On Sat, Mar 25, 2023 at 10:22:17PM +0530, Manivannan Sadhasivam wrote: > dwc3-qcom driver is capable of doing runtime PM on its own, but currently > it requires userspace intervention to enable it. But there is no harm in > letting the driver to enable runtime PM on its own. So let's get rid of the > "pm_runtime_forbid()" and make sure that the dependency is maintained with > child devices using "pm_suspend_ignore_children(dev, false)". Well, the potential harm is that these paths have hardly been tested so enabling it by default is a risk (e.g. as you noticed when trying to enable this by default). And especially if we don't address the layering violations first. > Also during remove(), the device needs to be waken up first if it was > runtime suspended. Finally, pm_runtime_allow() can be removed. > > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx> > --- > drivers/usb/dwc3/dwc3-qcom.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c > index f1059dfcb0e8..5f26bb66274f 100644 > --- a/drivers/usb/dwc3/dwc3-qcom.c > +++ b/drivers/usb/dwc3/dwc3-qcom.c > @@ -920,7 +920,7 @@ static int dwc3_qcom_probe(struct platform_device *pdev) > qcom->is_suspended = false; > pm_runtime_set_active(dev); > pm_runtime_enable(dev); > - pm_runtime_forbid(dev); > + pm_suspend_ignore_children(dev, false); There's no need to explicitly disable ignore-children as that is the default. > return 0; > > @@ -948,6 +948,8 @@ static int dwc3_qcom_remove(struct platform_device *pdev) > struct device *dev = &pdev->dev; > int i; > > + pm_runtime_get_sync(dev); This call needs to be balanced. But this is a fix for a bug in the current implementation that should go in a separate patch. > + > device_remove_software_node(&qcom->dwc3->dev); > of_platform_depopulate(dev); > > @@ -960,7 +962,6 @@ static int dwc3_qcom_remove(struct platform_device *pdev) > dwc3_qcom_interconnect_exit(qcom); > reset_control_assert(qcom->resets); > > - pm_runtime_allow(dev); > pm_runtime_disable(dev); > > return 0; Johan