Re: Patch "clk: Respect CLK_OPS_PARENT_ENABLE during recalc" has been added to the 6.19-stable tree

[Nicolas Frattaroli <nicolas.frattaroli@collabora.com>]

On Saturday, 21 February 2026 17:03:09 Central European Standard Time Sasha Levin wrote:
> This is a note to let you know that I've just added the patch titled
> 
>     clk: Respect CLK_OPS_PARENT_ENABLE during recalc
> 
> to the 6.19-stable tree which can be found at:
>     http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
> 
> The filename of the patch is:
>      clk-respect-clk_ops_parent_enable-during-recalc.patch
> and it can be found in the queue-6.19 subdirectory.
> 
> If you, or anyone else, feels it should not be added to the stable tree,
> please let <stable@vger.kernel.org> know about it.

Drop this, it introduces a regression and has been reverted in [1]

Link: https://lore.kernel.org/lkml/20260203002439.1223213-1-sboyd@kernel.org/ [1]

> 
> 
> 
> commit 17b0f85bf6339d9e275389fa4ba8c9d2014a1bb7
> Author: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
> Date:   Mon Dec 15 11:23:58 2025 +0100
> 
>     clk: Respect CLK_OPS_PARENT_ENABLE during recalc
>     
>     [ Upstream commit 669917676e93fca5ea3c66fc9539830312bec58e ]
>     
>     When CLK_OPS_PARENT_ENABLE was introduced, it guarded various clock
>     operations, such as setting the rate or switching parents. However,
>     another operation that can and often does touch actual hardware state is
>     recalc_rate, which may also be affected by such a dependency.
>     
>     Add parent enables/disables where the recalc_rate op is called directly.
>     
>     Fixes: fc8726a2c021 ("clk: core: support clocks which requires parents enable (part 2)")
>     Fixes: a4b3518d146f ("clk: core: support clocks which requires parents enable (part 1)")
>     Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
>     Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
>     Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
>     Signed-off-by: Stephen Boyd <sboyd@kernel.org>
>     Signed-off-by: Sasha Levin <sashal@kernel.org>
> 
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index 85d2f2481acf3..1b0f9d567f48e 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -1921,7 +1921,14 @@ static unsigned long clk_recalc(struct clk_core *core,
>  	unsigned long rate = parent_rate;
>  
>  	if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) {
> +		if (core->flags & CLK_OPS_PARENT_ENABLE)
> +			clk_core_prepare_enable(core->parent);
> +
>  		rate = core->ops->recalc_rate(core->hw, parent_rate);
> +
> +		if (core->flags & CLK_OPS_PARENT_ENABLE)
> +			clk_core_disable_unprepare(core->parent);
> +
>  		clk_pm_runtime_put(core);
>  	}
>  	return rate;
> @@ -4031,6 +4038,9 @@ static int __clk_core_init(struct clk_core *core)
>  	 */
>  	clk_core_update_duty_cycle_nolock(core);
>  
> +	if (core->flags & CLK_OPS_PARENT_ENABLE)
> +		clk_core_prepare_enable(core->parent);
> +
>  	/*
>  	 * Set clk's rate.  The preferred method is to use .recalc_rate.  For
>  	 * simple clocks and lazy developers the default fallback is to use the
> @@ -4046,6 +4056,9 @@ static int __clk_core_init(struct clk_core *core)
>  		rate = 0;
>  	core->rate = core->req_rate = rate;
>  
> +	if (core->flags & CLK_OPS_PARENT_ENABLE)
> +		clk_core_disable_unprepare(core->parent);
> +
>  	/*
>  	 * Enable CLK_IS_CRITICAL clocks so newly added critical clocks
>  	 * don't get accidentally disabled when walking the orphan tree and
>