From mboxrd@z Thu Jan  1 00:00:00 1970
From: Arnd Bergmann <arnd@arndb.de>
Subject: Re: [PATCH] ARM: dts: fix MMC2 regulators for Exynos5420 Arndale Octa board
Date: Wed, 08 Oct 2014 17:20:42 +0200
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To: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>, Kukjin Kim <kgene.kim@samsung.com>, Doug Anderson <dianders@google.com>, Yuvaraj Kumar C D <yuvaraj.cd@samsung.com>, "cpgs ." <cpgs@samsung.com>, Yuvaraj Kumar C D <yuvaraj.cd@gmail.com>, linux-samsung-soc <linux-samsung-soc@vger.kernel.org>, "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org>, Jaehoon Chung <jh80.chung@samsung.com>, Chris Ball <cjb@laptop.org>, Seung-Won Jeon <tgih.jun@samsung.com>, linux-mmc <linux-mmc@vger.kernel.org>, Sonny Rao <sonnyrao@chromium.org>, Tomasz Figa <tomasz.figa@gmail.com>, SUNIL JOSHI <joshi@samsung.com>, PRASHANTH GODREHAL <prashanth.g@samsung.com>, ALIM AKHTAR <alim.akhtar@samsung.com>, Javier Martinez Canillas <javier.martinez@collabora.co.uk>, Abhilash Kesavan <a.kesavan@samsung.com>

On Wednesday 08 October 2014 14:50:46 Ulf Hansson wrote:
> On 8 October 2014 14:07, Arnd Bergmann <arnd@arndb.de> wrote:
> > On Thursday 02 October 2014 20:16:44 Ulf Hansson wrote:
> >> On 2 October 2014 18:10, Bartlomiej Zolnierkiewicz
> >> <b.zolnierkie@samsung.com> wrote:
> >> > Regulators for MMC2 (SD card) are PVDD_TFLASH_2V8 (LDO19) for vmmc
> >> > and PVDD_APIO_MMCOFF_2V8 (LDO13) for vqmmc.  Currently the device
> >> > tree entry for MMC2 uses PVDD_PRE_1V8 (LDO10) for vmmc and vqmmc is
> >> > not specified.  Fix it.
> >> >
> >> > Without this patch:
> >> > - "mmc: dw_mmc: use mmc_regulator_get_supply to handle regulators"
> >> >   patch causes a SD card detection to fail
> >> > - "mmc: dw_mmc: Support voltage changes" patch causes a boot hang
> >> >
> >> > This patch fixes both above problems.
> >> >
> >> > Suggested-by: Doug Anderson <dianders@google.com>
> >> > Cc: Yuvaraj Kumar C D <yuvaraj.cd@samsung.com>
> >> > Cc: Ulf Hansson <ulf.hansson@linaro.org>
> >> > Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
> >> > Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
> >>
> >> Unless it causes a bunch non-trivial conflicts, I suggest we take this
> >> through my mmc tree to not break bisectability.
> >
> > Have you tried if it conflicts with arm-soc? If not,
> >
> > Acked-by: Arnd Bergmann <arnd@arndb.de>
> 
> In conflicts, but it's trivial to fix it.
> 
> Since it actually fixes a regression which is inserted from my mmc
> tree, I thought it makes sense to take it through here. Anyway, the
> decision is yours.
> 

Why does it cause a regression though? Does this mean you are breaking
any boot with an old DT file and a new kernel? That would be very
bad, the driver is supposed to keep working with an existing dtb.

	Arnd