2022-04-29 23:57:57

by Christian Marangi

Subject: [PATCH 2/4] clk: qcom: clk-krait: unlock spin after mux completion

Unlock spinlock after the mux switch is completed to prevent any corner
case of mux request while the switch still needs to be done.

Fixes: 4d7dc77babfe ("clk: qcom: Add support for Krait clocks")
Signed-off-by: Ansuel Smith <[email protected]>
---
drivers/clk/qcom/clk-krait.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/qcom/clk-krait.c b/drivers/clk/qcom/clk-krait.c
index 59f1af415b58..90046428693c 100644
--- a/drivers/clk/qcom/clk-krait.c
+++ b/drivers/clk/qcom/clk-krait.c
@@ -32,11 +32,16 @@ static void __krait_mux_set_sel(struct krait_mux_clk *mux, int sel)
regval |= (sel & mux->mask) << (mux->shift + LPL_SHIFT);
}
krait_set_l2_indirect_reg(mux->offset, regval);
- spin_unlock_irqrestore(&krait_clock_reg_lock, flags);

/* Wait for switch to complete. */
mb();
udelay(1);
+
+ /*
+ * Unlock now to make sure the mux register is not
+ * modified while switching to the new parent.
+ */
+ spin_unlock_irqrestore(&krait_clock_reg_lock, flags);
}

static int krait_mux_set_parent(struct clk_hw *hw, u8 index)
--
2.34.1

2022-05-03 00:15:47

by Dmitry Baryshkov

Subject: Re: [PATCH 2/4] clk: qcom: clk-krait: unlock spin after mux completion

On 29/04/2022 15:01, Ansuel Smith wrote:
> Unlock spinlock after the mux switch is completed to prevent any corner
> case of mux request while the switch still needs to be done.
>
> Fixes: 4d7dc77babfe ("clk: qcom: Add support for Krait clocks")
> Signed-off-by: Ansuel Smith <[email protected]>

Reviewed-by: Dmitry Baryshkov <[email protected]>

> ---
> drivers/clk/qcom/clk-krait.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/clk/qcom/clk-krait.c b/drivers/clk/qcom/clk-krait.c
> index 59f1af415b58..90046428693c 100644
> --- a/drivers/clk/qcom/clk-krait.c
> +++ b/drivers/clk/qcom/clk-krait.c
> @@ -32,11 +32,16 @@ static void __krait_mux_set_sel(struct krait_mux_clk *mux, int sel)
> regval |= (sel & mux->mask) << (mux->shift + LPL_SHIFT);
> }
> krait_set_l2_indirect_reg(mux->offset, regval);
> - spin_unlock_irqrestore(&krait_clock_reg_lock, flags);
>
> /* Wait for switch to complete. */
> mb();
> udelay(1);
> +
> + /*
> + * Unlock now to make sure the mux register is not
> + * modified while switching to the new parent.
> + */
> + spin_unlock_irqrestore(&krait_clock_reg_lock, flags);
> }
>
> static int krait_mux_set_parent(struct clk_hw *hw, u8 index)


--
With best wishes
Dmitry