[U-Boot-Users] [PATCH] Fixed cfi flash read uchar bug.

Wolfgang Denk wd at denx.de
Thu Jan 4 10:23:31 CET 2007

In message <46B96294322F7D458F9648B60E15112C03EEE0 at zch01exm26.fsl.freescale.net> you wrote:
> The below is the previous email:
> Wolfgang Denk wrote:
> > Now this is what I want to understand. What exactly is the "potential
> > problem"?
> That's the issue in the flash 'Spinsion S29GL064M90TFIR6' with x16 
> connection. After running flash_read_jedec_ids(), any follow CFI query 
> command will get the data with high 8bit = 0xff, but the low 8bit is 
> valid. And if we only read low 8bit, we'll get the 0xff too. In 
> addition, the second follow CFI query command has no that issue. So, I 
> read the full 16bit date and only take the valid low 8bit.

etc. etc.

I didn't see any new facts in your current posting. My  position  has
not  changed  either:  I don't see how your character-wise copy using
memcpy() would be different from accessing the flash through a  uchar
pointer;  also  I  still  think  that if the compiler version changes
behaviour then we don't really understand what's going on here.

Maybe Tolunay or Stefan can comment now that both are back from their
Xmas breaks; they both know the CFI driver much better than me.

I tend to reject your proposed patch until we really understand the
problem. To me, the patch seems to be wrong.

Best regards,

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Unix is like a toll road on which you have to stop every 50  feet  to
pay another nickel. But hey! You only feel 5 cents poorer each time.
                 - Larry Wall in <1992Aug13.192357.15731 at netlabs.com>

More information about the U-Boot mailing list