From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [PATCH 2/2] arm: dts: dra76-evm: Disable rtc target module References: <20190516090657.25211-1-j-keerthy@ti.com> <20190516090657.25211-2-j-keerthy@ti.com> <20190516161256.GB5447@atomide.com> <20190516164729.GC5447@atomide.com> From: keerthy Message-ID: Date: Thu, 16 May 2019 22:24:14 +0530 MIME-Version: 1.0 In-Reply-To: <20190516164729.GC5447@atomide.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit To: Tony Lindgren Cc: robh+dt@kernel.org, devicetree@vger.kernel.org, linux-omap@vger.kernel.org, t-kristo@ti.com List-ID: On 5/16/2019 10:17 PM, Tony Lindgren wrote: > * keerthy [190516 16:31]: >> >> >> On 5/16/2019 9:42 PM, Tony Lindgren wrote: >>> Hi, >>> >>> * Keerthy [190516 09:06]: >>>> rtc is fused out on dra76 and accessing target module >>>> register is causing a boot crash hence disable it. >>> >>> So for a fix, can we have a separate dra7 something dtsi file >>> to disable these instead? >>> >>> Or are there already multiple SoC revisions for the same EVM? >> >> dra76 & dra71 have rtc fused out. So i did not introduce a new dtsi file >> to disable. > > But then any new board with dra76 or dra71 will need to debug > the same issue again. Sure we can get away for now tweaking the > board file, but to me it sounds like it's going to be more > devices that will be affected too? Okay. This is a SoC related issue so yes any new board will have to again implement disabling. > > Is there some feature matrix available somewhere online? Not that i know of. I will try finding something. > >>> Then in the long run, if there are the same EVMs with multiple >>> SoC options, the best thing to do is to would be to detect the >>> SoC type and update the property dynamically to set the features >>> not available on the booted SoC to status = "disabled". Seems >>> like that could be done in the ti-sysc driver probe unless needed >>> earlier. >> >> For now rtc is disabled only in dra71/dra76. So best disable it in the >> evm.dts? Not sure if we need dynamic disabling as we know at DT level that >> it is to be disabled. > > Well the thing is we should make introducing new board dts files > as easy as including the SoC dtsi file and with that it should > boot with no extra debugging. > > How about add minimal dra76 and dra71 dtsi files in addition to > the board specific fix(es)? Then for v5.3, we can deal adding more > dra7 specifc evm files using these dtsi files or dynamically start > disabling modules. You mean having a dra76/dra71.dtsi with rtc/usb4_tm disabled and that gets included in dra76/dra71-evm.dts? > > Regards, > > Tony >