pm_runtime_get_sync() function fails during PM early resume and returning
-EACCES because runtime PM for the device is disabled at the early stage
causing i2c transfer to fail. Make changes to serve transfer with force
resume.
1. Register interrupt with IRQF_EARLY_RESUME and IRQF_NO_SUSPEND flags
to avoid timeout of transfer when IRQ is not enabled during early stage.
2. Do force resume if pm_runtime_get_sync() is failing after system
suspend when runtime PM is not enabled.
3. Increment power usage count after forced resume to balance
it against regular runtime suspend.
Co-developed-by: Viken Dadhaniya <[email protected]>
Signed-off-by: Viken Dadhaniya <[email protected]>
Signed-off-by: Mukesh Kumar Savaliya <[email protected]>
---
drivers/i2c/busses/i2c-qcom-geni.c | 55 ++++++++++++++++++++++++------
1 file changed, 45 insertions(+), 10 deletions(-)
diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
index da94df466e83..ed8201983a03 100644
--- a/drivers/i2c/busses/i2c-qcom-geni.c
+++ b/drivers/i2c/busses/i2c-qcom-geni.c
@@ -134,6 +134,8 @@ struct geni_i2c_clk_fld {
u8 t_cycle_cnt;
};
+static int geni_i2c_runtime_resume(struct device *dev);
+
/*
* Hardware uses the underlying formula to calculate time periods of
* SCL clock cycle. Firmware uses some additional cycles excluded from the
@@ -677,22 +679,48 @@ static int geni_i2c_fifo_xfer(struct geni_i2c_dev *gi2c,
return num;
}
+static int geni_i2c_force_resume(struct geni_i2c_dev *gi2c)
+{
+ struct device *dev = gi2c->se.dev;
+ int ret;
+
+ ret = geni_i2c_runtime_resume(dev);
+ if (ret) {
+ dev_err(gi2c->se.dev, "Error turning SE resources:%d\n", ret);
+ pm_runtime_put_noidle(dev);
+ pm_runtime_set_suspended(dev);
+ return ret;
+ }
+ pm_runtime_get_noresume(dev);
+ pm_runtime_set_active(dev);
+ return ret;
+}
+
static int geni_i2c_xfer(struct i2c_adapter *adap,
struct i2c_msg msgs[],
int num)
{
struct geni_i2c_dev *gi2c = i2c_get_adapdata(adap);
+ struct device *dev = gi2c->se.dev;
int ret;
gi2c->err = 0;
reinit_completion(&gi2c->done);
- ret = pm_runtime_get_sync(gi2c->se.dev);
- if (ret < 0) {
- dev_err(gi2c->se.dev, "error turning SE resources:%d\n", ret);
- pm_runtime_put_noidle(gi2c->se.dev);
- /* Set device in suspended since resume failed */
- pm_runtime_set_suspended(gi2c->se.dev);
- return ret;
+
+ if (!pm_runtime_enabled(dev) && gi2c->suspended) {
+ dev_dbg(gi2c->se.dev, "RT_PM disabled, Do force resume, usage_count:%d\n",
+ atomic_read(&dev->power.usage_count));
+ ret = geni_i2c_force_resume(gi2c);
+ if (ret)
+ return ret;
+ } else {
+ ret = pm_runtime_get_sync(dev);
+ if (ret == -EACCES && gi2c->suspended) {
+ dev_dbg(gi2c->se.dev, "PM get_sync() failed-%d, force resume\n", ret);
+ ret = geni_i2c_force_resume(gi2c);
+ if (ret)
+ return ret;
+ }
}
qcom_geni_i2c_conf(gi2c);
@@ -702,8 +730,15 @@ static int geni_i2c_xfer(struct i2c_adapter *adap,
else
ret = geni_i2c_fifo_xfer(gi2c, msgs, num);
- pm_runtime_mark_last_busy(gi2c->se.dev);
- pm_runtime_put_autosuspend(gi2c->se.dev);
+ if (!pm_runtime_enabled(dev) && !gi2c->suspended) {
+ pm_runtime_put_noidle(dev);
+ pm_runtime_set_suspended(dev);
+ gi2c->suspended = 0;
+ } else {
+ pm_runtime_mark_last_busy(gi2c->se.dev);
+ pm_runtime_put_autosuspend(gi2c->se.dev);
+ }
+
gi2c->cur = NULL;
gi2c->err = 0;
return ret;
@@ -820,7 +855,7 @@ static int geni_i2c_probe(struct platform_device *pdev)
init_completion(&gi2c->done);
spin_lock_init(&gi2c->lock);
platform_set_drvdata(pdev, gi2c);
- ret = devm_request_irq(dev, gi2c->irq, geni_i2c_irq, 0,
+ ret = devm_request_irq(dev, gi2c->irq, geni_i2c_irq, IRQF_EARLY_RESUME | IRQF_NO_SUSPEND,
dev_name(dev), gi2c);
if (ret) {
dev_err(dev, "Request_irq failed:%d: err:%d\n",
--
2.25.1
Hi Mukesh,
On Thu, Mar 28, 2024 at 06:07:43PM +0530, Mukesh Kumar Savaliya wrote:
> pm_runtime_get_sync() function fails during PM early resume and returning
> -EACCES because runtime PM for the device is disabled at the early stage
> causing i2c transfer to fail. Make changes to serve transfer with force
> resume.
>
> 1. Register interrupt with IRQF_EARLY_RESUME and IRQF_NO_SUSPEND flags
> to avoid timeout of transfer when IRQ is not enabled during early stage.
> 2. Do force resume if pm_runtime_get_sync() is failing after system
> suspend when runtime PM is not enabled.
> 3. Increment power usage count after forced resume to balance
> it against regular runtime suspend.
>
> Co-developed-by: Viken Dadhaniya <[email protected]>
> Signed-off-by: Viken Dadhaniya <[email protected]>
> Signed-off-by: Mukesh Kumar Savaliya <[email protected]>
Is this a fix? O mostly an improvement?
..
> gi2c->err = 0;
> reinit_completion(&gi2c->done);
> - ret = pm_runtime_get_sync(gi2c->se.dev);
> - if (ret < 0) {
> - dev_err(gi2c->se.dev, "error turning SE resources:%d\n", ret);
> - pm_runtime_put_noidle(gi2c->se.dev);
> - /* Set device in suspended since resume failed */
> - pm_runtime_set_suspended(gi2c->se.dev);
> - return ret;
> +
> + if (!pm_runtime_enabled(dev) && gi2c->suspended) {
> + dev_dbg(gi2c->se.dev, "RT_PM disabled, Do force resume, usage_count:%d\n",
dev
nit: you could leave a space after the ':'.
> + atomic_read(&dev->power.usage_count));
> + ret = geni_i2c_force_resume(gi2c);
> + if (ret)
> + return ret;
> + } else {
> + ret = pm_runtime_get_sync(dev);
> + if (ret == -EACCES && gi2c->suspended) {
> + dev_dbg(gi2c->se.dev, "PM get_sync() failed-%d, force resume\n", ret);
dev
> + ret = geni_i2c_force_resume(gi2c);
> + if (ret)
> + return ret;
> + }
Are we missing some cases here? Do we need a few more else's?
Andi
> }
>
> qcom_geni_i2c_conf(gi2c);
> @@ -702,8 +730,15 @@ static int geni_i2c_xfer(struct i2c_adapter *adap,
> else
> ret = geni_i2c_fifo_xfer(gi2c, msgs, num);
>
> - pm_runtime_mark_last_busy(gi2c->se.dev);
> - pm_runtime_put_autosuspend(gi2c->se.dev);
> + if (!pm_runtime_enabled(dev) && !gi2c->suspended) {
> + pm_runtime_put_noidle(dev);
> + pm_runtime_set_suspended(dev);
this looks like repeated code, how about making it a function?
> + gi2c->suspended = 0;
> + } else {
> + pm_runtime_mark_last_busy(gi2c->se.dev);
> + pm_runtime_put_autosuspend(gi2c->se.dev);
> + }
> +
> gi2c->cur = NULL;
> gi2c->err = 0;
> return ret;
> @@ -820,7 +855,7 @@ static int geni_i2c_probe(struct platform_device *pdev)
> init_completion(&gi2c->done);
> spin_lock_init(&gi2c->lock);
> platform_set_drvdata(pdev, gi2c);
> - ret = devm_request_irq(dev, gi2c->irq, geni_i2c_irq, 0,
> + ret = devm_request_irq(dev, gi2c->irq, geni_i2c_irq, IRQF_EARLY_RESUME | IRQF_NO_SUSPEND,
Can you provide a bit more information on how an early interrupt
would be handled once the device is resumed?
Thanks,
Andi
> dev_name(dev), gi2c);
> if (ret) {
> dev_err(dev, "Request_irq failed:%d: err:%d\n",
> --
> 2.25.1
>
Thanks Andi !
On 3/30/2024 3:24 AM, Andi Shyti wrote:
> Hi Mukesh,
>
> On Thu, Mar 28, 2024 at 06:07:43PM +0530, Mukesh Kumar Savaliya wrote:
>> pm_runtime_get_sync() function fails during PM early resume and returning
>> -EACCES because runtime PM for the device is disabled at the early stage
>> causing i2c transfer to fail. Make changes to serve transfer with force
>> resume.
>>
>> 1. Register interrupt with IRQF_EARLY_RESUME and IRQF_NO_SUSPEND flags
>> to avoid timeout of transfer when IRQ is not enabled during early stage.
>> 2. Do force resume if pm_runtime_get_sync() is failing after system
>> suspend when runtime PM is not enabled.
>> 3. Increment power usage count after forced resume to balance
>> it against regular runtime suspend.
>>
>> Co-developed-by: Viken Dadhaniya <[email protected]>
>> Signed-off-by: Viken Dadhaniya <[email protected]>
>> Signed-off-by: Mukesh Kumar Savaliya <[email protected]>
>
> Is this a fix? O mostly an improvement?
It's an improvement to serve transfer during early resume time. Doesn't
fix any crash issue.
>
> ...
>
>> gi2c->err = 0;
>> reinit_completion(&gi2c->done);
>> - ret = pm_runtime_get_sync(gi2c->se.dev);
>> - if (ret < 0) {
>> - dev_err(gi2c->se.dev, "error turning SE resources:%d\n", ret);
>> - pm_runtime_put_noidle(gi2c->se.dev);
>> - /* Set device in suspended since resume failed */
>> - pm_runtime_set_suspended(gi2c->se.dev);
>> - return ret;
>> +
>> + if (!pm_runtime_enabled(dev) && gi2c->suspended) {
>> + dev_dbg(gi2c->se.dev, "RT_PM disabled, Do force resume, usage_count:%d\n",
>
> dev
>
Sure, Done.
> nit: you could leave a space after the ':'.
>
Sure, Done.
>> + atomic_read(&dev->power.usage_count));
>> + ret = geni_i2c_force_resume(gi2c);
>> + if (ret)
>> + return ret;
>> + } else {
>> + ret = pm_runtime_get_sync(dev);
>> + if (ret == -EACCES && gi2c->suspended) {
>> + dev_dbg(gi2c->se.dev, "PM get_sync() failed-%d, force resume\n", ret);
>
> dev
>
Done.
>> + ret = geni_i2c_force_resume(gi2c);
>> + if (ret)
>> + return ret;
>> + }
>
> Are we missing some cases here? Do we need a few more else's?
>
> Andi
>
No More else cases required.
>> }
>>
>> qcom_geni_i2c_conf(gi2c);
>> @@ -702,8 +730,15 @@ static int geni_i2c_xfer(struct i2c_adapter *adap,
>> else
>> ret = geni_i2c_fifo_xfer(gi2c, msgs, num);
>>
>> - pm_runtime_mark_last_busy(gi2c->se.dev);
>> - pm_runtime_put_autosuspend(gi2c->se.dev);
>> + if (!pm_runtime_enabled(dev) && !gi2c->suspended) {
>> + pm_runtime_put_noidle(dev);
>> + pm_runtime_set_suspended(dev);
>
> this looks like repeated code, how about making it a function?
>
Checked it, but seems we need additional flag too to be added at one
place where as common part is 2 lines of code. If this code continues to
be repeated, i can think of keeping under a wrapper function. Please let
me know if still needed to make a separate function.
>> + gi2c->suspended = 0;
>> + } else {
>> + pm_runtime_mark_last_busy(gi2c->se.dev);
>> + pm_runtime_put_autosuspend(gi2c->se.dev);
>> + }
>> +
>> gi2c->cur = NULL;
>> gi2c->err = 0;
>> return ret;
>> @@ -820,7 +855,7 @@ static int geni_i2c_probe(struct platform_device *pdev)
>> init_completion(&gi2c->done);
>> spin_lock_init(&gi2c->lock);
>> platform_set_drvdata(pdev, gi2c);
>> - ret = devm_request_irq(dev, gi2c->irq, geni_i2c_irq, 0,
>> + ret = devm_request_irq(dev, gi2c->irq, geni_i2c_irq, IRQF_EARLY_RESUME | IRQF_NO_SUSPEND,
>
> Can you provide a bit more information on how an early interrupt
> would be handled once the device is resumed?
>
Sure, Let me go little descriptive here.
Post system suspend when system resume starts (because of PCI/touch
device wakeup interrupt or anything else).
1.That time i2c client device handler will directly start i2c transfer,
but we could not serve transfer because device is runtime suspended and
runtime PM remains disabled. This happens during early_resume callback
time, hence we have added forced_resume()
Basically system is still suspended and not reached to the point of
enabling runtime PM of the i2c master.
2. If the IRQF_EARLY_RESUME is not registered, then we get timeout as
the interrupt is not enabled. kernel/irq/pm.c has function which Enables
interrupt lines having IRQF_EARLY_RESUME set during syscore instead of
device resume time.
irq_pm_syscore_resume() => resume_irqs() => __enable_irq()
> Thanks,
> Andi
>
>> dev_name(dev), gi2c);
>> if (ret) {
>> dev_err(dev, "Request_irq failed:%d: err:%d\n",
>> --
>> 2.25.1
>>
On Thu, Mar 28, 2024 at 06:07:43PM +0530, Mukesh Kumar Savaliya wrote:
> pm_runtime_get_sync() function fails during PM early resume and returning
> -EACCES because runtime PM for the device is disabled at the early stage
> causing i2c transfer to fail. Make changes to serve transfer with force
> resume.
>
> 1. Register interrupt with IRQF_EARLY_RESUME and IRQF_NO_SUSPEND flags
> to avoid timeout of transfer when IRQ is not enabled during early stage.
> 2. Do force resume if pm_runtime_get_sync() is failing after system
> suspend when runtime PM is not enabled.
> 3. Increment power usage count after forced resume to balance
> it against regular runtime suspend.
>
> Co-developed-by: Viken Dadhaniya <[email protected]>
> Signed-off-by: Viken Dadhaniya <[email protected]>
> Signed-off-by: Mukesh Kumar Savaliya <[email protected]>
> ---
> drivers/i2c/busses/i2c-qcom-geni.c | 55 ++++++++++++++++++++++++------
> 1 file changed, 45 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
> index da94df466e83..ed8201983a03 100644
> --- a/drivers/i2c/busses/i2c-qcom-geni.c
> +++ b/drivers/i2c/busses/i2c-qcom-geni.c
> @@ -134,6 +134,8 @@ struct geni_i2c_clk_fld {
> u8 t_cycle_cnt;
> };
>
> +static int geni_i2c_runtime_resume(struct device *dev);
> +
> /*
> * Hardware uses the underlying formula to calculate time periods of
> * SCL clock cycle. Firmware uses some additional cycles excluded from the
> @@ -677,22 +679,48 @@ static int geni_i2c_fifo_xfer(struct geni_i2c_dev *gi2c,
> return num;
> }
>
> +static int geni_i2c_force_resume(struct geni_i2c_dev *gi2c)
> +{
> + struct device *dev = gi2c->se.dev;
> + int ret;
> +
> + ret = geni_i2c_runtime_resume(dev);
> + if (ret) {
> + dev_err(gi2c->se.dev, "Error turning SE resources:%d\n", ret);
"error turning"? How about "Failed to enable SE resources: %d\n"?
> + pm_runtime_put_noidle(dev);
> + pm_runtime_set_suspended(dev);
These two where the error-handling for pm_runtime_get_sync() failing, in
one case below you get here after pm_runtime_get_sync() failed in the
other you have not attempted to call that function.
Do you really get through this with things balanced?
> + return ret;
> + }
> + pm_runtime_get_noresume(dev);
> + pm_runtime_set_active(dev);
> + return ret;
ret is 0.
> +}
> +
> static int geni_i2c_xfer(struct i2c_adapter *adap,
> struct i2c_msg msgs[],
> int num)
> {
> struct geni_i2c_dev *gi2c = i2c_get_adapdata(adap);
> + struct device *dev = gi2c->se.dev;
> int ret;
>
> gi2c->err = 0;
> reinit_completion(&gi2c->done);
> - ret = pm_runtime_get_sync(gi2c->se.dev);
> - if (ret < 0) {
> - dev_err(gi2c->se.dev, "error turning SE resources:%d\n", ret);
> - pm_runtime_put_noidle(gi2c->se.dev);
> - /* Set device in suspended since resume failed */
> - pm_runtime_set_suspended(gi2c->se.dev);
> - return ret;
> +
> + if (!pm_runtime_enabled(dev) && gi2c->suspended) {
> + dev_dbg(gi2c->se.dev, "RT_PM disabled, Do force resume, usage_count:%d\n",
"RT_PM" is not a widely used abbreviation for this...
> + atomic_read(&dev->power.usage_count));
> + ret = geni_i2c_force_resume(gi2c);
> + if (ret)
> + return ret;
> + } else {
> + ret = pm_runtime_get_sync(dev);
> + if (ret == -EACCES && gi2c->suspended) {
> + dev_dbg(gi2c->se.dev, "PM get_sync() failed-%d, force resume\n", ret);
Different abbreviation, different formatting of error value in log
line...
> + ret = geni_i2c_force_resume(gi2c);
> + if (ret)
> + return ret;
This chunk looks identical to the chunk above, can this somehow be
restructured to avoid the duplication?
> + }
> }
>
> qcom_geni_i2c_conf(gi2c);
> @@ -702,8 +730,15 @@ static int geni_i2c_xfer(struct i2c_adapter *adap,
> else
> ret = geni_i2c_fifo_xfer(gi2c, msgs, num);
>
> - pm_runtime_mark_last_busy(gi2c->se.dev);
> - pm_runtime_put_autosuspend(gi2c->se.dev);
I'm not sure I follow this part, please add a comment here for the
future reader.
> + if (!pm_runtime_enabled(dev) && !gi2c->suspended) {
> + pm_runtime_put_noidle(dev);
> + pm_runtime_set_suspended(dev);
> + gi2c->suspended = 0;
Why alter suspended flag in xfer()?
Regards,
Bjorn
> + } else {
> + pm_runtime_mark_last_busy(gi2c->se.dev);
> + pm_runtime_put_autosuspend(gi2c->se.dev);
> + }
> +
> gi2c->cur = NULL;
> gi2c->err = 0;
> return ret;
> @@ -820,7 +855,7 @@ static int geni_i2c_probe(struct platform_device *pdev)
> init_completion(&gi2c->done);
> spin_lock_init(&gi2c->lock);
> platform_set_drvdata(pdev, gi2c);
> - ret = devm_request_irq(dev, gi2c->irq, geni_i2c_irq, 0,
> + ret = devm_request_irq(dev, gi2c->irq, geni_i2c_irq, IRQF_EARLY_RESUME | IRQF_NO_SUSPEND,
> dev_name(dev), gi2c);
> if (ret) {
> dev_err(dev, "Request_irq failed:%d: err:%d\n",
> --
> 2.25.1
>