On Nov 30, 2010, at 7:50 PM, Scott Wood wrote:
On Tue, 30 Nov 2010 18:36:25 -0600 Timur Tabi timur@freescale.com wrote:
@@ -244,8 +266,15 @@ void flash_write64(u64 value, void *addr)
/* There is no __raw_writeq(), so do the write manually */ *(volatile u64 *)addr = value;
- if (sw)
- if (sw) {
/** To ensure the post-write is completed to eLBC, software must* perform a dummy read from one valid address from eLBC space* before changing the eLBC_DIU from NOR mode to DIU mode.*/__raw_readb(addr);- }
Careful with the barriers.
You've got a raw readback, which means it's not going to wait for completion with the twi/isync hack.
Ordinarily that would be OK, since you only need ordering between the readb and the first access in set_mux_to_diu(). Unfortunately, that first access is an 8-bit access, which for some strange reason does sync differently than 16/32-bit accesses. The latter do sync+write, but 8-bit does write+eieio. So there's no barrier between the read and the write.
Any reason not to use in_8 here?
- k