i2c: i2c-qcom-geni: Fix suspend clock handling

Message ID 20180709234937.176154-1-evgreen@chromium.org
State Accepted
Headers show
Series
  • i2c: i2c-qcom-geni: Fix suspend clock handling
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Commit Message

Evan Green July 9, 2018, 11:49 p.m.
pm_runtime_suspended can return 0 even if the last runtime power
management function called in the device was a suspend call. This
trips up the i2c-qcom-geni's suspend_noirq accounting, which was
trying to use the function to determine if it should disable clocks
or if that had already been done.

The fix is to track whether or not clocks have been enabled explicitly
in the driver with a new member. While in there, also honor the return
value of geni_se_resources_off, which can technically fail.

An example of the warning generated during suspend:
[   68.314733] WARNING: CPU: 0 PID: 1990 at drivers/clk/clk.c:595 clk_core_disable+0x28/0x200
[   68.464576] Call trace:
[   68.554410] [<ffffff80083f0ed0>] clk_core_disable+0x28/0x200
[   68.560244] [<ffffff80083f349c>] clk_disable+0x38/0x4c
[   68.565541] [<ffffff8008408910>] geni_se_resources_off+0x40/0x74
[   68.571731] [<ffffff800862aadc>] geni_i2c_runtime_suspend+0x2c/0x3c
[   68.578185] [<ffffff800862ae6c>] geni_i2c_suspend_noirq+0x38/0x68
[   68.584475] [<ffffff800852bd40>] dpm_run_callback+0x104/0x210
[   68.590404] [<ffffff800852c3d4>] __device_suspend_noirq+0x158/0x1a8
[   68.596859] [<ffffff800852dff0>] dpm_noirq_suspend_devices+0x180/0x38c
[   68.603594] [<ffffff80080fdebc>] suspend_devices_and_enter+0x49c/0x964
[   68.610321] [<ffffff80080fea14>] pm_suspend+0x690/0x6e0
[   68.615712] [<ffffff80080fc930>] state_store+0xd4/0xf8
[   68.621014] [<ffffff80088a57f0>] kobj_attr_store+0x18/0x28
[   68.626672] [<ffffff8008297a54>] sysfs_kf_write+0x5c/0x68
[   68.632240] [<ffffff8008296a00>] kernfs_fop_write+0x174/0x1b8
[   68.638177] [<ffffff800821a2c4>] __vfs_write+0x58/0x160
[   68.643567] [<ffffff800821a5d8>] vfs_write+0xcc/0x184
[   68.648780] [<ffffff800821a850>] SyS_write+0x64/0xb4

Signed-off-by: Evan Green <evgreen@chromium.org>
---
This change applies atop Karthik's patch [1], which as far as I can tell
technically hasn't landed yet, but also hasn't had feedback in awhile
either. I opted to submit this as a separate patch, but if the maintainers
prefer it's fine with me if this get folded in to another spin of the
base series.

[1] https://patchwork.kernel.org/patch/10460819/

 drivers/i2c/busses/i2c-qcom-geni.c | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

Comments

Wolfram Sang July 12, 2018, 10:03 p.m. | #1
On Mon, Jul 09, 2018 at 04:49:37PM -0700, Evan Green wrote:
> pm_runtime_suspended can return 0 even if the last runtime power
> management function called in the device was a suspend call. This
> trips up the i2c-qcom-geni's suspend_noirq accounting, which was
> trying to use the function to determine if it should disable clocks
> or if that had already been done.
> 
> The fix is to track whether or not clocks have been enabled explicitly
> in the driver with a new member. While in there, also honor the return
> value of geni_se_resources_off, which can technically fail.
> 
> An example of the warning generated during suspend:
> [   68.314733] WARNING: CPU: 0 PID: 1990 at drivers/clk/clk.c:595 clk_core_disable+0x28/0x200
> [   68.464576] Call trace:
> [   68.554410] [<ffffff80083f0ed0>] clk_core_disable+0x28/0x200
> [   68.560244] [<ffffff80083f349c>] clk_disable+0x38/0x4c
> [   68.565541] [<ffffff8008408910>] geni_se_resources_off+0x40/0x74
> [   68.571731] [<ffffff800862aadc>] geni_i2c_runtime_suspend+0x2c/0x3c
> [   68.578185] [<ffffff800862ae6c>] geni_i2c_suspend_noirq+0x38/0x68
> [   68.584475] [<ffffff800852bd40>] dpm_run_callback+0x104/0x210
> [   68.590404] [<ffffff800852c3d4>] __device_suspend_noirq+0x158/0x1a8
> [   68.596859] [<ffffff800852dff0>] dpm_noirq_suspend_devices+0x180/0x38c
> [   68.603594] [<ffffff80080fdebc>] suspend_devices_and_enter+0x49c/0x964
> [   68.610321] [<ffffff80080fea14>] pm_suspend+0x690/0x6e0
> [   68.615712] [<ffffff80080fc930>] state_store+0xd4/0xf8
> [   68.621014] [<ffffff80088a57f0>] kobj_attr_store+0x18/0x28
> [   68.626672] [<ffffff8008297a54>] sysfs_kf_write+0x5c/0x68
> [   68.632240] [<ffffff8008296a00>] kernfs_fop_write+0x174/0x1b8
> [   68.638177] [<ffffff800821a2c4>] __vfs_write+0x58/0x160
> [   68.643567] [<ffffff800821a5d8>] vfs_write+0xcc/0x184
> [   68.648780] [<ffffff800821a850>] SyS_write+0x64/0xb4
> 
> Signed-off-by: Evan Green <evgreen@chromium.org>
> ---
> This change applies atop Karthik's patch [1], which as far as I can tell
> technically hasn't landed yet, but also hasn't had feedback in awhile
> either. I opted to submit this as a separate patch, but if the maintainers
> prefer it's fine with me if this get folded in to another spin of the
> base series.
> 
> [1] https://patchwork.kernel.org/patch/10460819/

Yeah, since the FSI driver seems to be mostly done now, this will be the
next new driver I will have a look at.

If the maintainers of the driver ack or rev this patch, I would then
just fold it into the driver itself when I apply it?

D'accord everyone?
Karthikeyan Ramasubramanian July 13, 2018, 10:21 p.m. | #2
On 7/9/2018 5:49 PM, Evan Green wrote:
> pm_runtime_suspended can return 0 even if the last runtime power
> management function called in the device was a suspend call. This
> trips up the i2c-qcom-geni's suspend_noirq accounting, which was
> trying to use the function to determine if it should disable clocks
> or if that had already been done.
> 
> The fix is to track whether or not clocks have been enabled explicitly
> in the driver with a new member. While in there, also honor the return
> value of geni_se_resources_off, which can technically fail.
> 
> An example of the warning generated during suspend:
> [   68.314733] WARNING: CPU: 0 PID: 1990 at drivers/clk/clk.c:595 clk_core_disable+0x28/0x200
> [   68.464576] Call trace:
> [   68.554410] [<ffffff80083f0ed0>] clk_core_disable+0x28/0x200
> [   68.560244] [<ffffff80083f349c>] clk_disable+0x38/0x4c
> [   68.565541] [<ffffff8008408910>] geni_se_resources_off+0x40/0x74
> [   68.571731] [<ffffff800862aadc>] geni_i2c_runtime_suspend+0x2c/0x3c
> [   68.578185] [<ffffff800862ae6c>] geni_i2c_suspend_noirq+0x38/0x68
> [   68.584475] [<ffffff800852bd40>] dpm_run_callback+0x104/0x210
> [   68.590404] [<ffffff800852c3d4>] __device_suspend_noirq+0x158/0x1a8
> [   68.596859] [<ffffff800852dff0>] dpm_noirq_suspend_devices+0x180/0x38c
> [   68.603594] [<ffffff80080fdebc>] suspend_devices_and_enter+0x49c/0x964
> [   68.610321] [<ffffff80080fea14>] pm_suspend+0x690/0x6e0
> [   68.615712] [<ffffff80080fc930>] state_store+0xd4/0xf8
> [   68.621014] [<ffffff80088a57f0>] kobj_attr_store+0x18/0x28
> [   68.626672] [<ffffff8008297a54>] sysfs_kf_write+0x5c/0x68
> [   68.632240] [<ffffff8008296a00>] kernfs_fop_write+0x174/0x1b8
> [   68.638177] [<ffffff800821a2c4>] __vfs_write+0x58/0x160
> [   68.643567] [<ffffff800821a5d8>] vfs_write+0xcc/0x184
> [   68.648780] [<ffffff800821a850>] SyS_write+0x64/0xb4
> 
> Signed-off-by: Evan Green <evgreen@chromium.org>
> ---
> This change applies atop Karthik's patch [1], which as far as I can tell
> technically hasn't landed yet, but also hasn't had feedback in awhile
> either. I opted to submit this as a separate patch, but if the maintainers
> prefer it's fine with me if this get folded in to another spin of the
> base series.
> 
> [1] https://patchwork.kernel.org/patch/10460819/
> 
>  drivers/i2c/busses/i2c-qcom-geni.c | 25 ++++++++++++++++++++++---
>  1 file changed, 22 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
> index 54bcd1a79cc5..90c4cbfa22d8 100644
> --- a/drivers/i2c/busses/i2c-qcom-geni.c
> +++ b/drivers/i2c/busses/i2c-qcom-geni.c
> @@ -85,6 +85,7 @@ struct geni_i2c_dev {
>  	spinlock_t lock;
>  	u32 clk_freq_out;
>  	const struct geni_i2c_clk_fld *clk_fld;
> +	int suspended;
>  };
>  
>  struct geni_i2c_err_log {
> @@ -567,9 +568,15 @@ static int geni_i2c_probe(struct platform_device *pdev)
>  	geni_se_init(&gi2c->se, gi2c->tx_wm, tx_depth);
>  	geni_se_config_packing(&gi2c->se, BITS_PER_BYTE, PACKING_BYTES_PW,
>  							true, true, true);
> -	geni_se_resources_off(&gi2c->se);
> +	ret = geni_se_resources_off(&gi2c->se);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Error turning off resources %d\n", ret);
> +		return ret;
> +	}
> +
>  	dev_dbg(&pdev->dev, "i2c fifo/se-dma mode. fifo depth:%d\n", tx_depth);
>  
> +	gi2c->suspended = 1;
>  	pm_runtime_set_suspended(gi2c->se.dev);
>  	pm_runtime_set_autosuspend_delay(gi2c->se.dev, I2C_AUTO_SUSPEND_DELAY);
>  	pm_runtime_use_autosuspend(gi2c->se.dev);
> @@ -590,10 +597,19 @@ static int geni_i2c_remove(struct platform_device *pdev)
>  
>  static int __maybe_unused geni_i2c_runtime_suspend(struct device *dev)
>  {
> +	int ret;
>  	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
>  
>  	disable_irq(gi2c->irq);
> -	geni_se_resources_off(&gi2c->se);
> +	ret = geni_se_resources_off(&gi2c->se);
> +	if (ret) {
> +		enable_irq(gi2c->irq);
> +		return ret;
> +
> +	} else {
> +		gi2c->suspended = 1;
> +	}
> +
>  	return 0;
>  }
>  
> @@ -607,12 +623,15 @@ static int __maybe_unused geni_i2c_runtime_resume(struct device *dev)
>  		return ret;
>  
>  	enable_irq(gi2c->irq);
> +	gi2c->suspended = 0;
>  	return 0;
>  }
>  
>  static int __maybe_unused geni_i2c_suspend_noirq(struct device *dev)
>  {
> -	if (!pm_runtime_suspended(dev)) {
> +	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
> +
> +	if (!gi2c->suspended) {
>  		geni_i2c_runtime_suspend(dev);
>  		pm_runtime_disable(dev);
>  		pm_runtime_set_suspended(dev);
> 
Reviewed-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>
Evan Green July 13, 2018, 10:24 p.m. | #3
On Fri, Jul 13, 2018 at 3:21 PM Karthik Ramasubramanian
<kramasub@codeaurora.org> wrote:
>
>
>
> On 7/9/2018 5:49 PM, Evan Green wrote:
> > pm_runtime_suspended can return 0 even if the last runtime power
> > management function called in the device was a suspend call. This
> > trips up the i2c-qcom-geni's suspend_noirq accounting, which was
> > trying to use the function to determine if it should disable clocks
> > or if that had already been done.
> >
> > The fix is to track whether or not clocks have been enabled explicitly
> > in the driver with a new member. While in there, also honor the return
> > value of geni_se_resources_off, which can technically fail.
> >
> > An example of the warning generated during suspend:
> > [   68.314733] WARNING: CPU: 0 PID: 1990 at drivers/clk/clk.c:595 clk_core_disable+0x28/0x200
> > [   68.464576] Call trace:
> > [   68.554410] [<ffffff80083f0ed0>] clk_core_disable+0x28/0x200
> > [   68.560244] [<ffffff80083f349c>] clk_disable+0x38/0x4c
> > [   68.565541] [<ffffff8008408910>] geni_se_resources_off+0x40/0x74
> > [   68.571731] [<ffffff800862aadc>] geni_i2c_runtime_suspend+0x2c/0x3c
> > [   68.578185] [<ffffff800862ae6c>] geni_i2c_suspend_noirq+0x38/0x68
> > [   68.584475] [<ffffff800852bd40>] dpm_run_callback+0x104/0x210
> > [   68.590404] [<ffffff800852c3d4>] __device_suspend_noirq+0x158/0x1a8
> > [   68.596859] [<ffffff800852dff0>] dpm_noirq_suspend_devices+0x180/0x38c
> > [   68.603594] [<ffffff80080fdebc>] suspend_devices_and_enter+0x49c/0x964
> > [   68.610321] [<ffffff80080fea14>] pm_suspend+0x690/0x6e0
> > [   68.615712] [<ffffff80080fc930>] state_store+0xd4/0xf8
> > [   68.621014] [<ffffff80088a57f0>] kobj_attr_store+0x18/0x28
> > [   68.626672] [<ffffff8008297a54>] sysfs_kf_write+0x5c/0x68
> > [   68.632240] [<ffffff8008296a00>] kernfs_fop_write+0x174/0x1b8
> > [   68.638177] [<ffffff800821a2c4>] __vfs_write+0x58/0x160
> > [   68.643567] [<ffffff800821a5d8>] vfs_write+0xcc/0x184
> > [   68.648780] [<ffffff800821a850>] SyS_write+0x64/0xb4
> >
> > Signed-off-by: Evan Green <evgreen@chromium.org>
> > ---
> > This change applies atop Karthik's patch [1], which as far as I can tell
> > technically hasn't landed yet, but also hasn't had feedback in awhile
> > either. I opted to submit this as a separate patch, but if the maintainers
> > prefer it's fine with me if this get folded in to another spin of the
> > base series.
> >
> > [1] https://patchwork.kernel.org/patch/10460819/
> >
> >  drivers/i2c/busses/i2c-qcom-geni.c | 25 ++++++++++++++++++++++---
> >  1 file changed, 22 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
> > index 54bcd1a79cc5..90c4cbfa22d8 100644
> > --- a/drivers/i2c/busses/i2c-qcom-geni.c
> > +++ b/drivers/i2c/busses/i2c-qcom-geni.c
> > @@ -85,6 +85,7 @@ struct geni_i2c_dev {
> >       spinlock_t lock;
> >       u32 clk_freq_out;
> >       const struct geni_i2c_clk_fld *clk_fld;
> > +     int suspended;
> >  };
> >
> >  struct geni_i2c_err_log {
> > @@ -567,9 +568,15 @@ static int geni_i2c_probe(struct platform_device *pdev)
> >       geni_se_init(&gi2c->se, gi2c->tx_wm, tx_depth);
> >       geni_se_config_packing(&gi2c->se, BITS_PER_BYTE, PACKING_BYTES_PW,
> >                                                       true, true, true);
> > -     geni_se_resources_off(&gi2c->se);
> > +     ret = geni_se_resources_off(&gi2c->se);
> > +     if (ret) {
> > +             dev_err(&pdev->dev, "Error turning off resources %d\n", ret);
> > +             return ret;
> > +     }
> > +
> >       dev_dbg(&pdev->dev, "i2c fifo/se-dma mode. fifo depth:%d\n", tx_depth);
> >
> > +     gi2c->suspended = 1;
> >       pm_runtime_set_suspended(gi2c->se.dev);
> >       pm_runtime_set_autosuspend_delay(gi2c->se.dev, I2C_AUTO_SUSPEND_DELAY);
> >       pm_runtime_use_autosuspend(gi2c->se.dev);
> > @@ -590,10 +597,19 @@ static int geni_i2c_remove(struct platform_device *pdev)
> >
> >  static int __maybe_unused geni_i2c_runtime_suspend(struct device *dev)
> >  {
> > +     int ret;
> >       struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
> >
> >       disable_irq(gi2c->irq);
> > -     geni_se_resources_off(&gi2c->se);
> > +     ret = geni_se_resources_off(&gi2c->se);
> > +     if (ret) {
> > +             enable_irq(gi2c->irq);
> > +             return ret;
> > +
> > +     } else {
> > +             gi2c->suspended = 1;
> > +     }
> > +
> >       return 0;
> >  }
> >
> > @@ -607,12 +623,15 @@ static int __maybe_unused geni_i2c_runtime_resume(struct device *dev)
> >               return ret;
> >
> >       enable_irq(gi2c->irq);
> > +     gi2c->suspended = 0;
> >       return 0;
> >  }
> >
> >  static int __maybe_unused geni_i2c_suspend_noirq(struct device *dev)
> >  {
> > -     if (!pm_runtime_suspended(dev)) {
> > +     struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
> > +
> > +     if (!gi2c->suspended) {
> >               geni_i2c_runtime_suspend(dev);
> >               pm_runtime_disable(dev);
> >               pm_runtime_set_suspended(dev);
> >
> Reviewed-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>

Sounds good to me, Wolfram. Thanks for the review, Karthik.
-Evan
Wolfram Sang July 31, 2018, 7:20 p.m. | #4
On Mon, Jul 09, 2018 at 04:49:37PM -0700, Evan Green wrote:
> pm_runtime_suspended can return 0 even if the last runtime power
> management function called in the device was a suspend call. This
> trips up the i2c-qcom-geni's suspend_noirq accounting, which was
> trying to use the function to determine if it should disable clocks
> or if that had already been done.
> 
> The fix is to track whether or not clocks have been enabled explicitly
> in the driver with a new member. While in there, also honor the return
> value of geni_se_resources_off, which can technically fail.
> 
> An example of the warning generated during suspend:
> [   68.314733] WARNING: CPU: 0 PID: 1990 at drivers/clk/clk.c:595 clk_core_disable+0x28/0x200
> [   68.464576] Call trace:
> [   68.554410] [<ffffff80083f0ed0>] clk_core_disable+0x28/0x200
> [   68.560244] [<ffffff80083f349c>] clk_disable+0x38/0x4c
> [   68.565541] [<ffffff8008408910>] geni_se_resources_off+0x40/0x74
> [   68.571731] [<ffffff800862aadc>] geni_i2c_runtime_suspend+0x2c/0x3c
> [   68.578185] [<ffffff800862ae6c>] geni_i2c_suspend_noirq+0x38/0x68
> [   68.584475] [<ffffff800852bd40>] dpm_run_callback+0x104/0x210
> [   68.590404] [<ffffff800852c3d4>] __device_suspend_noirq+0x158/0x1a8
> [   68.596859] [<ffffff800852dff0>] dpm_noirq_suspend_devices+0x180/0x38c
> [   68.603594] [<ffffff80080fdebc>] suspend_devices_and_enter+0x49c/0x964
> [   68.610321] [<ffffff80080fea14>] pm_suspend+0x690/0x6e0
> [   68.615712] [<ffffff80080fc930>] state_store+0xd4/0xf8
> [   68.621014] [<ffffff80088a57f0>] kobj_attr_store+0x18/0x28
> [   68.626672] [<ffffff8008297a54>] sysfs_kf_write+0x5c/0x68
> [   68.632240] [<ffffff8008296a00>] kernfs_fop_write+0x174/0x1b8
> [   68.638177] [<ffffff800821a2c4>] __vfs_write+0x58/0x160
> [   68.643567] [<ffffff800821a5d8>] vfs_write+0xcc/0x184
> [   68.648780] [<ffffff800821a850>] SyS_write+0x64/0xb4
> 
> Signed-off-by: Evan Green <evgreen@chromium.org>

Applied to for-next (squashed into the main driver), thanks!

Patch

diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
index 54bcd1a79cc5..90c4cbfa22d8 100644
--- a/drivers/i2c/busses/i2c-qcom-geni.c
+++ b/drivers/i2c/busses/i2c-qcom-geni.c
@@ -85,6 +85,7 @@  struct geni_i2c_dev {
 	spinlock_t lock;
 	u32 clk_freq_out;
 	const struct geni_i2c_clk_fld *clk_fld;
+	int suspended;
 };
 
 struct geni_i2c_err_log {
@@ -567,9 +568,15 @@  static int geni_i2c_probe(struct platform_device *pdev)
 	geni_se_init(&gi2c->se, gi2c->tx_wm, tx_depth);
 	geni_se_config_packing(&gi2c->se, BITS_PER_BYTE, PACKING_BYTES_PW,
 							true, true, true);
-	geni_se_resources_off(&gi2c->se);
+	ret = geni_se_resources_off(&gi2c->se);
+	if (ret) {
+		dev_err(&pdev->dev, "Error turning off resources %d\n", ret);
+		return ret;
+	}
+
 	dev_dbg(&pdev->dev, "i2c fifo/se-dma mode. fifo depth:%d\n", tx_depth);
 
+	gi2c->suspended = 1;
 	pm_runtime_set_suspended(gi2c->se.dev);
 	pm_runtime_set_autosuspend_delay(gi2c->se.dev, I2C_AUTO_SUSPEND_DELAY);
 	pm_runtime_use_autosuspend(gi2c->se.dev);
@@ -590,10 +597,19 @@  static int geni_i2c_remove(struct platform_device *pdev)
 
 static int __maybe_unused geni_i2c_runtime_suspend(struct device *dev)
 {
+	int ret;
 	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
 
 	disable_irq(gi2c->irq);
-	geni_se_resources_off(&gi2c->se);
+	ret = geni_se_resources_off(&gi2c->se);
+	if (ret) {
+		enable_irq(gi2c->irq);
+		return ret;
+
+	} else {
+		gi2c->suspended = 1;
+	}
+
 	return 0;
 }
 
@@ -607,12 +623,15 @@  static int __maybe_unused geni_i2c_runtime_resume(struct device *dev)
 		return ret;
 
 	enable_irq(gi2c->irq);
+	gi2c->suspended = 0;
 	return 0;
 }
 
 static int __maybe_unused geni_i2c_suspend_noirq(struct device *dev)
 {
-	if (!pm_runtime_suspended(dev)) {
+	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
+
+	if (!gi2c->suspended) {
 		geni_i2c_runtime_suspend(dev);
 		pm_runtime_disable(dev);
 		pm_runtime_set_suspended(dev);