On Mon, Mar 29, 2010 at 5:09 PM, Becky Bruce <bec...@kernel.crashing.org> wrote:
>> --- a/board/freescale/mpc8641hpcn/mpc8641hpcn.c >> +++ b/board/freescale/mpc8641hpcn/mpc8641hpcn.c >> @@ -72,6 +72,8 @@ initdram(int board_type) >> dram_size = fixed_sdram(); >> #endif >> >> + adjust_ddr_bat(dram_size); >> + > > By doing this here, you still have a (small) window where the problem > could occur. U-Boot hasn't relocated yet, so it's not using any of the DDR. I don't see how there could be a problem. > It's highly unlikely, but we might still have problems > going forward. I think we might need to: > > 1) remove the write of BAT0 from setup_bats (add a comment). This > way, there is no BAT setup for the DDR until right after we configure > the controller Ok, I get it now. It will catch anyone trying to write to DDR before it's really set up. I can do that. > 2) change the name "adjust_ddr_bat" to "setup_ddr_bat" or something > similar. I haven't dug around too much to see if this causes > problems, but I am able to boot my 8641 this way. Ok. > 3) Change setup_ddr_bat so that it just does a write (remove the BL > from the #defined values for the default BAT0 and or them in here > instead, and add a comment to the config file that says BL is > determined dynamically Ok. > I think you need to adjust how much usable ram u-boot thinks it has if > you can't map it all. I tried that. The problem is that U-Boot uses this number to tell Linux how much DDR there is. The code doesn't really support U-Boot and Linux seeing different amounts of DDR. > If you have one BAT, and you have an amount of > memory that is ! a power of 2, then you're going to leave a chunk > unmapped, which can cause problems later. AFAIK, we always have only one BAT for DDR. I wasn't planning on expanding the scope of this patch to add support for multiple BATs. I don't know how to handle !2^X sizes of DDR. >> +#define KB_TO_BATU(x) ((((x)/128) - 1) * 4) /* Convert KBs to BATU >> value */ > > It seems somewhat arbitrary that you decided to use take KB here as an > arg when the BATU_SIZE macro returns bytes. I'd prefer to see > symmetry here. I used KB to keep the sizes of numbers small. The smallest value is 128KB, so it's not *that* arbitrary. -- Timur Tabi Linux kernel developer at Freescale _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
