Wolfgang Denk wrote:
Dear "Michele De Candia (VT)",
In message 4A37F7BF.2090101@valueteam.com you wrote:
this patch fixes a bug for 'nand erase' command: when bad blocks are present into erasing area, they were skipped but the erased size was updated anyway.
And what exactly is the bug in this behaviour?
I think that 'erase' should have the same behaviour of 'write' and 'read' commands: skip bad blocks until read/write size is reached. If you write a script that erases and then writes a NAND area and bad blocks are not skipped while erasing (as U-Boot actually does), the following 'write' is successfully done but ECC checks fail on next read on the same area.
I see - thanks for the explanation.
Hm... actually I think the write should fail in such a case...
Scott, what do you think?
I think the current behavior is reasonable. You're erasing a specific region of flash, not an amount needed to hold a certain amount of data.
While I can see the appeal of Michele's suggestion, I think it would be more error-prone as people trying to erase a region rather than just the size of data could erase too much.
It definitely should not be an error to erase a region that happens to contain a bad block. Bad blocks are expected and we need to work around them.
-Scott