From mboxrd@z Thu Jan 1 00:00:00 1970 From: Olliver Schinagl Subject: Re: [PATCH 1/1] ARM: dts: sunxi: Add a olinuxino-lime2-emmc Date: Fri, 15 Jul 2016 11:01:15 +0200 Message-ID: References: <1461827998-12192-1-git-send-email-oliver@schinagl.nl> <5729F07C.3080308@schinagl.nl> <948be370-4401-43cb-862e-d4376755a75d@googlegroups.com> <5729F6D6.8030100@schinagl.nl> <4704fa35-9a2a-4e6e-8fd4-f4778405c598@googlegroups.com> <572A0052.9060202@schinagl.nl> <2e745ef7-ddc0-40fc-b867-414543690276@googlegroups.com> <572A10B3.2020803@schinagl.nl> <4375220a-f939-4ed0-a6d7-2cf887b07509@googlegroups.com> <9fe7ebb6-6d74-4b73-b6d6-93b79650cdb6@googlegroups.com> <9745a80b-5444-43f7-b772-68684c96c9e5@googlegroups.com> <57322C8D.5060806@schinagl.nl> <8afbe753-4e74-4b30-ad7e-a12027d28264@googlegroups.com> <57323CAB.7090202@schinagl.nl> <6bfa242e-c0ce-4dc5-9144-b3f16d8fb75c@googlegroups.com> <5732EB34.6070203@schinagl.nl> <78b34fdb-bb6e-4043-8f5b-93bc551513c7@googlegroups.com> <6214e145-b408-70f1-bc6f-db066cbe94b1@schinagl.nl> Reply-To: o.schinagl-U3FVU11NWA554TAoqtyWWQ@public.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="------------D6F746D86C942FF47A9467AA" Return-path: Sender: linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org In-Reply-To: <6214e145-b408-70f1-bc6f-db066cbe94b1-dxLnbx3+1qmEVqv0pETR8A@public.gmane.org> List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , To: stefan.mavrodiev-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, linux-sunxi Cc: christo.radev-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, radoslav.kolev-1W28NRE8jL9DPfheJLI6IQ@public.gmane.org, wens-jdAy2FN1RRM@public.gmane.org, maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org, tsvetan-kyXcfZUBQGPQT0dZR+AlfA@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, pawel.moll-5wv7dgnIgG8@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org, galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org, hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, dev-3kdeTeqwOZ9EV1b7eY7vFQ@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org This is a multi-part message in MIME format. --------------D6F746D86C942FF47A9467AA Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable Stefan, On 15-07-16 10:57, Olliver Schinagl wrote: > On 15-07-16 10:39, stefan.mavrodiev-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org wrote: >> Hi Olliver, >> >> Why are you using nRST signal? >> What I mean is this pin is inactive on this eMMC chip. To use the signal >> byte 162 of ECSD registers should be written. > Then that sounds like a bug in the mmc layer I would say (or a missing=20 > attribute in the dts), we have a nRST signal it is wired, if the chip=20 > ignores it, then nothing lost, if the chip needs to be initialized=20 > with byte 162 of the ECSD register to make the nRST work, then that it=20 > sounds like it should be fixed there? > > By ommitting the nRST signal just because the chip isn't properly=20 > initialized sounds more like a work-around to me, but I could be wrong=20 > and see things wrong. I just did a quick google query, and found the following post [0]. And=20 it appears it's a fuse in the eMMC chip to enable/disable this=20 functionality. I guess, but not sure, that our mmc driver in=20 u-boot/kernel does not use the reset flag properly (always high) if that=20 fuse has been enabled. I can imagine when using older u-boots this flag=20 isn't enabled, the fuse is not triggered yet and the pin is thus ignored? > > What do the mmc guys, who have far more experience here, say? > >> >> On my board, this "reset" signal causes eMMC not to work. > That supprises me, as afaik I was using it just fine... > > Olliver >> >> Best regards, >> Stefan Mavrodiev > [0]=20 https://groups.google.com/forum/#!category-topic/beagleboard/u-boot/1XwSNdZ= ii1Y --=20 Met vriendelijke groeten, Kind regards, =E4=B8=8E=E4=BA=B2=E5=88=87=E7=9A= =84=E9=97=AE=E5=80=99 Olliver Schinagl Software Engineer Research & Development Ultimaker B.V. --=20 You received this message because you are subscribed to the Google Groups "= linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an e= mail to linux-sunxi+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org For more options, visit https://groups.google.com/d/optout. --------------D6F746D86C942FF47A9467AA Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable

Stefan,


On 15-07-16 10:57, Olliver Schinagl wrote:
On 15-07-16 10:39, stefan.mavrodiev-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org= wrote:
Hi Olliver,

Why are you using nRST signal?
What I mean is this pin is inactive on this eMMC chip. To use the signal
byte 162 of ECSD registers should be written.
Then that sounds like a bug in the mmc layer I would say (or a missing attribute in the dts), we have a nRST signal it is wired, if the chip ignores it, then nothing lost, if the chip needs to be initialized with byte 162 of the ECSD register to make the nRST work, then that it sounds like it should be fixed there?

By ommitting the nRST signal just because the chip isn't properly initialized sounds more like a work-around to me, but I could be wrong and see things wrong.
I just did a quick google query, and found the following post [0]. And it appears it's a fuse in the eMMC chip to enable/disable this functionality. I guess, but not sure, that our mmc driver in u-boot/kernel does not use the reset flag properly (always high) if that fuse has been enabled. I can imagine when using older u-boots this flag isn't enabled, the fuse is not triggered yet and the pin is thus ignored?


What do the mmc guys, who have far more experience here, say?


On my board, this "reset" signal causes eMMC not to work.
That supprises me, as afaik I was using it just fine...

Olliver

Best regards,
Stefan Mavrodiev


[0] https://groups.google.com/= forum/#!category-topic/beagleboard/u-boot/1XwSNdZii1Y
--=20
Met vriendelijke groeten, Kind regards, =E4=B8=8E=E4=BA=B2=E5=88=87=E7=9A=
=84=E9=97=AE=E5=80=99

Olliver Schinagl
Software Engineer
Research & Development
Ultimaker B.V.

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