIT(6), 7, 1);
> -CCU_FACTOR_GATE_DEFINE(pll1_d8, CCU_PARENT_HW(pll1), APBS_PLL1_SWCR2, BIT(7), 8, 1);
> +CCU_FACTOR_GATE_FLAGS_DEFINE(pll1_d8, CCU_PARENT_HW(pll1), APBS_PLL1_SWCR2, BIT(7), 8, 1,
> + CLK_IS_CRITICAL);
> CCU_FACTOR_GATE_DEFINE(pll1_d11_223p4, CCU_PARENT_HW(pll1), APBS_PLL1_SWCR2, BIT(15), 11, 1);
> CCU_FACTOR_GATE_DEFINE(pll1_d13_189, CCU_PARENT_HW(pll1), APBS_PLL1_SWCR2, BIT(16), 13, 1);
> CCU_FACTOR_GATE_DEFINE(pll1_d23_106p8, CCU_PARENT_HW(pll1), APBS_PLL1_SWCR2, BIT(20), 23, 1);
> diff --git a/drivers/clk/spacemit/ccu_mix.h b/drivers/clk/spacemit/ccu_mix.h
> index 51d19f5d6aacb..668c8139339e1 100644
> --- a/drivers/clk/spacemit/ccu_mix.h
> +++ b/drivers/clk/spacemit/ccu_mix.h
> @@ -101,16 +101,21 @@ static struct ccu_mix _name = { \
> } \
> }
>
> +#define CCU_FACTOR_GATE_FLAGS_DEFINE(_name, _parent, _reg_ctrl, _mask_gate, _div, \
> + _mul, _flags) \
> +struct ccu_mix _name = { \
This should be defined as static as well. I think this is the cause of
CI warnings in v1.
With this fixed,
Reviewed-by: Haylen Chu <heylenay@....org>
> + .gate = CCU_GATE_INIT(_mask_gate), \
> + .factor = CCU_FACTOR_INIT(_div, _mul), \
> + .common = { \
> + .reg_ctrl = _reg_ctrl, \
> + CCU_MIX_INITHW(_name, _parent, spacemit_ccu_factor_gate_ops, _flags) \
> + } \
> +}
> +
> #define CCU_FACTOR_GATE_DEFINE(_name, _parent, _reg_ctrl, _mask_gate, _div, \
> _mul) \
> -static struct ccu_mix _name = { \
> - .gate = CCU_GATE_INIT(_mask_gate), \
> - .factor = CCU_FACTOR_INIT(_div, _mul), \
> - .common = { \
> - .reg_ctrl = _reg_ctrl, \
> - CCU_MIX_INITHW(_name, _parent, spacemit_ccu_factor_gate_ops, 0) \
> - } \
> -}
> + CCU_FACTOR_GATE_FLAGS_DEFINE(_name, _parent, _reg_ctrl, _mask_gate, _div, \
> + _mul, 0)
>
> #define CCU_MUX_GATE_DEFINE(_name, _parents, _reg_ctrl, _shift, _width, \
> _mask_gate, _flags) \
>
> base-commit: 19272b37aa4f83ca52bdf9c16d5d81bdd1354494
> --
> 2.45.2
>
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