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 <quic_vdadhani@xxxxxxxxxxx>
> Signed-off-by: Viken Dadhaniya <quic_vdadhani@xxxxxxxxxxx>
> Signed-off-by: Mukesh Kumar Savaliya <quic_msavaliy@xxxxxxxxxxx>
> ---
> 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
>
