Patchwork [v2,7/7] i2c-designware: switch to use runtime PM autosuspend

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Submitter Mika Westerberg
Date April 10, 2013, 10:36 a.m.
Message ID <1365590202-1623-7-git-send-email-mika.westerberg@linux.intel.com>
Download mbox | patch
Permalink /patch/235356/
State Accepted
Headers show

Comments

Mika Westerberg - April 10, 2013, 10:36 a.m.
Using autosuspend helps to reduce the resume latency in situations where
another I2C message is going to be started soon. For example with HID over
I2C touch panels we get several messages in a short period of time while
the touch panel is in use.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/i2c/busses/i2c-designware-core.c    |    3 ++-
 drivers/i2c/busses/i2c-designware-pcidrv.c  |    3 ++-
 drivers/i2c/busses/i2c-designware-platdrv.c |    3 ++-
 3 files changed, 6 insertions(+), 3 deletions(-)
Mika Westerberg - April 10, 2013, 11:56 a.m.
On Wed, Apr 10, 2013 at 05:13:57PM +0530, Shubhrajyoti Datta wrote:
> Hi Mika,
> 
> 
> 
> On Wed, Apr 10, 2013 at 4:06 PM, Mika Westerberg <
> mika.westerberg@linux.intel.com> wrote:
> 
> > Using autosuspend helps to reduce the resume latency in situations where
> > another I2C message is going to be started soon. For example with HID over
> > I2C touch panels we get several messages in a short period of time while
> > the touch panel is in use.
> >
> Also the time to autosuspend could  be a macro just in case someone wants
> to tweak it.
> 
> Just a suggestion.

Well, you can always do that via sysfs /sys/.../power/autosuspend_delay_ms
(or whatever the name of the file is).

> > Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
> > ---
> >  drivers/i2c/busses/i2c-designware-core.c    |    3 ++-
> >  drivers/i2c/busses/i2c-designware-pcidrv.c  |    3 ++-
> >  drivers/i2c/busses/i2c-designware-platdrv.c |    3 ++-
> >  3 files changed, 6 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/i2c/busses/i2c-designware-core.c
> > b/drivers/i2c/busses/i2c-designware-core.c
> > index 7c10c5b..21fbb34 100644
> > --- a/drivers/i2c/busses/i2c-designware-core.c
> > +++ b/drivers/i2c/busses/i2c-designware-core.c
> > @@ -600,7 +600,8 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg
> > msgs[], int num)
> >         ret = -EIO;
> >
> >  done:
> > -       pm_runtime_put(dev->dev);
> > +       pm_runtime_mark_last_busy(dev->dev);
> > +       pm_runtime_put_autosuspend(dev->dev);
> >         mutex_unlock(&dev->lock);
> >
> >         return ret;
> > diff --git a/drivers/i2c/busses/i2c-designware-pcidrv.c
> > b/drivers/i2c/busses/i2c-designware-pcidrv.c
> > index aacb64e..c8797e2 100644
> > --- a/drivers/i2c/busses/i2c-designware-pcidrv.c
> > +++ b/drivers/i2c/busses/i2c-designware-pcidrv.c
> > @@ -291,7 +291,8 @@ static int i2c_dw_pci_probe(struct pci_dev *pdev,
> >         /* Increase reference counter */
> >         get_device(&pdev->dev);
> >
> > -       pm_runtime_put_noidle(&pdev->dev);
> > +       pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
> > +       pm_runtime_use_autosuspend(&pdev->dev);
> >         pm_runtime_allow(&pdev->dev);
> >
> 
> Could you explain this?

Hmm, I'm not sure what you mean. In the above we enable autosuspend and set
the delay. Am I missing something?
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Patch

diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c
index 7c10c5b..21fbb34 100644
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -600,7 +600,8 @@  i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 	ret = -EIO;
 
 done:
-	pm_runtime_put(dev->dev);
+	pm_runtime_mark_last_busy(dev->dev);
+	pm_runtime_put_autosuspend(dev->dev);
 	mutex_unlock(&dev->lock);
 
 	return ret;
diff --git a/drivers/i2c/busses/i2c-designware-pcidrv.c b/drivers/i2c/busses/i2c-designware-pcidrv.c
index aacb64e..c8797e2 100644
--- a/drivers/i2c/busses/i2c-designware-pcidrv.c
+++ b/drivers/i2c/busses/i2c-designware-pcidrv.c
@@ -291,7 +291,8 @@  static int i2c_dw_pci_probe(struct pci_dev *pdev,
 	/* Increase reference counter */
 	get_device(&pdev->dev);
 
-	pm_runtime_put_noidle(&pdev->dev);
+	pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
+	pm_runtime_use_autosuspend(&pdev->dev);
 	pm_runtime_allow(&pdev->dev);
 
 	return 0;
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 0735ccf..b47c586 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -172,9 +172,10 @@  static int dw_i2c_probe(struct platform_device *pdev)
 	/* Increase reference counter */
 	get_device(&pdev->dev);
 
+	pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
+	pm_runtime_use_autosuspend(&pdev->dev);
 	pm_runtime_set_active(&pdev->dev);
 	pm_runtime_enable(&pdev->dev);
-	pm_runtime_put(&pdev->dev);
 
 	return 0;
 }