From mboxrd@z Thu Jan 1 00:00:00 1970 From: Frank Rowand Subject: Re: How delete node or property in overlayd dts? Date: Sat, 18 Aug 2018 23:12:49 -0700 Message-ID: References: <78f06f2d-7561-dde9-c155-9f1612f9067a@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <78f06f2d-7561-dde9-c155-9f1612f9067a@gmail.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Zhang Bo Cc: Rob Herring , devicetree@vger.kernel.org, "linux-kernel@vger.kernel.org" List-Id: devicetree@vger.kernel.org On 08/18/18 03:38, Zhang Bo wrote: > > 在 2018/8/18 1:47, Rob Herring 写道: >> On Tue, Aug 14, 2018 at 7:26 PM Frank Rowand wrote: >>> On 08/14/18 07:46, 张波 wrote: >>>> /delete-node/ /delete-prop/ could be used in dtsi files without device >>>> tree overlay. >>>> >>>> but with device tree overlay,  /delete-node/ and  /delete-prop/ are not work. >>>> How to delete property and node in overlay dts? >>>> >>>> for example, >>>> in basel.dts have following node >>>> node1 { >>>>      property1; >>>>      property3; >>>>      node2 { >>>>          property2; >>>>      } >>>> } >>>> >>>> in overlay.dts as following >>>>   node1 { >>>>      /delete-property/ property1; >>>>      /delete-node/ node2; >>>> } >>>> >>>> after overlay, property1 and node2 is not deleted. >>>> >>> The /delete-node/ and /delete-prop/ directives are only used by the >>> dtc compiler within a single compilation. >>> >>> There is nothing in the format of a devicetree blob to represent the >>> notion of deleting a property or a node. >>> >>> You can not delete a property or a node in an overlay dtb. >> Though you can add/override 'status' with 'status = "disabled";' which >> should be treated very similar to a node not being present. I say >> similar because it's a source of bugs for the OS to fail to pay >> attention to status property. > > there is document in https://android.googlesource.com/kernel/msm/+/android-7.0.0_r0.11/Documentation/devicetree/overlay-notes.txt> > In above document, remove node or property by adding - operator before node or property. but I didn't find it in released kernel source code, Is there any update plan about this problem? > > { > >     property-a;       /* add property-a to the target */ > >     -proptery-b;     /* remove property-b from the target */ > >     -node-b {          /* remove an exiting node-b */ > >         ... > >     } > > } > > As far as I can tell, this version of overlay-notes.txt has never been in the mainline kernel source. There is no plan to support such a syntax. -Frank