Re: [PATCH] mmc: omap_hsmmc: Add support for Erratum 2.1.1.128 in device tree boot

From: Felipe Balbi <balbi@ti.com>
To: Nishanth Menon <nm@ti.com>
Cc: dt list <devicetree@vger.kernel.org>,
	Balaji T K <balajitk@ti.com>, Tony Lindgren <tony@atomide.com>,
	linux-mmc@vger.kernel.org, Chris Ball <chris@printf.net>,
	balbi@ti.com, linux-omap <linux-omap@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH] mmc: omap_hsmmc: Add support for Erratum 2.1.1.128 in device tree boot
Date: Tue, 21 Jan 2014 13:45:17 -0600	[thread overview]
Message-ID: <20140121194517.GU30451@saruman.home> (raw)
In-Reply-To: <CAGo_u6qHFmgb9s9Taw2NAuBgjLY5tDW5XHbfik7PHcTArW7szg@mail.gmail.com>


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On Tue, Jan 21, 2014 at 01:39:20PM -0600, Nishanth Menon wrote:
> On Tue, Jan 21, 2014 at 12:05 PM, Felipe Balbi <balbi@ti.com> wrote:
> > Hi,
> >
> > On Tue, Jan 21, 2014 at 11:38:00AM -0600, Nishanth Menon wrote:
> >> On 01/20/2014 05:39 PM, Felipe Balbi wrote:
> >> > On Mon, Jan 20, 2014 at 05:29:02PM -0600, Nishanth Menon wrote:
> >> >> When device is booted using devicetree, platforms impacted by
> >> >> Erratum 2.1.1.128 is not detected easily in the mmc driver. This erratum
> >> >> indicates that the module cannot do multi-block transfers.
> >> >>
> >> >> Handle this by providing a boolean flag to indicate to driver that it is
> >> >> working on a hardware with mentioned limitation.
> >> >
> >> > sure there's no way of reading the revision register to figure this one
> >> > out without having to add a new DT attribute ?
> >> >
> >> I did a quick patch to read the Module revision register:
> >> http://slexy.org/view/s21TKvlWlR
> >>
> >> sdp2430: Revision: 1.2, Spec: 0.0, normal interrupt
> >>
> >> OMAP3430-ldp: (ES2.1): Revision: 2.6, Spec: 0.0, normal interrupt
> >> SDP3430:(ES3.0) Revision: 2.6, Spec: 0.0, normal interrupt
> >> AM3517-evm: (ES1.1): Revision: 2.6, Spec: 0.0, normal interrupt
> >> AM3517-crane:(ES1.1): Revision: 2.6, Spec: 0.0, normal interrupt
> >>
> >> AM37x-evm: (ES1.2) Revision: 2.6, Spec: 0.0, normal interrupt
> >> OMAP3630-beag-xm (ES1.2): Revision: 2.6, Spec: 0.0, normal interrupt
> >>
> >> am335x-evm:(ES1.0): Revision: 3.1, Spec: 0.1, normal interrupt
> >> am335x-sk: (ES2.1): Revision: 3.1, Spec: 0.1, normal interrupt
> >> am335x-beaglebone-black:(ES2.0): Revision: 3.1, Spec: 0.1, normal
> >> interrupt
> >>
> >> sdp4430.txt: (ES2.2): Revision: 3.1, Spec: 0.1, normal interrupt
> >>
> >> OMAP4460-panda-es (ES1.1): Revision: 3.1, Spec: 0.1, normal interrupt
> >>
> >> OMAP5uevm:(ES2.0): Revision: 3.3, Spec: 0.2, normal interrupt
> >> dra7-evm (es1.1): Revision: 3.3, Spec: 0.2, normal interrupt
> >>
> >>
> >> OMAP3430-ldp seems to be the only one impacted with module revision
> >> 2.6 -> so using revision information is not really helpful here. Hence
> >> the usage of a flag in dt attribute to indicate hardware impacted by
> >> erratum.
> >
> > alright, that's too bad. Seems like revision in this module isn't very
> > useful :-(
> 
> Can I take that as an acked-by?

sure

Acked-by: Felipe Balbi <balbi@ti.com>

-- 
balbi

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