From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Mon, 17 Jun 2019 11:39:21 +0100 From: Lorenzo Pieralisi Subject: Re: [PATCH V4 27/28] PCI: tegra: Add support for GPIO based PERST# Message-ID: <20190617103921.GA20619@e121166-lin.cambridge.arm.com> References: <20190614143222.GB23116@e121166-lin.cambridge.arm.com> <1508173d-0ecc-f498-6ab2-78a718086b35@nvidia.com> <20190614145023.GA24588@e121166-lin.cambridge.arm.com> <20190614152304.GK15526@ulmo> <20190614155934.GA28253@e121166-lin.cambridge.arm.com> <51e4ae62-f842-1d2f-fbca-0b2063dd53a6@nvidia.com> <20190614165353.GB30511@e121166-lin.cambridge.arm.com> <1c662f82-8329-5e1b-58bf-b2fe1643adb0@nvidia.com> <20190617094839.GE18020@e121166-lin.cambridge.arm.com> <0f9bb97d-5a30-a654-0cc6-a57a7bd894c8@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0f9bb97d-5a30-a654-0cc6-a57a7bd894c8@nvidia.com> To: Manikanta Maddireddy Cc: Thierry Reding , bhelgaas@google.com, robh+dt@kernel.org, mark.rutland@arm.com, jonathanh@nvidia.com, vidyas@nvidia.com, linux-tegra@vger.kernel.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org List-ID: On Mon, Jun 17, 2019 at 03:57:09PM +0530, Manikanta Maddireddy wrote: > > > On 17-Jun-19 3:18 PM, Lorenzo Pieralisi wrote: > > On Fri, Jun 14, 2019 at 10:53:13PM +0530, Manikanta Maddireddy wrote: > > > > [...] > > > >>> Ok. My point then is that you have no way to enforce this requirement on > >>> platforms that actually need it, I do not even know if there is a > >>> way you can do it (I was thinking along the lines of using a > >>> compatible string to detect whether the GPIO #PERST reset is mandatory) > >>> but maybe this is not even a SOC property. > >>> > >>> Maybe what I am asking is overkill, I just wanted to understand. > >>> > >>> I was just asking a question to understand how you handle the case > >>> where a GPIO pin definition is missing in DT for a platform that > >>> actually needs it, the driver will probe but nothing will work. > >>> > >>> It would be good to describe this and capture it in the commit log. > >>> > >>> Thanks, > >>> Lorenzo > >> I can't think of a easy way to enforce this requirement. As you said > >> compatible string is per SOC, so we can't use it for a platform. > >> This issue is present on only one platform, so it is hard to miss the > >> DT property. That is the reason for publishing this patch with out this > >> enforcement in driver. > >> > >> I thought for changing PERST# to GPIO for all platform, but testing is > >> a tedious job. Also I don't have Tegra20 and Tegra30 platforms. > > I can't help with that. > > > >> Do you want me to drop the patch or update the limitation in the commit > >> log? > > It is Thierry's call, if he is OK with it fine by me, please do > > update the commit log, it will help everybody understand. > > > > Lorenzo > > Sure, I will update the commit log in V5. > Please let me know if you completed reviewing this series, I will > send V5 addressing review comments in this patch. Post v5, we should be able to get it in v5.3, thanks. Lorenzo