Thread (10 messages) 10 messages, 5 authors, 2009-05-28

Re: Weird 5200/mtd-ram problem

From: Albrecht Dreß <hidden>
Date: 2009-05-20 19:36:56

Am 20.05.09 16:23 schrieb(en) Gary Thomas:
quoted
In Linux, when I write the file to /dev/mtdx, the last dword of  
each block is broken, e.g. when running "dd if=pattern of=/dev/mtd5  
bs=512" the dword's at offset 0x1fc, 0x3fc, ... are 0x0000aaaa  
(instead of 0x0055aaff), if I use bs=1024 the dwords at 0x3fc, 0x7fc,  
... show this value, if I use bs=4096 the dword at 0xffc shows this  
value, etc.  I looked at the CS/WR lines with a scope, and I couldn't  
see anything special.  The timing should be fine, as u-boot uses the  
same as Linux.
quoted
Any idea what goes wrong here?  I guessed I missed something in the  
LPB setup...

Check your cache setup - the BDI is most certainly not accessing this  
via the Data cache whereas Linux probably will be.
Hmm, yes - I didn't touch the vanilla Lite5200B Linux setup there,  
which has a flash chip at cs1...

If it is really a cache problem (I'm away now from my test board) -  
isn't a sync sufficient after doing the copy to the external ram  
(lpb/cs1)?  What is the proper approach for devices attached to the  
localbus?

Thanks, Albrecht.

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