From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C3C96C193F2 for ; Wed, 22 May 2019 09:30:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9A26A20815 for ; Wed, 22 May 2019 09:30:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728802AbfEVJar (ORCPT ); Wed, 22 May 2019 05:30:47 -0400 Received: from mailgw02.mediatek.com ([1.203.163.81]:15374 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1728536AbfEVJar (ORCPT ); Wed, 22 May 2019 05:30:47 -0400 X-UUID: 6572bcb62c544fa1ac84fa752fc1c9c8-20190522 X-UUID: 6572bcb62c544fa1ac84fa752fc1c9c8-20190522 Received: from mtkcas35.mediatek.inc [(172.27.4.253)] by mailgw02.mediatek.com (envelope-from ) (mailgw01.mediatek.com ESMTP with TLS) with ESMTP id 272006990; Wed, 22 May 2019 17:30:39 +0800 Received: from MTKCAS36.mediatek.inc (172.27.4.186) by MTKMBS31N1.mediatek.inc (172.27.4.69) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Wed, 22 May 2019 17:30:37 +0800 Received: from [10.17.3.153] (172.27.4.253) by MTKCAS36.mediatek.inc (172.27.4.170) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Wed, 22 May 2019 17:30:36 +0800 Message-ID: <1558517436.10179.388.camel@mhfsdcap03> Subject: RE: [PATCH v5 4/6] usb: roles: add API to get usb_role_switch by node From: Chunfeng Yun To: Biju Das CC: Heikki Krogerus , Rob Herring , Greg Kroah-Hartman , "Mark Rutland" , Matthias Brugger , Adam Thomson , Li Jun , Badhri Jagan Sridharan , Hans de Goede , Andy Shevchenko , Min Guo , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-usb@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-mediatek@lists.infradead.org" , Linus Walleij Date: Wed, 22 May 2019 17:30:36 +0800 In-Reply-To: References: <1557823643-8616-1-git-send-email-chunfeng.yun@mediatek.com> <1557823643-8616-5-git-send-email-chunfeng.yun@mediatek.com> <20190517103736.GA1490@kuha.fi.intel.com> <20190517130511.GA1887@kuha.fi.intel.com> <1558319951.10179.352.camel@mhfsdcap03> <20190520080359.GC1887@kuha.fi.intel.com> <20190520083601.GE1887@kuha.fi.intel.com> <20190521095839.GI1887@kuha.fi.intel.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit MIME-Version: 1.0 X-MTK: N Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Hi Biju, On Wed, 2019-05-22 at 08:05 +0000, Biju Das wrote: > Hi Heikki, > > Thanks for the feedback. > > > Subject: Re: [PATCH v5 4/6] usb: roles: add API to get usb_role_switch by > > node > > > > On Mon, May 20, 2019 at 09:45:46AM +0000, Biju Das wrote: > > > > > > > > > Hi Heikki, > > > > > > Thanks for the feedback. > > > > > > > Subject: Re: [PATCH v5 4/6] usb: roles: add API to get > > > > usb_role_switch by node > > > > > > > > On Mon, May 20, 2019 at 08:06:41AM +0000, Biju Das wrote: > > > > > Hi Heikki, > > > > > > > > > > > Subject: Re: [PATCH v5 4/6] usb: roles: add API to get > > > > > > usb_role_switch by node > > > > > > > > > > > > On Mon, May 20, 2019 at 10:39:11AM +0800, Chunfeng Yun wrote: > > > > > > > Hi, > > > > > > > On Fri, 2019-05-17 at 16:05 +0300, Heikki Krogerus wrote: > > > > > > > > Hi, > > > > > > > > > > > > > > > > On Fri, May 17, 2019 at 01:37:36PM +0300, Heikki Krogerus wrote: > > > > > > > > > On Tue, May 14, 2019 at 04:47:21PM +0800, Chunfeng Yun > > wrote: > > > > > > > > > > Add fwnode_usb_role_switch_get() to make easier to get > > > > > > > > > > usb_role_switch by fwnode which register it. > > > > > > > > > > It's useful when there is not device_connection > > > > > > > > > > registered between two drivers and only knows the fwnode > > > > > > > > > > which register usb_role_switch. > > > > > > > > > > > > > > > > > > > > Signed-off-by: Chunfeng Yun > > > > > > > > > > Tested-by: Biju Das > > > > > > > > > > > > > > > > > > Acked-by: Heikki Krogerus > > > > > > > > > > > > > > > > > > > > > > > > > Hold on. I just noticed Rob's comment on patch 2/6, where he > > > > > > > > points out that you don't need to use device graph since the > > > > > > > > controller is the parent of the connector. Doesn't that mean > > > > > > > > you don't really need this API? > > > > > > > No, I still need it. > > > > > > > The change is about the way how to get fwnode; when use device > > > > > > > graph, get fwnode by of_graph_get_remote_node(); but now will > > > > > > > get fwnode by of_get_parent(); > > > > > > > > > > > > OK, I get that, but I'm still not convinced about if something > > > > > > like this function is needed at all. I also have concerns > > > > > > regarding how you are using the function. I'll explain in > > > > > > comment to the patch 5/6 in this > > > > series... > > > > > > > > > > FYI, Currently I am also using this api in my patch series. > > > > > https://patchwork.kernel.org/patch/10944637/ > > > > > > > > Yes, and I have the same question for you I jusb asked in comment I > > > > added to the patch 5/6 of this series. Why isn't usb_role_switch_get() > > enough? > > > > > > Currently no issue. It will work with this api as well, since the port node is > > part of controller node. > > > For eg:- > > > https://patchwork.kernel.org/patch/10944627/ > > > > > > However if any one adds port node inside the connector node, then this > > api may won't work as expected. > > > Currently I get below error > > > > > > [ 2.299703] OF: graph: no port node found in > > /soc/i2c@e6500000/hd3ss3220@47 > > > > We need to understand why is that happening? > > > > Form the stack trace the parent node is "parent_node=hd3ss3220@47" , instead of the "connector" node. > That is the reason for the above error. > > [ 2.442429] of_graph_get_next_endpoint.part.0+0x28/0x168 > [ 2.447889] of_fwnode_graph_get_next_endpoint+0x5c/0xb0 > [ 2.453267] fwnode_graph_get_next_endpoint+0x20/0x30 > [ 2.458374] device_connection_find_match+0x74/0x1a0 > [ 2.463399] usb_role_switch_get+0x20/0x28 > [ 2.467542] hd3ss3220_probe+0xc4/0x218 > > The use case is > > &i2c0 { > hd3ss3220@47 { > compatible = "ti,hd3ss3220"; > > usb_con: connector { > compatible = "usb-c-connector"; > port { > hd3ss3220_ep: endpoint { > remote-endpoint = <&usb3_role_switch>; > }; > }; > }; > }; > }; > > &usb3_peri0 { > companion = <&xhci0>; > usb-role-switch; > > port { > usb3_role_switch: endpoint { > remote-endpoint = <&hd3ss3220_ep>; > }; > }; > }; > > Q1) How do we modify the usb_role_switch_get() function to search > Child(connector) and child's endpoint? How about firstly finding connector node in fwnode_graph_devcon_match(), then search each endpoint? > > > It looks like we have an issue somewhere in the code, and instead of fixing > > that, you are working around it. Let's not do that. > > OK. > > Regards, > Biju >