Re: pb with sheeva plug and usb/sd memory cards
Le 23/08/2012 21:00, mick a écrit :
> On Wed, 22 Aug 2012 16:10:14 -0700
> Rick Thomas <rbthomas@pobox.com> allegedly wrote:
>
>>
>> There have been persistent reports of flaky results with SD cards on
>> Sheeva (and other) Plug devices. The best theory I've heard so far
>> is that the SD interface hardware/software in the Plugs is vey picky
>> about the specs and timing of the SD card interface. Many people
>> have no problems for years, but if you happen to pick a card from a
>> slightly out-of-spec batch, you will have no end of intermittent
>> problems.
>>
>> Why not just go back to using a USB flash stick?
>>
>> Rick
>>
>
> I had persistent problems with SD cards when I first bought a
> sheevaplug back in 2010. (See http://baldric.net/2010/03/30/unplugged/
> for example). My problems only disappeared when I moved to using a
> (powered) USB disk as boot and filesystem.
>
> Mick
The master problem about SDHC/MMC is that the driver is a quick
adaptation of the Marvell U-Boot for denx u-boot.
It's not ported, nor maintained and not very tested by Marvell and
community.
I wrote it a few time ago to get the basic SDHC/MMC support into denx
u-boot, but the code is still buggy.
In my opinion, the mvsdio driver from Linux kernel might be ported to
denx to be mainline. I do not get it working for now...
The code for sdio driver from marvell u-boot was buggy and was just
ported without debugging.
It might work, might not.
The best method is to use NAND, USB stick are not fast enough and may be
broken also (I have a USB key drop unwritable after using it with a
sheevaplugs).
May be it is bug free now, with the latest git denx u-boot.
The IDE (SATA) for kirkwood from the git denx u-boot is now bugless and
fast enough to use in production with eSATA Sheevaplug and Kirkwood NAS
base.
---
DrEagle
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