diff mbox

[2/7] i2c: omap: Fix PM regression with deferred probe for pm_runtime_reinit

Message ID 1455145370-20301-3-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-i2c@vger.kernel.org
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Nishanth Menon <nm@ti.com>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Tero Kristo <t-kristo@ti.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---

Wolfram, 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/i2c/busses/i2c-omap.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Wolfram Sang Feb. 11, 2016, 5:34 p.m. UTC | #1
> Wolfram, 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.

Well, since most patches seem to be picked up individually now, I'd
prefer to do the same. This is v4.5 material, or?
Tony Lindgren Feb. 11, 2016, 5:56 p.m. UTC | #2
* Wolfram Sang <wsa@the-dreams.de> [160211 09:35]:
> 
> > Wolfram, 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.
> 
> Well, since most patches seem to be picked up individually now, I'd
> prefer to do the same. This is v4.5 material, or?

Sure please do, thanks. And yes for v4.5 please. Although
I've only seen this happen with the MMC driver so far, there's
still a slight chance of this happening with the other drivers
using omap_device.

Regards,

Tony


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Ulf Hansson Feb. 12, 2016, 12:50 p.m. UTC | #3
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-i2c@vger.kernel.org
> Cc: Alan Stern <stern@rowland.harvard.edu>
> Cc: Kevin Hilman <khilman@baylibre.com>
> Cc: Nishanth Menon <nm@ti.com>
> Cc: Rafael J. Wysocki <rafael@kernel.org>
> Cc: Ulf Hansson <ulf.hansson@linaro.org>
> Cc: Tero Kristo <t-kristo@ti.com>
> Cc: Wolfram Sang <wsa@the-dreams.de>
> Signed-off-by: Tony Lindgren <tony@atomide.com>

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

Kind regards
Uffe

> ---
>
> Wolfram, 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/i2c/busses/i2c-omap.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
> index 08d26ba..13c4529 100644
> --- a/drivers/i2c/busses/i2c-omap.c
> +++ b/drivers/i2c/busses/i2c-omap.c
> @@ -1450,7 +1450,8 @@ omap_i2c_probe(struct platform_device *pdev)
>
>  err_unuse_clocks:
>         omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0);
> -       pm_runtime_put(omap->dev);
> +       pm_runtime_dont_use_autosuspend(omap->dev);
> +       pm_runtime_put_sync(omap->dev);
>         pm_runtime_disable(&pdev->dev);
>  err_free_mem:
>
> @@ -1468,6 +1469,7 @@ static int omap_i2c_remove(struct platform_device *pdev)
>                 return ret;
>
>         omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0);
> +       pm_runtime_dont_use_autosuspend(&pdev->dev);
>         pm_runtime_put_sync(&pdev->dev);
>         pm_runtime_disable(&pdev->dev);
>         return 0;
> --
> 2.7.0
>
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Wolfram Sang Feb. 12, 2016, 6:43 p.m. UTC | #4
On Wed, Feb 10, 2016 at 03:02:45PM -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-i2c@vger.kernel.org
> Cc: Alan Stern <stern@rowland.harvard.edu>
> Cc: Kevin Hilman <khilman@baylibre.com>
> Cc: Nishanth Menon <nm@ti.com>
> Cc: Rafael J. Wysocki <rafael@kernel.org>
> Cc: Ulf Hansson <ulf.hansson@linaro.org>
> Cc: Tero Kristo <t-kristo@ti.com>
> Cc: Wolfram Sang <wsa@the-dreams.de>
> Signed-off-by: Tony Lindgren <tony@atomide.com>

Applied to for-current, thanks!
diff mbox

Patch

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 08d26ba..13c4529 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -1450,7 +1450,8 @@  omap_i2c_probe(struct platform_device *pdev)
 
 err_unuse_clocks:
 	omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0);
-	pm_runtime_put(omap->dev);
+	pm_runtime_dont_use_autosuspend(omap->dev);
+	pm_runtime_put_sync(omap->dev);
 	pm_runtime_disable(&pdev->dev);
 err_free_mem:
 
@@ -1468,6 +1469,7 @@  static int omap_i2c_remove(struct platform_device *pdev)
 		return ret;
 
 	omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0);
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
 	pm_runtime_put_sync(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	return 0;