From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH RESEND] ARM: tegra: set regulator full constraints Date: Fri, 01 Nov 2013 10:01:27 -0600 Message-ID: <5273D057.10505@wwwdotorg.org> References: <1383203126-3243-1-git-send-email-wni@nvidia.com> <52727DB7.9030109@wwwdotorg.org> <52730480.6020607@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <52730480.6020607-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Wei Ni , "broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org" Cc: "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-tegra@vger.kernel.org On 10/31/2013 07:31 PM, Wei Ni wrote: > On 10/31/2013 11:56 PM, Stephen Warren wrote: >> On 10/31/2013 01:05 AM, Wei Ni wrote: >>> Set full constraints during machine initialisation, so that the >>> regulator_get() can get the dummy regulator if the regulator is >>> physically present and enabled. >>> Discussed this in the link: >>> https://lkml.org/lkml/2013/10/8/40 >> >> Is this needed to fix some bug that'll be in 3.13 or earlier, or does it >> just solve a problem that will only be exposed in new code that will >> appear in 3.14 or later? > > Let me explain this patch. > I discovered this problem when I worked on lm90 driver. > When I appiled my lm90 power control patches (this patch still in > review), I found the lm90 will be probed failed on Ventana board, > because on this board, the lm90 regulator is physically present and > enabled, so the lm90 driver can't use regulator_get() to get regulator, > and if we didn't set this full contraints, it can't get the dummy > regulator either, then probe failed. > So I think it's better to applied this patch earliy, because this solve > the compatible issue between Mark's dumy regulator patches, device > driver and DT. To be honest, I don't really understand the answer and I don't think it's answering my question. Anyway, Mark requested changes to the patch, so I'll wait for V2 anyway.