diff mbox

[4/7] serial: 8250_omap: Fix PM regression with deferred probe for pm_runtime_reinit

Message ID 1455145370-20301-5-git-send-email-tony@atomide.com (mailing list archive)
State New, archived
Headers show

Commit Message

Tony Lindgren Feb. 10, 2016, 11:02 p.m. UTC
Commit 5de85b9d57ab ("PM / runtime: Re-init runtime PM states at probe
error and driver unbind") introduced pm_runtime_reinit() that is used
to reinitialize PM runtime after -EPROBE_DEFER. This allows shutting
down the device after a failed probe.

However, for drivers using pm_runtime_use_autosuspend() this can cause
a state where suspend callback is never called after -EPROBE_DEFER.
On the following device driver probe, hardware state is different from
the PM runtime state causing omap_device to produce the following
error:

omap_device_enable() called from invalid state 1

And with omap_device and omap hardware being picky for PM, this will
block any deeper idle states in hardware.

The solution is to fix the drivers to follow the PM runtime documentation:

1. For sections of code that needs the device disabled, use
   pm_runtime_put_sync_suspend() if pm_runtime_set_autosuspend() has
   been set.

2. For driver exit code, use pm_runtime_dont_use_autosuspend() before
   pm_runtime_put_sync() if pm_runtime_use_autosuspend() has been
   set.

Fixes: 5de85b9d57ab ("PM / runtime: Re-init runtime PM states at probe
error and driver unbind")
Cc: linux-serial@vger.kernel.org
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Nishanth Menon <nm@ti.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---

Greg & Peter, I'd like to merge this along with other related fixes
via the ARM SoC tree if no objections, please review and ack if this
look OK to you.

---
 drivers/tty/serial/8250/8250_omap.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Greg KH Feb. 12, 2016, 3:17 a.m. UTC | #1
On Wed, Feb 10, 2016 at 03:02:47PM -0800, Tony Lindgren wrote:
> Commit 5de85b9d57ab ("PM / runtime: Re-init runtime PM states at probe
> error and driver unbind") introduced pm_runtime_reinit() that is used
> to reinitialize PM runtime after -EPROBE_DEFER. This allows shutting
> down the device after a failed probe.
> 
> However, for drivers using pm_runtime_use_autosuspend() this can cause
> a state where suspend callback is never called after -EPROBE_DEFER.
> On the following device driver probe, hardware state is different from
> the PM runtime state causing omap_device to produce the following
> error:
> 
> omap_device_enable() called from invalid state 1
> 
> And with omap_device and omap hardware being picky for PM, this will
> block any deeper idle states in hardware.
> 
> The solution is to fix the drivers to follow the PM runtime documentation:
> 
> 1. For sections of code that needs the device disabled, use
>    pm_runtime_put_sync_suspend() if pm_runtime_set_autosuspend() has
>    been set.
> 
> 2. For driver exit code, use pm_runtime_dont_use_autosuspend() before
>    pm_runtime_put_sync() if pm_runtime_use_autosuspend() has been
>    set.
> 
> Fixes: 5de85b9d57ab ("PM / runtime: Re-init runtime PM states at probe
> error and driver unbind")
> Cc: linux-serial@vger.kernel.org
> Cc: Alan Stern <stern@rowland.harvard.edu>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Kevin Hilman <khilman@baylibre.com>
> Cc: Nishanth Menon <nm@ti.com>
> Cc: Peter Hurley <peter@hurleysoftware.com>
> Cc: Rafael J. Wysocki <rafael@kernel.org>
> Cc: Ulf Hansson <ulf.hansson@linaro.org>
> Cc: Tero Kristo <t-kristo@ti.com>
> Signed-off-by: Tony Lindgren <tony@atomide.com>
> ---
> 
> Greg & Peter, I'd like to merge this along with other related fixes
> via the ARM SoC tree if no objections, please review and ack if this
> look OK to you.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Ulf Hansson Feb. 12, 2016, 12:52 p.m. UTC | #2
On 11 February 2016 at 00:02, Tony Lindgren <tony@atomide.com> wrote:
> Commit 5de85b9d57ab ("PM / runtime: Re-init runtime PM states at probe
> error and driver unbind") introduced pm_runtime_reinit() that is used
> to reinitialize PM runtime after -EPROBE_DEFER. This allows shutting
> down the device after a failed probe.
>
> However, for drivers using pm_runtime_use_autosuspend() this can cause
> a state where suspend callback is never called after -EPROBE_DEFER.
> On the following device driver probe, hardware state is different from
> the PM runtime state causing omap_device to produce the following
> error:
>
> omap_device_enable() called from invalid state 1
>
> And with omap_device and omap hardware being picky for PM, this will
> block any deeper idle states in hardware.
>
> The solution is to fix the drivers to follow the PM runtime documentation:
>
> 1. For sections of code that needs the device disabled, use
>    pm_runtime_put_sync_suspend() if pm_runtime_set_autosuspend() has
>    been set.
>
> 2. For driver exit code, use pm_runtime_dont_use_autosuspend() before
>    pm_runtime_put_sync() if pm_runtime_use_autosuspend() has been
>    set.
>
> Fixes: 5de85b9d57ab ("PM / runtime: Re-init runtime PM states at probe
> error and driver unbind")
> Cc: linux-serial@vger.kernel.org
> Cc: Alan Stern <stern@rowland.harvard.edu>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Kevin Hilman <khilman@baylibre.com>
> Cc: Nishanth Menon <nm@ti.com>
> Cc: Peter Hurley <peter@hurleysoftware.com>
> Cc: Rafael J. Wysocki <rafael@kernel.org>
> Cc: Ulf Hansson <ulf.hansson@linaro.org>
> Cc: Tero Kristo <t-kristo@ti.com>
> Signed-off-by: Tony Lindgren <tony@atomide.com>

Acked-by: Ulf Hansson <ulf.hansson@linaro.org>

Kind regards
Uffe

> ---
>
> Greg & Peter, I'd like to merge this along with other related fixes
> via the ARM SoC tree if no objections, please review and ack if this
> look OK to you.
>
> ---
>  drivers/tty/serial/8250/8250_omap.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
> index a2c0734..81ff337 100644
> --- a/drivers/tty/serial/8250/8250_omap.c
> +++ b/drivers/tty/serial/8250/8250_omap.c
> @@ -1235,7 +1235,8 @@ static int omap8250_probe(struct platform_device *pdev)
>         pm_runtime_put_autosuspend(&pdev->dev);
>         return 0;
>  err:
> -       pm_runtime_put(&pdev->dev);
> +       pm_runtime_dont_use_autosuspend(&pdev->dev);
> +       pm_runtime_put_sync(&pdev->dev);
>         pm_runtime_disable(&pdev->dev);
>         return ret;
>  }
> @@ -1244,6 +1245,7 @@ static int omap8250_remove(struct platform_device *pdev)
>  {
>         struct omap8250_priv *priv = platform_get_drvdata(pdev);
>
> +       pm_runtime_dont_use_autosuspend(&pdev->dev);
>         pm_runtime_put_sync(&pdev->dev);
>         pm_runtime_disable(&pdev->dev);
>         serial8250_unregister_port(priv->line);
> --
> 2.7.0
>
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diff mbox

Patch

diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index a2c0734..81ff337 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -1235,7 +1235,8 @@  static int omap8250_probe(struct platform_device *pdev)
 	pm_runtime_put_autosuspend(&pdev->dev);
 	return 0;
 err:
-	pm_runtime_put(&pdev->dev);
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
+	pm_runtime_put_sync(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	return ret;
 }
@@ -1244,6 +1245,7 @@  static int omap8250_remove(struct platform_device *pdev)
 {
 	struct omap8250_priv *priv = platform_get_drvdata(pdev);
 
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
 	pm_runtime_put_sync(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	serial8250_unregister_port(priv->line);