| Message ID | 20240325054403.592298-3-sboyd@kernel.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Fix a deadlock with clk_pm_runtime_get() | expand |
Hi, On Sun, Mar 24, 2024 at 10:44 PM Stephen Boyd <sboyd@kernel.org> wrote: > > We don't need to hold the prepare_lock when dropping a ref on a struct > clk_core. The release function is only freeing memory and any code with > a pointer reference has already unlinked anything pointing to the > clk_core. This reduces the holding area of the prepare_lock a bit. > > Note that we also don't call free_clk() with the prepare_lock held. > There isn't any reason to do that. > > Cc: Douglas Anderson <dianders@chromium.org> > Signed-off-by: Stephen Boyd <sboyd@kernel.org> > --- > drivers/clk/clk.c | 12 +++++------- > 1 file changed, 5 insertions(+), 7 deletions(-) Reviewed-by: Douglas Anderson <dianders@chromium.org>
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 44e71736477d..9fc522c26de8 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -4448,7 +4448,8 @@ void clk_unregister(struct clk *clk) if (ops == &clk_nodrv_ops) { pr_err("%s: unregistered clock: %s\n", __func__, clk->core->name); - goto unlock; + clk_prepare_unlock(); + return; } /* * Assign empty clock ops for consumers that might still hold @@ -4482,11 +4483,10 @@ void clk_unregister(struct clk *clk) if (clk->core->protect_count) pr_warn("%s: unregistering protected clock: %s\n", __func__, clk->core->name); + clk_prepare_unlock(); kref_put(&clk->core->ref, __clk_release); free_clk(clk); -unlock: - clk_prepare_unlock(); } EXPORT_SYMBOL_GPL(clk_unregister); @@ -4645,13 +4645,11 @@ void __clk_put(struct clk *clk) if (clk->min_rate > 0 || clk->max_rate < ULONG_MAX) clk_set_rate_range_nolock(clk, 0, ULONG_MAX); - owner = clk->core->owner; - kref_put(&clk->core->ref, __clk_release); - clk_prepare_unlock(); + owner = clk->core->owner; + kref_put(&clk->core->ref, __clk_release); module_put(owner); - free_clk(clk); }
We don't need to hold the prepare_lock when dropping a ref on a struct clk_core. The release function is only freeing memory and any code with a pointer reference has already unlinked anything pointing to the clk_core. This reduces the holding area of the prepare_lock a bit. Note that we also don't call free_clk() with the prepare_lock held. There isn't any reason to do that. Cc: Douglas Anderson <dianders@chromium.org> Signed-off-by: Stephen Boyd <sboyd@kernel.org> --- drivers/clk/clk.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-)