Re: [U-Boot] [PATCH] arm: Kirkwood: Add memory barriers to kwgbe_send/recv

Hi Simon,

Add memory barriers to kwgbe_send/recv

kwgbe_send/recv both have loops waiting for the hardware to set a bit. GCC 4.3.3 cleverly optimizes this to ... a while(1); loop. This patch introduces memory barriers to force re-loading of the transmit descriptor.

mb() wasn't defined for arm, but perhaps it should?

You should rather use read/write accessor macros which "do the right thing". Try using readl() for the loop. Memory barriers do not belong into "upper level" code.

Cheers Detlev