From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: [PATCH v2 3/5] Documentation: dt-bindings: Add snps,need-phy-for-wake for dwc2 USB Date: Mon, 29 Apr 2019 20:23:28 -0500 Message-ID: <20190430012328.GA25660@bogus> References: <20190418001356.124334-1-dianders@chromium.org> <20190418001356.124334-4-dianders@chromium.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20190418001356.124334-4-dianders@chromium.org> Sender: linux-kernel-owner@vger.kernel.org To: Douglas Anderson Cc: Minas Harutyunyan , Felipe Balbi , heiko@sntech.de, Alan Stern , Artur Petrosyan , amstan@chromium.org, linux-rockchip@lists.infradead.org, William Wu , linux-usb@vger.kernel.org, Stefan Wahren , Randy Li , zyw@rock-chips.com, mka@chromium.org, ryandcase@chromium.org, Amelie Delaunay , jwerner@chromium.org, dinguyen@opensource.altera.com, Elaine Zhang , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Greg Kroah-Hartman , Mark Rutland List-Id: linux-rockchip.vger.kernel.org On Wed, Apr 17, 2019 at 05:13:54PM -0700, Douglas Anderson wrote: > Some SoCs with a dwc2 USB controller may need to keep the PHY on to > support remote wakeup. Allow specifying this as a device tree > property. > > Signed-off-by: Douglas Anderson > --- > For relevant prior discussion on this patch, see: > > https://lkml.kernel.org/r/1435017144-2971-3-git-send-email-dianders@chromium.org > > I didn't make any changes from the prior version since I never found > out what Rob thought of my previous arguments. If folks want a > change, perhaps they could choose from these options: > > 1. Assume that all dwc2 hosts would like to keep their PHY on for > suspend if there's a USB wakeup enabled, thus we totally drop this > binding. This doesn't seem super great to me since I'd bet that > many devices that use dwc2 weren't designed for USB wakeup (they > may not keep enough clocks or rails on) so we might be wasting > power for nothing. 1b. Use SoC specific compatible strings to enable/disable remote wake-up. We can debate what the default is I guess. > 2. Rename this property to "snps,wakeup-from-suspend-with-phy" to make > it more obvious that this property is intended both to document > that wakeup from suspend is possible and that we need the PHY for > said wakeup. > 3. Rename this property to "snps,can-wakeup-from-suspend" and assume > it's implicit that if we can wakeup from suspend that we need to > keep the PHY on. If/when someone shows that a device exists using > dwc2 where we can wakeup from suspend without the PHY they can add > a new property. > > Changes in v2: None > > Documentation/devicetree/bindings/usb/dwc2.txt | 3 +++ > 1 file changed, 3 insertions(+) > From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Subject: [v2,3/5] Documentation: dt-bindings: Add snps,need-phy-for-wake for dwc2 USB From: Rob Herring Message-Id: <20190430012328.GA25660@bogus> Date: Mon, 29 Apr 2019 20:23:28 -0500 To: Douglas Anderson Cc: Minas Harutyunyan , Felipe Balbi , heiko@sntech.de, Alan Stern , Artur Petrosyan , amstan@chromium.org, linux-rockchip@lists.infradead.org, William Wu , linux-usb@vger.kernel.org, Stefan Wahren , Randy Li , zyw@rock-chips.com, mka@chromium.org, ryandcase@chromium.org, Amelie Delaunay , jwerner@chromium.org, dinguyen@opensource.altera.com, Elaine Zhang , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Greg Kroah-Hartman , Mark Rutland List-ID: T24gV2VkLCBBcHIgMTcsIDIwMTkgYXQgMDU6MTM6NTRQTSAtMDcwMCwgRG91Z2xhcyBBbmRlcnNv biB3cm90ZToKPiBTb21lIFNvQ3Mgd2l0aCBhIGR3YzIgVVNCIGNvbnRyb2xsZXIgbWF5IG5lZWQg dG8ga2VlcCB0aGUgUEhZIG9uIHRvCj4gc3VwcG9ydCByZW1vdGUgd2FrZXVwLiAgQWxsb3cgc3Bl Y2lmeWluZyB0aGlzIGFzIGEgZGV2aWNlIHRyZWUKPiBwcm9wZXJ0eS4KPiAKPiBTaWduZWQtb2Zm LWJ5OiBEb3VnbGFzIEFuZGVyc29uIDxkaWFuZGVyc0BjaHJvbWl1bS5vcmc+Cj4gLS0tCj4gRm9y IHJlbGV2YW50IHByaW9yIGRpc2N1c3Npb24gb24gdGhpcyBwYXRjaCwgc2VlOgo+IAo+IGh0dHBz Oi8vbGttbC5rZXJuZWwub3JnL3IvMTQzNTAxNzE0NC0yOTcxLTMtZ2l0LXNlbmQtZW1haWwtZGlh bmRlcnNAY2hyb21pdW0ub3JnCj4gCj4gSSBkaWRuJ3QgbWFrZSBhbnkgY2hhbmdlcyBmcm9tIHRo ZSBwcmlvciB2ZXJzaW9uIHNpbmNlIEkgbmV2ZXIgZm91bmQKPiBvdXQgd2hhdCBSb2IgdGhvdWdo dCBvZiBteSBwcmV2aW91cyBhcmd1bWVudHMuICBJZiBmb2xrcyB3YW50IGEKPiBjaGFuZ2UsIHBl cmhhcHMgdGhleSBjb3VsZCBjaG9vc2UgZnJvbSB0aGVzZSBvcHRpb25zOgo+IAo+IDEuIEFzc3Vt ZSB0aGF0IGFsbCBkd2MyIGhvc3RzIHdvdWxkIGxpa2UgdG8ga2VlcCB0aGVpciBQSFkgb24gZm9y Cj4gICAgc3VzcGVuZCBpZiB0aGVyZSdzIGEgVVNCIHdha2V1cCBlbmFibGVkLCB0aHVzIHdlIHRv dGFsbHkgZHJvcCB0aGlzCj4gICAgYmluZGluZy4gIFRoaXMgZG9lc24ndCBzZWVtIHN1cGVyIGdy ZWF0IHRvIG1lIHNpbmNlIEknZCBiZXQgdGhhdAo+ICAgIG1hbnkgZGV2aWNlcyB0aGF0IHVzZSBk d2MyIHdlcmVuJ3QgZGVzaWduZWQgZm9yIFVTQiB3YWtldXAgKHRoZXkKPiAgICBtYXkgbm90IGtl ZXAgZW5vdWdoIGNsb2NrcyBvciByYWlscyBvbikgc28gd2UgbWlnaHQgYmUgd2FzdGluZwo+ICAg IHBvd2VyIGZvciBub3RoaW5nLgoKMWIuIFVzZSBTb0Mgc3BlY2lmaWMgY29tcGF0aWJsZSBzdHJp bmdzIHRvIGVuYWJsZS9kaXNhYmxlIHJlbW90ZSAKd2FrZS11cC4gV2UgY2FuIGRlYmF0ZSB3aGF0 IHRoZSBkZWZhdWx0IGlzIEkgZ3Vlc3MuCgo+IDIuIFJlbmFtZSB0aGlzIHByb3BlcnR5IHRvICJz bnBzLHdha2V1cC1mcm9tLXN1c3BlbmQtd2l0aC1waHkiIHRvIG1ha2UKPiAgICBpdCBtb3JlIG9i dmlvdXMgdGhhdCB0aGlzIHByb3BlcnR5IGlzIGludGVuZGVkIGJvdGggdG8gZG9jdW1lbnQKPiAg ICB0aGF0IHdha2V1cCBmcm9tIHN1c3BlbmQgaXMgcG9zc2libGUgYW5kIHRoYXQgd2UgbmVlZCB0 aGUgUEhZIGZvcgo+ICAgIHNhaWQgd2FrZXVwLgo+IDMuIFJlbmFtZSB0aGlzIHByb3BlcnR5IHRv ICJzbnBzLGNhbi13YWtldXAtZnJvbS1zdXNwZW5kIiBhbmQgYXNzdW1lCj4gICAgaXQncyBpbXBs aWNpdCB0aGF0IGlmIHdlIGNhbiB3YWtldXAgZnJvbSBzdXNwZW5kIHRoYXQgd2UgbmVlZCB0bwo+ ICAgIGtlZXAgdGhlIFBIWSBvbi4gIElmL3doZW4gc29tZW9uZSBzaG93cyB0aGF0IGEgZGV2aWNl IGV4aXN0cyB1c2luZwo+ICAgIGR3YzIgd2hlcmUgd2UgY2FuIHdha2V1cCBmcm9tIHN1c3BlbmQg d2l0aG91dCB0aGUgUEhZIHRoZXkgY2FuIGFkZAo+ICAgIGEgbmV3IHByb3BlcnR5Lgo+IAo+IENo YW5nZXMgaW4gdjI6IE5vbmUKPiAKPiAgRG9jdW1lbnRhdGlvbi9kZXZpY2V0cmVlL2JpbmRpbmdz L3VzYi9kd2MyLnR4dCB8IDMgKysrCj4gIDEgZmlsZSBjaGFuZ2VkLCAzIGluc2VydGlvbnMoKykK Pgo=