Patch set updated for coreboot: nb/intel/sandybridge/raminit: add additional fallbacks

[Patrick Rudolph]

Patrick Rudolph ([e-mail]) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/14173

-gerrit

commit 29f99886c7b3d4fa91790b944a18da054fba6d85
Author: Patrick Rudolph 
Date:   Sat Mar 26 12:16:29 2016 +0100

nb/intel/sandybridge/raminit: add additional fallbacks

Add the following fallbacks:
    * Try decreasing clock frequency.
       In case of DDR1600 the next possible value of DDR1333 is being used.
    * Try decreasing clock frequency.
       In case of DDR1333 the next possible value of DDR1066 is being used.
    * Disable failing channel.
       The system may be able to boot with a single channel enabled.

The fallbacks are untested.

Change-Id: I3be7034ad25312b3ebf47a54f335a3893f8d7cc1
    Signed-off-by: Patrick Rudolph 
---
 src/northbridge/intel/sandybridge/raminit.c | 45 +++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/src/northbridge/intel/sandybridge/raminit.c b/src/northbridge/intel/sandybridge/raminit.c
index b980ff8..f6d082f 100644
--- a/src/northbridge/intel/sandybridge/raminit.c
+++ b/src/northbridge/intel/sandybridge/raminit.c
@@ -201,6 +201,7 @@ typedef struct ramctr_timing_st {
 #define MAX_TIMA 127

#define MAKE_ERR ((channel<<16)|(slotrank<<8)|1)
+#define GET_ERR_CHANNEL(x) (x>>16)

static void program_timings(ramctr_timing * ctrl, int channel);

@@ -241,6 +242,18 @@ static void toggle_io_reset(void) {
 }

/*
+ * Disable a channel in ramctr_timing.
+ */
+static void disable_channel(ramctr_timing *ctrl, int channel) {
+	ctrl->rankmap[channel] = 0;
+	memset(&ctrl->rank_mirror[channel][0], 0, sizeof(ctrl->rank_mirror[0]));
+	ctrl->channel_size_mb[channel] = 0;
+	ctrl->cmd_stretch[channel] = 0;
+	ctrl->mad_dimm[channel] = 0;
+	memset(&ctrl->timings[channel][0], 0, sizeof(ctrl->timings[0]));
+}
+
+/*
  * Fill cbmem with information for SMBIOS type 17.
  */
 static void fill_smbios17(ramctr_timing *ctrl)
@@ -4242,6 +4255,38 @@ void init_dram_ddr3(spd_raw_data *spds, int mobile, int min_tck,
    }

err = try_init_dram_ddr3(&ctrl, fast_boot, me_uma_size);
+	if (!err)
+		goto done;
+
+	/* fallback: lower clock frequency */
+	printk(BIOS_ERR, "RAM training failed, trying fallback.\n");
+	printram("Decreasing clock frequency.\n");
+	ctrl.tCK++;
+
+	err = try_init_dram_ddr3(&ctrl, fast_boot, me_uma_size);
+	if (!err)
+		goto done;
+
+	/* fallback: lower clock frequency */
+	printk(BIOS_ERR, "RAM training failed, trying fallback.\n");
+	printram("Decreasing clock frequency.\n");
+	ctrl.tCK++;
+
+	err = try_init_dram_ddr3(&ctrl, fast_boot, me_uma_size);
+	if (!err)
+		goto done;
+
+	/* fallback: disable failing channel */
+	printk(BIOS_ERR, "RAM training failed, trying fallback.\n");
+	printram("Disable failing channel.\n");
+
+	/* Reset DDR3 frequency */
+	dram_find_spds_ddr3(spds, &ctrl);
+
+	/* disable failing channel */
+	disable_channel(&ctrl, GET_ERR_CHANNEL(err));
+
+	err = try_init_dram_ddr3(&ctrl, fast_boot, me_uma_size);
    if (err)
    	die("raminit failed");