From: Stephen Boyd Date: Wed, 28 Jan 2026 19:01:34 +0000 (-0800) Subject: Revert "clk: Respect CLK_OPS_PARENT_ENABLE during recalc" X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=448b50b5cf12b7df254cae1d7ba3746e1acfc683;p=thirdparty%2Flinux.git Revert "clk: Respect CLK_OPS_PARENT_ENABLE during recalc" This reverts commit 669917676e93fca5ea3c66fc9539830312bec58e. It's been shown to cause problems on i.MX and STM32 platforms where the board doesn't boot. In one case, a clk with CLK_IS_CRITICAL and CLK_OPS_PARENT_ENABLE is being registered causing the parent to be enabled, the rate recalculated, and then the parent is disabled causing the critical clk being registered to stop clocking. A fix for that would be to calculate the rate of the clk after enabling the critical clk itself, but that wouldn't fix another problem where a clk with CLK_OPS_PARENT_ENABLE is registered before the parent is registered. In this case the hardware access in the clk_ops::recalc_rate() function would fail if the parent is disabled. There are even more problems exposed by this patch because it introduces logic that disables clks earlier in system boot than has existed previously. Historically we've not disabled clks until late init (clk_disable_unused) under the assumption that clks have been registered enough to have a consistent view of the clk tree. The clk_disable_unused logic doesn't work very well though, leading to quite a few devices booting with clk_ignore_unused on the kernel command line. Long story short, disabling clks during clk registration is full of pitfalls. Revert this commit until a proper solution can be found. Reported-by: Alexander Stein Closes: https://lore.kernel.org/r/6239343.lOV4Wx5bFT@steina-w Reported-by: Mark Brown Closes: https://lore.kernel.org/r/036da7ce-6487-4a6e-9b15-97c6d3bcdcec@sirena.org.uk Cc: Nicolas Frattaroli Cc: Brian Masney Cc: AngeloGioacchino Del Regno Cc: Chen-Yu Tsai Tested-by: Peng Fan Tested-by: Alexander Stein Reviewed-by: Brian Masney Tested-by: Mark Brown Signed-off-by: Stephen Boyd --- diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 1b0f9d567f48..85d2f2481acf 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1921,14 +1921,7 @@ 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; @@ -4038,9 +4031,6 @@ 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 @@ -4056,9 +4046,6 @@ 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