[U-Boot] IS_ERR_VALUE failing on socfpga gen5

[Simon Glass]

Hi Simon,

On Tue, 8 Oct 2019 at 14:34, Simon Goldschmidt
<simon.k.r.goldschmidt at gmail.com> wrote:
>
> In a series I'm currently preparing, I've stumbled accross the fact that
> IS_ERR_VALUE() doesn't reliably work on socfpga SPL as the onchip SRAM
> begins at 0xffff0000 and the heap is at the end of the 32 bit range.
>

Which function is returning that address?

> Being like that, the current test for error (value >= -4095) which
> equals 'value >= 0xfffff001' would require us to waste the last 4K of
> that memory, which is not an option when it comes to using DM in SPL...
>
> Now on this platform, I'm sure I could find a range of 4096 bytes to use
> as invalid pointer range, but the question is: how do I integrate that
> into U-Boot in a clean manner? Would it be acceptable to change the
> error headers imported from Linux or would I have to through the hassle
> of changing Linux first?
>
> Or does anyone have a better idea to allow using the last 4K for heap?

Regards,
Simon