[2/3] clk: qcom: lpass-sc7180: Fix pm_runtime usage

Message ID 20221104064055.2.I49b25b9bda9430fc7ea21e5a708ca5a0aced2798@changeid
State New
Headers
Series [1/3] clk: qcom: lpass-sc7280: Fix pm_runtime usage |

Commit Message

Doug Anderson Nov. 4, 2022, 1:56 p.m. UTC
  The sc7180 lpass clock controller's pm_runtime usage wasn't broken
quite as spectacularly as the sc7280's pm_runtime usage, but it was
still broken. Putting some printouts in at boot showed me this (with
serial console enabled, which makes the prints slow and thus changes
timing):
  [    3.109951] DOUG: my_pm_clk_resume, usage=1
  [    3.114767] DOUG: my_pm_clk_resume, usage=1
  [    3.664443] DOUG: my_pm_clk_suspend, usage=0
  [    3.897566] DOUG: my_pm_clk_suspend, usage=0
  [    3.910137] DOUG: my_pm_clk_resume, usage=1
  [    3.923217] DOUG: my_pm_clk_resume, usage=0
  [    4.440116] DOUG: my_pm_clk_suspend, usage=-1
  [    4.444982] DOUG: my_pm_clk_suspend, usage=0
  [   14.170501] DOUG: my_pm_clk_resume, usage=1
  [   14.176245] DOUG: my_pm_clk_resume, usage=0

...or this w/out serial console:
  [    0.556139] DOUG: my_pm_clk_resume, usage=1
  [    0.556279] DOUG: my_pm_clk_resume, usage=1
  [    1.058422] DOUG: my_pm_clk_suspend, usage=-1
  [    1.058464] DOUG: my_pm_clk_suspend, usage=0
  [    1.186250] DOUG: my_pm_clk_resume, usage=1
  [    1.186292] DOUG: my_pm_clk_resume, usage=0
  [    1.731536] DOUG: my_pm_clk_suspend, usage=-1
  [    1.731557] DOUG: my_pm_clk_suspend, usage=0
  [   10.288910] DOUG: my_pm_clk_resume, usage=1
  [   10.289496] DOUG: my_pm_clk_resume, usage=0

It seems to be doing roughly the right sequence of calls, but just
like with sc7280 this is more by luck than anything. Having a usage of
-1 is just not OK.

Let's fix this like we did with sc7280.

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

 drivers/clk/qcom/lpasscorecc-sc7180.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)
  

Comments

Stephen Boyd Nov. 4, 2022, 9:19 p.m. UTC | #1
Quoting Douglas Anderson (2022-11-04 06:56:29)
> The sc7180 lpass clock controller's pm_runtime usage wasn't broken
> quite as spectacularly as the sc7280's pm_runtime usage, but it was
> still broken. Putting some printouts in at boot showed me this (with
> serial console enabled, which makes the prints slow and thus changes
> timing):
>   [    3.109951] DOUG: my_pm_clk_resume, usage=1
>   [    3.114767] DOUG: my_pm_clk_resume, usage=1
>   [    3.664443] DOUG: my_pm_clk_suspend, usage=0
>   [    3.897566] DOUG: my_pm_clk_suspend, usage=0
>   [    3.910137] DOUG: my_pm_clk_resume, usage=1
>   [    3.923217] DOUG: my_pm_clk_resume, usage=0
>   [    4.440116] DOUG: my_pm_clk_suspend, usage=-1
>   [    4.444982] DOUG: my_pm_clk_suspend, usage=0
>   [   14.170501] DOUG: my_pm_clk_resume, usage=1
>   [   14.176245] DOUG: my_pm_clk_resume, usage=0
>
> ...or this w/out serial console:
>   [    0.556139] DOUG: my_pm_clk_resume, usage=1
>   [    0.556279] DOUG: my_pm_clk_resume, usage=1
>   [    1.058422] DOUG: my_pm_clk_suspend, usage=-1
>   [    1.058464] DOUG: my_pm_clk_suspend, usage=0
>   [    1.186250] DOUG: my_pm_clk_resume, usage=1
>   [    1.186292] DOUG: my_pm_clk_resume, usage=0
>   [    1.731536] DOUG: my_pm_clk_suspend, usage=-1
>   [    1.731557] DOUG: my_pm_clk_suspend, usage=0
>   [   10.288910] DOUG: my_pm_clk_resume, usage=1
>   [   10.289496] DOUG: my_pm_clk_resume, usage=0
>
> It seems to be doing roughly the right sequence of calls, but just
> like with sc7280 this is more by luck than anything. Having a usage of
> -1 is just not OK.
>
> Let's fix this like we did with sc7280.

Any Fixes tag?

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

Reviewed-by: Stephen Boyd <swboyd@chromium.org>
  
Doug Anderson Nov. 4, 2022, 10:08 p.m. UTC | #2
Hi,

On Fri, Nov 4, 2022 at 2:19 PM Stephen Boyd <swboyd@chromium.org> wrote:
>
> Quoting Douglas Anderson (2022-11-04 06:56:29)
> > The sc7180 lpass clock controller's pm_runtime usage wasn't broken
> > quite as spectacularly as the sc7280's pm_runtime usage, but it was
> > still broken. Putting some printouts in at boot showed me this (with
> > serial console enabled, which makes the prints slow and thus changes
> > timing):
> >   [    3.109951] DOUG: my_pm_clk_resume, usage=1
> >   [    3.114767] DOUG: my_pm_clk_resume, usage=1
> >   [    3.664443] DOUG: my_pm_clk_suspend, usage=0
> >   [    3.897566] DOUG: my_pm_clk_suspend, usage=0
> >   [    3.910137] DOUG: my_pm_clk_resume, usage=1
> >   [    3.923217] DOUG: my_pm_clk_resume, usage=0
> >   [    4.440116] DOUG: my_pm_clk_suspend, usage=-1
> >   [    4.444982] DOUG: my_pm_clk_suspend, usage=0
> >   [   14.170501] DOUG: my_pm_clk_resume, usage=1
> >   [   14.176245] DOUG: my_pm_clk_resume, usage=0
> >
> > ...or this w/out serial console:
> >   [    0.556139] DOUG: my_pm_clk_resume, usage=1
> >   [    0.556279] DOUG: my_pm_clk_resume, usage=1
> >   [    1.058422] DOUG: my_pm_clk_suspend, usage=-1
> >   [    1.058464] DOUG: my_pm_clk_suspend, usage=0
> >   [    1.186250] DOUG: my_pm_clk_resume, usage=1
> >   [    1.186292] DOUG: my_pm_clk_resume, usage=0
> >   [    1.731536] DOUG: my_pm_clk_suspend, usage=-1
> >   [    1.731557] DOUG: my_pm_clk_suspend, usage=0
> >   [   10.288910] DOUG: my_pm_clk_resume, usage=1
> >   [   10.289496] DOUG: my_pm_clk_resume, usage=0
> >
> > It seems to be doing roughly the right sequence of calls, but just
> > like with sc7280 this is more by luck than anything. Having a usage of
> > -1 is just not OK.
> >
> > Let's fix this like we did with sc7280.
>
> Any Fixes tag?

Ah, right. I guess the most obvious one is actually:

Fixes: ce8c195e652f ("clk: qcom: lpasscc: Introduce pm autosuspend for SC7180")

That's what got us going negative. One could _sorta_ make the argument
for a "Fixes" tag all the way to the start of the driver, though. The
driver never did a pm_runtime_get() during probe and so there was (I
guess) a chance that some of the bare register writes in probe could
have been unclocked. I'm not aware of that ever being a problem, so I
guess just the above "Fixes" is fine.


> > Signed-off-by: Douglas Anderson <dianders@chromium.org>
> > ---
>
> Reviewed-by: Stephen Boyd <swboyd@chromium.org>

Thanks! Yell if you want me to spin a v2 with the Fixes in place.

-Doug
  

Patch

diff --git a/drivers/clk/qcom/lpasscorecc-sc7180.c b/drivers/clk/qcom/lpasscorecc-sc7180.c
index ac09b7b840ab..a5731994cbed 100644
--- a/drivers/clk/qcom/lpasscorecc-sc7180.c
+++ b/drivers/clk/qcom/lpasscorecc-sc7180.c
@@ -356,7 +356,7 @@  static const struct qcom_cc_desc lpass_audio_hm_sc7180_desc = {
 	.num_gdscs = ARRAY_SIZE(lpass_audio_hm_sc7180_gdscs),
 };
 
-static int lpass_create_pm_clks(struct platform_device *pdev)
+static int lpass_setup_runtime_pm(struct platform_device *pdev)
 {
 	int ret;
 
@@ -375,7 +375,7 @@  static int lpass_create_pm_clks(struct platform_device *pdev)
 	if (ret < 0)
 		dev_err(&pdev->dev, "failed to acquire iface clock\n");
 
-	return ret;
+	return pm_runtime_resume_and_get(&pdev->dev);
 }
 
 static int lpass_core_cc_sc7180_probe(struct platform_device *pdev)
@@ -384,7 +384,7 @@  static int lpass_core_cc_sc7180_probe(struct platform_device *pdev)
 	struct regmap *regmap;
 	int ret;
 
-	ret = lpass_create_pm_clks(pdev);
+	ret = lpass_setup_runtime_pm(pdev);
 	if (ret)
 		return ret;
 
@@ -392,12 +392,14 @@  static int lpass_core_cc_sc7180_probe(struct platform_device *pdev)
 	desc = &lpass_audio_hm_sc7180_desc;
 	ret = qcom_cc_probe_by_index(pdev, 1, desc);
 	if (ret)
-		return ret;
+		goto exit;
 
 	lpass_core_cc_sc7180_regmap_config.name = "lpass_core_cc";
 	regmap = qcom_cc_map(pdev, &lpass_core_cc_sc7180_desc);
-	if (IS_ERR(regmap))
-		return PTR_ERR(regmap);
+	if (IS_ERR(regmap)) {
+		ret = PTR_ERR(regmap);
+		goto exit;
+	}
 
 	/*
 	 * Keep the CLK always-ON
@@ -415,6 +417,7 @@  static int lpass_core_cc_sc7180_probe(struct platform_device *pdev)
 	ret = qcom_cc_really_probe(pdev, &lpass_core_cc_sc7180_desc, regmap);
 
 	pm_runtime_mark_last_busy(&pdev->dev);
+exit:
 	pm_runtime_put_autosuspend(&pdev->dev);
 
 	return ret;
@@ -425,14 +428,19 @@  static int lpass_hm_core_probe(struct platform_device *pdev)
 	const struct qcom_cc_desc *desc;
 	int ret;
 
-	ret = lpass_create_pm_clks(pdev);
+	ret = lpass_setup_runtime_pm(pdev);
 	if (ret)
 		return ret;
 
 	lpass_core_cc_sc7180_regmap_config.name = "lpass_hm_core";
 	desc = &lpass_core_hm_sc7180_desc;
 
-	return qcom_cc_probe_by_index(pdev, 0, desc);
+	ret = qcom_cc_probe_by_index(pdev, 0, desc);
+
+	pm_runtime_mark_last_busy(&pdev->dev);
+	pm_runtime_put_autosuspend(&pdev->dev);
+
+	return ret;
 }
 
 static const struct of_device_id lpass_hm_sc7180_match_table[] = {