Date: Wed, 06 Jun 2007 09:45:49 +0300 From: Krassimir Slavchev <krassi@bulinfo.net> To: ticso@cicely.de Cc: ticso@cicely12.cicely.de, arm@freebsd.org Subject: Re: timeout while detecting SD card Message-ID: <4666581D.9050009@bulinfo.net> In-Reply-To: <20070605165908.GP16463@cicely12.cicely.de> References: <53067.2001:6f8:101e:0:20e:cff:fe6d:6adb.1181056352.squirrel@webmail.alpha-tierchen.de> <20070605154250.GN16463@cicely12.cicely.de> <20070605.100615.-1384053623.imp@bsdimp.com> <20070605165908.GP16463@cicely12.cicely.de>
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Bernd Walter wrote: > On Tue, Jun 05, 2007 at 10:06:15AM -0600, M. Warner Losh wrote: > >> In message: <20070605154250.GN16463@cicely12.cicely.de> >> Bernd Walter <ticso@cicely12.cicely.de> writes: >> : On Tue, Jun 05, 2007 at 05:12:32PM +0200, Björn König wrote: >> : > Hello, >> : > >> : > yet another problem. I can't access the SD card. I googled a bit and >> : > noticed that I'm not the only one with this problem, but I haven't found a >> : > solution yet. Here are some details: >> : > >> : > Everything seems to work fine until sending the app command in >> : > mmc_wait_for_app_cmd. The driver gets an interrupt with a "response >> : > time-out error" set in status register. That's it. >> >> I think this is what I fixed by increasing the timeout... >> >> : > I tried to find the problem and executed an Atmel MCI demo programm in >> : > kernel shortly after mmc_scan. It does basically the same and detects the >> : > card in the SD card bay properly. There is one obvious difference: the >> : > demo doesn't use an interrupt service routine. >> : > >> : > I hope someone has a hint for me, once again. ;-) >> : >> : All drivers expect the bootcode to setup the io-lines. >> : I also saw the effect that when booting via bootspi (MCI init added) >> : then the first boot may not find the card. >> : Booting via boot2 always succeed. >> : You may want to check about what redboot does about MCI init. >> >> The theory I read somewhere in linux land was that the boot loader was >> responsible for setting up the various I/O lines. I coded full speed >> ahead with this assumption. If it isn't actually true, then we can >> reevaluate. It isn't that hard to add a board init function. But >> then we need to add a board id to boot2 and have the kernel use it. I >> believe that redboot already passes one in... >> > > I personally like the current situation is best. > I can have the same image for variuous boards, whichout having to > define a new board name everytime. > Just a few points in respect to hardcoded clock rates may be a problem. > E.g. MCK can be higher than 60MHz if you accept to reduce the CPU clock, > which may or may not be faster depending on the io usage. > Not to speak about overclocking, which, if I got the RM9200 datasheet > right, allows higher clock rates by just overclocking the PLL. > I use MCK 80MHz and cpu clock 240MHz without any problems.
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