From bf92b19b2a234d63d88fea6bd55ad83361e18574 Mon Sep 17 00:00:00 2001 From: Hung-Te Lin Date: Mon, 29 Apr 2013 22:11:22 +0800 Subject: [PATCH] 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 Reviewed-on: http://review.coreboot.org/3148 Reviewed-by: Paul Menzel Tested-by: build bot (Jenkins) Reviewed-by: Ronald G. Minnich --- 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 f131e81c8f..aa3a3405e3 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"); }