Re: [PATCH v6 01/12] usb: hcd: Initialize hcd->flags to 0

From	Peter Chen <hzpeterchen@gmail.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v6 01/12] usb: hcd: Initialize hcd->flags to 0
Date	2016-04-07 11:50 +0200
Message-ID	<rleJA-1Ne-7@gated-at.bofh.it> (permalink)
References	<rkzQ5-4UX-1@gated-at.bofh.it> <rkzQ8-4UX-55@gated-at.bofh.it> <rkOYO-880-9@gated-at.bofh.it> <rkPia-8gZ-9@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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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@ti.com> 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
sure the clocks and regulators are off, and hcd will be zero-initialized
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.

-- 

Best Regards,
Peter Chen

Thread

[PATCH v6 00/12] USB OTG/dual-role framework Roger Quadros <rogerq@ti.com> - 2016-04-05 16:10 +0200
  [PATCH v6 10/12] usb: doc: dt-binding: Add otg-controller property Roger Quadros <rogerq@ti.com> - 2016-04-05 16:10 +0200
  [PATCH v6 09/12] usb: gadget: udc: adapt to OTG core Roger Quadros <rogerq@ti.com> - 2016-04-05 16:10 +0200
  [PATCH v6 12/12] usb: host: xhci-plat: Add otg device to platform data Roger Quadros <rogerq@ti.com> - 2016-04-05 16:10 +0200
    RE: [PATCH v6 12/12] usb: host: xhci-plat: Add otg device to platform  data Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> - 2016-04-06 05:30 +0200
      Re: [PATCH v6 12/12] usb: host: xhci-plat: Add otg device to platform  data Roger Quadros <rogerq@ti.com> - 2016-04-06 08:40 +0200
  [PATCH v6 06/12] usb: otg: get rid of CONFIG_USB_OTG_FSM in favour of CONFIG_USB_OTG Roger Quadros <rogerq@ti.com> - 2016-04-05 16:10 +0200
  [PATCH v6 07/12] usb: otg: add OTG/dual-role core Roger Quadros <rogerq@ti.com> - 2016-04-05 16:10 +0200
    RE: [PATCH v6 07/12] usb: otg: add OTG/dual-role core Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> - 2016-04-07 11:00 +0200
      Re: [PATCH v6 07/12] usb: otg: add OTG/dual-role core Roger Quadros <rogerq@ti.com> - 2016-04-07 13:50 +0200
        RE: [PATCH v6 07/12] usb: otg: add OTG/dual-role core Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> - 2016-04-08 13:30 +0200
          Re: [PATCH v6 07/12] usb: otg: add OTG/dual-role core Roger Quadros <rogerq@ti.com> - 2016-04-11 13:00 +0200
            RE: [PATCH v6 07/12] usb: otg: add OTG/dual-role core Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> - 2016-04-14 10:40 +0200
              Re: [PATCH v6 07/12] usb: otg: add OTG/dual-role core Roger Quadros <rogerq@ti.com> - 2016-04-14 13:10 +0200
                RE: [PATCH v6 07/12] usb: otg: add OTG/dual-role core Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> - 2016-04-14 13:20 +0200
                Re: [PATCH v6 07/12] usb: otg: add OTG/dual-role core Roger Quadros <rogerq@ti.com> - 2016-04-14 13:40 +0200
                RE: [PATCH v6 07/12] usb: otg: add OTG/dual-role core Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> - 2016-04-15 12:00 +0200
                Re: [PATCH v6 07/12] usb: otg: add OTG/dual-role core Roger Quadros <rogerq@ti.com> - 2016-04-15 13:00 +0200
                RE: [PATCH v6 07/12] usb: otg: add OTG/dual-role core Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> - 2016-04-15 12:10 +0200
    Re: [PATCH v6 07/12] usb: otg: add OTG/dual-role core Peter Chen <hzpeterchen@gmail.com> - 2016-04-15 11:40 +0200
      Re: [PATCH v6 07/12] usb: otg: add OTG/dual-role core Roger Quadros <rogerq@ti.com> - 2016-04-15 13:10 +0200
  [PATCH v6 05/12] usb: gadget.h: Add OTG to gadget interface Roger Quadros <rogerq@ti.com> - 2016-04-05 16:10 +0200
  [PATCH v6 02/12] usb: hcd.h: Add OTG to HCD interface Roger Quadros <rogerq@ti.com> - 2016-04-05 16:10 +0200
  [PATCH v6 04/12] usb: otg-fsm: move host controller operations into usb_otg->hcd_ops Roger Quadros <rogerq@ti.com> - 2016-04-05 16:10 +0200
  [PATCH v6 11/12] usb: core: hub: Notify OTG fsm when A device sets b_hnp_enable Roger Quadros <rogerq@ti.com> - 2016-04-05 16:10 +0200
  [PATCH v6 01/12] usb: hcd: Initialize hcd->flags to 0 Roger Quadros <rogerq@ti.com> - 2016-04-05 16:10 +0200
    Re: [PATCH v6 01/12] usb: hcd: Initialize hcd->flags to 0 Felipe Balbi <balbi@kernel.org> - 2016-04-06 08:20 +0200
      Re: [PATCH v6 01/12] usb: hcd: Initialize hcd->flags to 0 Roger Quadros <rogerq@ti.com> - 2016-04-06 08:40 +0200
        Re: [PATCH v6 01/12] usb: hcd: Initialize hcd->flags to 0 Peter Chen <hzpeterchen@gmail.com> - 2016-04-07 11:50 +0200
          Re: [PATCH v6 01/12] usb: hcd: Initialize hcd->flags to 0 Roger Quadros <rogerq@ti.com> - 2016-04-07 12:50 +0200
            Re: [PATCH v6 01/12] usb: hcd: Initialize hcd->flags to 0 Peter Chen <hzpeterchen@gmail.com> - 2016-04-08 03:10 +0200
              Re: [PATCH v6 01/12] usb: hcd: Initialize hcd->flags to 0 Roger Quadros <rogerq@ti.com> - 2016-04-08 09:20 +0200
                Re: [PATCH v6 01/12] usb: hcd: Initialize hcd->flags to 0 Peter Chen <hzpeterchen@gmail.com> - 2016-04-08 10:00 +0200
  [PATCH v6 08/12] usb: hcd: Adapt to OTG core Roger Quadros <rogerq@ti.com> - 2016-04-05 16:20 +0200

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