Re: [U-Boot] Regarding revert of "Simplify RAM size detection" patch

Pe 10 feb. 2016 8:40 p.m., "Sam Protsenko" semen.protsenko@linaro.org a scris:

Hi guys,

Hi Sam,

I see that "Simplify RAM size detection" patch is reverted now. It was breaking boot on DRA7XX EVM as well. But I think I found the actual bug in that patch. This line (from patch):

•   for (cnt = (maxsize / sizeof(long)) >> 1; cnt > 0; cnt >>= 1) {
  

•   for (cnt = (maxsize / sizeof(long)) >> 1; cnt >= 0; cnt >>= 1) {
  
  

is changing loop condition to "cnt >= 0". And once cnt is 0, loop continue iterating, turning into forever loop. To fix this one can add "break" line here:

Yes, I got that part, see here:

http://lists.denx.de/pipermail/u-boot/2016-February/245080.html

The problem is that the bottom part still has an issue because the size is reported incorrectly even with the addendum.

    for (cnt = (maxsize / sizeof(long)) >> 1; cnt >= 0; cnt >>= 1) {
            addr = base + cnt;      /* pointer arith! */
            sync();
            save[i] = *addr;
            sync();
            if (cnt) {
                    i++;
                    *addr = ~cnt;
            } else {
                    *addr = 0;

•                   break;
            }
  
  

So if someone is going to rework it and push again -- this note can be

helpful.

Thanks, Eddy