* H. Nikolaus Schaller hns@goldelico.com [170907 04:23]:
Hi,
Am 07.09.2017 um 13:15 schrieb Michael Mrozek EvilDragon@openpandora.org:
Am Wed, 6 Sep 2017 22:05:38 -0700 hat Tony Lindgren tony@atomide.com geschrieben:
Hi,
nice! Is that with 1,35V as well?
for me it does not work (at least for 1.35V). U-Boot complains about non-existing RAM with this change right from the first power-on at room temperature.
Works for me at 1.35V, except u-boot is having hard time starting when host.
The interesting thing is about the cool down... I wonder if that works better when we have the cooling applied.
Maybe I should put it into a fridge to get U-Boot starting?
What's the u-boot commit you're using as base? I can try with that at some point later on my time today.
I'll build another unit with cooling and a 4GB board for testing.
Yes, that would be good!
Below is a more minimal version that just disables internal DLL on init. No idea why that helps, but it seems to be some kind of self-refresh clocking configuration issue.
Regards,
Tony
8< -------------------
From tony Mon Sep 17 00:00:00 2001
From: Tony Lindgren tony@atomide.com Date: Wed, 6 Sep 2017 21:42:01 -0700 Subject: [PATCH] Pyra/LC15: Disable DDR3 internall DLL to get 4GB working
I was wondering about the weird non-sensical 0xffff ref_ctrl and was thinking maybe we have multiple clocks going? And by setting ref_ctrl to 0xffff we stop their interaction for most part and this allowed me to boot kernel and run memtester..
Anyways, setting bit 20 to disable DDR3 internal DLL allowed me to remove the weird non-sensical 0xffff value for ref_ctrl. And further testing showed that this also allows removing the rest of the hacks as well and I can run two instances of memtester 1900M with Matthij's timings!
And from there we get to the point where the internal DLL only needs to be disabled for .sdram_config_init.
Note that the board needs to be let cool down before booting, otherwise you can get the "dq test failed" errors in u-boot. --- board/goldelico/letux-cortex15/lc15.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/board/goldelico/letux-cortex15/lc15.c b/board/goldelico/letux-cortex15/lc15.c --- a/board/goldelico/letux-cortex15/lc15.c +++ b/board/goldelico/letux-cortex15/lc15.c @@ -37,7 +37,7 @@ const struct omap_sysinfo sysinfo = { */
const struct emif_regs emif_regs_ddr3_532_mhz_2cs_es2 = { - .sdram_config_init = 0x61851B3A, + .sdram_config_init = 0x61951B3A, .sdram_config = 0x61851B3A, .sdram_config2 = 0x0, .ref_ctrl = 0x00001035,