Skip site navigation (1)Skip section navigation (2)
Date:      Sun, 18 Jan 2015 17:03:12 +0900
From:      "Daisuke Aoyama" <aoyama@peach.ne.jp>
To:        <freebsd-arm@freebsd.org>
Subject:   HS mode in RPi
Message-ID:  <AF35369EC7D84B59A5BBAADD77DC1687@ad.peach.ne.jp>

next in thread | raw e-mail | index | archive | help
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,
-- 
Daisuke Aoyama
 



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?AF35369EC7D84B59A5BBAADD77DC1687>