Date: Sun, 18 Jan 2015 13:41:53 -0700 From: Ian Lepore <ian@freebsd.org> To: Daisuke Aoyama <aoyama@peach.ne.jp> Cc: freebsd-arm@freebsd.org Subject: Re: HS mode in RPi Message-ID: <1421613713.14601.333.camel@freebsd.org> In-Reply-To: <AF35369EC7D84B59A5BBAADD77DC1687@ad.peach.ne.jp> References: <AF35369EC7D84B59A5BBAADD77DC1687@ad.peach.ne.jp>
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On Sun, 2015-01-18 at 17:03 +0900, Daisuke Aoyama wrote: > Hi, > > r277307 add bcm2835_sdhci_hs=1, but this is wrong. > It does not cover HS problem. The quirk and HS switching is not same. > It's only one of problems on some SD card. > I'm using bcm2835_sdhci_hispd_bit but this may not useful. > > HS mode on emmc=100MHz and core=250MHz cause SD card corruption. > To avoid clock domain crossing, you need emmc=250MHz and bcm2835_sdhci_hs=1. > But emmc=250MHz means running as 41MHz on HS mode(250MHz / 2N divider). > However, it seems Linux use emmc=250MHz by default. > > I suggest use emmc=250MHz or keep bcm2835_sdhci_hs=0 by default at this time. > > Regards, The change back to hs=1 default was made on the assumption that people are using the newer firmware files that set the emmc clock to 250. Anyone using older firmware can add this to their config.txt on the boot partition: init_emmc_clock=250000000 -- Ian
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