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Date: Wed, 05 Nov 2014 21:50:52 -0700
From: Stephen Warren <swarren@wwwdotorg.org>
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To: Scott Branden <sbranden@broadcom.com>,
        Ulf Hansson <ulf.hansson@linaro.org>,
        Russell King <rmk+kernel@arm.linux.org.uk>,
        Peter Griffin <peter.griffin@linaro.org>,
        Chris Ball <chris@printf.net>, Piotr Krol <pietrushnic@gmail.com>
CC: linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org,
        Joe Perches <joe@perches.com>, linux-rpi-kernel@lists.infradead.org,
        Ray Jui <rjui@broadcom.com>, bcm-kernel-feedback-list@broadcom.com
Subject: Re: [PATCHv2 5/5] mmc: sdhci-bcm2835: add sdhci quirk SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12
References: <Scott Branden <sbranden@broadcom.com> <1414651017-3545-1-git-send-email-sbranden@broadcom.com> <1414651017-3545-6-git-send-email-sbranden@broadcom.com> <5459AEEA.8050503@wwwdotorg.org> <5459CB76.3060601@broadcom.com>
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On 11/05/2014 12:02 AM, Scott Branden wrote:
> On 14-11-04 09:00 PM, Stephen Warren wrote:
>> On 10/30/2014 12:36 AM, Scott Branden wrote:
>>> SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12 is missing and needed for this
>>> controller.
>>
>> This seems fine, although any explanation of why this quirk is needed
>> would be useful.
>>
> I don't know who to talk to at Arasan about this.  Will try hunting
> around a little for more info as to why this is needed to have eMMC and
> SD work properly through our internal testing on other non-2835 chipset
> that shares the same SDHCI controller as 2835.

I thought I heard that this wasn't a bug in the controller itself, but
rather an integration issue between the IP core and the register bus
it's attached to. Consequently, it may be SoC-specific or at least have
SoC-specific variations?