Similar to the previous commit, we should make sure that all devices are
runtime resumed before printing the clk_summary through debugfs. Failure
to do so would result in a deadlock if the thread is resuming a device
to print clk state and that device is also runtime resuming in another
thread, e.g the screen is turning on and the display driver is starting
up.

Fixes: 1bb294a7981c ("clk: Enable/Disable runtime PM for clk_summary")
Cc: Taniya Das <quic_tdas@quicinc.com>
Cc: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
---
 drivers/clk/clk.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 31998ca67b1e..10792599bec1 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -3332,7 +3332,7 @@ static int clk_summary_show(struct seq_file *s, void *data)
 	seq_puts(s, "   clock                          count    count    count        rate   accuracy phase  cycle    enable   consumer                         id\n");
 	seq_puts(s, "---------------------------------------------------------------------------------------------------------------------------------------------\n");
 
-
+	clk_pm_runtime_get_all();
 	clk_prepare_lock();
 
 	for (; *lists; lists++)
@@ -3340,6 +3340,7 @@ static int clk_summary_show(struct seq_file *s, void *data)
 			clk_summary_show_subtree(s, c, 0);
 
 	clk_prepare_unlock();
+	clk_pm_runtime_put_all();
 
 	return 0;
 }
@@ -3389,6 +3390,8 @@ static int clk_dump_show(struct seq_file *s, void *data)
 	struct hlist_head **lists = s->private;
 
 	seq_putc(s, '{');
+
+	clk_pm_runtime_get_all();
 	clk_prepare_lock();
 
 	for (; *lists; lists++) {
@@ -3401,6 +3404,7 @@ static int clk_dump_show(struct seq_file *s, void *data)
 	}
 
 	clk_prepare_unlock();
+	clk_pm_runtime_put_all();
 
 	seq_puts(s, "}\n");
 	return 0;
-- 
https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git/
https://git.kernel.org/pub/scm/linux/kernel/git/sboyd/spmi.git

Hi,

On Sun, Mar 24, 2024 at 10:44 PM Stephen Boyd <sboyd@kernel.org> wrote:
>
> Similar to the previous commit, we should make sure that all devices are
> runtime resumed before printing the clk_summary through debugfs. Failure
> to do so would result in a deadlock if the thread is resuming a device
> to print clk state and that device is also runtime resuming in another
> thread, e.g the screen is turning on and the display driver is starting
> up.
>
> Fixes: 1bb294a7981c ("clk: Enable/Disable runtime PM for clk_summary")
> Cc: Taniya Das <quic_tdas@quicinc.com>
> Cc: Douglas Anderson <dianders@chromium.org>
> Signed-off-by: Stephen Boyd <sboyd@kernel.org>
> ---
>  drivers/clk/clk.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)

Shouldn't this also squash in a revert of commit 1bb294a7981c ("clk:
Enable/Disable runtime PM for clk_summary")? As it is,
clk_summary_show_subtree() is left with an extra/unnecessary
clk_pm_runtime_get() / clk_pm_runtime_put(), right?

Other than that, this looks good to me:

Reviewed-by: Douglas Anderson <dianders@chromium.org>

Quoting Doug Anderson (2024-03-25 09:19:51)
> Hi,
> 
> On Sun, Mar 24, 2024 at 10:44 PM Stephen Boyd <sboyd@kernel.org> wrote:
> >
> > Similar to the previous commit, we should make sure that all devices are
> > runtime resumed before printing the clk_summary through debugfs. Failure
> > to do so would result in a deadlock if the thread is resuming a device
> > to print clk state and that device is also runtime resuming in another
> > thread, e.g the screen is turning on and the display driver is starting
> > up.
> >
> > Fixes: 1bb294a7981c ("clk: Enable/Disable runtime PM for clk_summary")
> > Cc: Taniya Das <quic_tdas@quicinc.com>
> > Cc: Douglas Anderson <dianders@chromium.org>
> > Signed-off-by: Stephen Boyd <sboyd@kernel.org>
> > ---
> >  drivers/clk/clk.c | 6 +++++-
> >  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> Shouldn't this also squash in a revert of commit 1bb294a7981c ("clk:
> Enable/Disable runtime PM for clk_summary")? As it is,
> clk_summary_show_subtree() is left with an extra/unnecessary
> clk_pm_runtime_get() / clk_pm_runtime_put(), right?

Sure, it is superfluous now. I suppose it means we can remove
clk_pm_runtime_get()/put() calls in
clk_{disable,unprepare}_unused_subtree() as well.

> 
> Other than that, this looks good to me:
> 
> Reviewed-by: Douglas Anderson <dianders@chromium.org>