[coreboot-gerrit] Patch set updated for coreboot: 666048e Google/Snow: Temporary fix for resume failure.

[Hung-Te Lin (hungte@chromium.org)]

Hung-Te Lin (hungte at chromium.org) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/3148

-gerrit

commit 666048e61c3a70adc298ad10a4cf372b5662f3c3
Author: Hung-Te Lin <hungte at chromium.org>
Date:   Mon Apr 29 22:11:22 2013 +0800

    Google/Snow: Temporary fix for resume failure.
    
    The DDR3 memory initialization (with "mem_reset" set on normal boot) will cause
    resume to be unstable, especially when X is running. System may show X screen
    for few seconds, then crash randomly and unable to recover - although text
    console may still work for a while.  Probably caused by corrupted memory pages.
    
    'mem_reset' (which refers to RESET# in DDR3 spec) should be enabled according
    to DDR3 spec. But it seems that on Exynos 5, memory can be initialized without
    setting mem_reset for both normal boot and resume - at least no known failure
    cases are found yet.  So this can be a temporary workaround.
    
    Verified by booting a Google/Snow device with X Window and ChromeOS, entering
    browser session with fancy web pages, closing LID to suspend for 5 seconds, then
    re-opening to resume.  Suspend/resume worked as expected.
    
    Also tried the "suspend_stress_test" with X running and finished 100 iterations
    of suspend/resume test without failure.
    
    Change-Id: I7185b362ce8b545fe77b35a552245736c89d465e
    Signed-off-by: Hung-Te Lin <hungte at chromium.org>
---
 src/mainboard/google/snow/romstage.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/mainboard/google/snow/romstage.c b/src/mainboard/google/snow/romstage.c
index f131e81..aa3a340 100644
--- a/src/mainboard/google/snow/romstage.c
+++ b/src/mainboard/google/snow/romstage.c
@@ -150,6 +150,14 @@ static void snow_setup_memory(struct mem_timings *mem, int is_resume)
 	       mem->mem_type,
 	       mem->mpll_mdiv,
 	       mem->frequency_mhz);
+
+	/* FIXME Currently memory initialization with mem_reset on normal boot
+	 * will cause resume to fail (even if we don't do mem_reset on resume),
+	 * and the workaround is to temporarily always enable "is_resume".
+	 * This should be removed when the root cause of resume issue is found.
+	 */
+	is_resume = 1;
+
 	if (ddr3_mem_ctrl_init(mem, DMC_INTERLEAVE_SIZE, !is_resume)) {
 		die("Failed to initialize memory controller.\n");
 	}