On 07/04/16 12:42, Peter Chen wrote: > On Wed, Apr 06, 2016 at 09:32:22AM +0300, Roger Quadros wrote: >> On 06/04/16 09:09, Felipe Balbi wrote: >>> >>> Hi, >>> >>> Roger Quadros <rogerq@xxxxxx> writes: >>>> diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c >>>> index 2ca2cef..6b1930d 100644 >>>> --- a/drivers/usb/core/hcd.c >>>> +++ b/drivers/usb/core/hcd.c >>>> @@ -2706,6 +2706,7 @@ int usb_add_hcd(struct usb_hcd *hcd, >>>> int retval; >>>> struct usb_device *rhdev; >>>> >>>> + hcd->flags = 0; >>> > > I am not sure if this usb_add(remove)_hcd pair is safe and clean enough > for start/stop host role. From my point, we may need to do like > .probe/.remove host platform driver interface. In that case, we can make probe and remove are meant to be called from bus layer. I do not see a way how OTG framework can call probe/remove of HCD driver. Some HCDs may be platform devices, some PCI, so different entities are calling the HCD .probe hook. > sure the clocks and regulators are off, and hcd will be zero-initialized why can't we make that sure that is taken care of within the hcd_ops? Why should some driver keep its regulators and clocks enabled when hcd is stopped? It doesn't need to. If it is doing so now, it needs to be fixed. > next time. Assume we are at gadget mode, we may not hope the vbus regulator > is still on which is for host only. So, this part may need to implement > by each user. > Yes, correctness of this has to be taken care by each driver. cheers, -roger -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
