From mboxrd@z Thu Jan 1 00:00:00 1970 From: Giuseppe CAVALLARO Subject: Re: stmmac DT property snps,axi_all Date: Mon, 12 Dec 2016 14:16:52 +0100 Message-ID: References: <51f8249e-bdb9-e3a7-5d82-7ac869316f0e@axis.com> <120aca00-02a8-3d88-7aad-a21d239aafb2@st.com> <6c79e89f-52a2-3ac9-c976-6aa006e5ac38@st.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Cc: To: Alexandre Torgue , Niklas Cassel Return-path: Received: from mx08-00178001.pphosted.com ([91.207.212.93]:49319 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750712AbcLLNQ6 (ORCPT ); Mon, 12 Dec 2016 08:16:58 -0500 In-Reply-To: <6c79e89f-52a2-3ac9-c976-6aa006e5ac38@st.com> Sender: netdev-owner@vger.kernel.org List-ID: Hello On 12/9/2016 5:06 PM, Alexandre Torgue wrote: > Hi Niklas > > On 12/09/2016 10:53 AM, Niklas Cassel wrote: >> On 12/09/2016 10:20 AM, Niklas Cassel wrote: >>> On 12/08/2016 02:36 PM, Alexandre Torgue wrote: >>>> Hi Niklas, >>>> >>>> On 12/05/2016 05:18 PM, Niklas Cassel wrote: >>>>> Hello Giuseppe >>>>> >>>>> >>>>> I'm trying to figure out what snps,axi_all is supposed to represent. >>>>> >>>>> It appears that the value is saved, but never used in the code. >>>>> >>>>> Looking at the register specification, I'm guessing that it represents >>>>> Address-Aligned Beats, but there is already the property snps,aal >>>>> for that. >>>> IMO, it is not useful. Indeed AXI_AAL is a read only bit (in AXI bus >>>> mode register) and reflects the aal bit in DMA bus register. >>>> As you know we use "snps,aal" to set aal bit in DMA bus register. >>>> So "snps,axi_all" entry seems useless. Let's see with Peppe. >>> Ok, I see. GMAC and GMAC4 is different here. >>> >>> For GMAC4 AAL only exists in DMA_SYS_BUS_MODE. >>> It's not reflected anywhere else. >>> >>> The code is correct in the driver. >>> >>> If snps,axi_all is just created for a read-only register, >>> and it is currently never used in the code, >>> while we have snps,aal, which is correct and works, >>> I guess it should be ok to remove snps,axi_all. >>> >>> I can cook up a patch. >>> >> >> Here we go :) >> >> I will send it as a real patch once net-next reopens. > > Thanks ;). Just check with Peppe next week (as he added in the past this > property). Yes, we can conclude that the axi_all can be safely removed from DT, in fact on all GMACs the AaL will be set via DMA_BUS_MODE register. peppe