[S] Change in coreboot[master]: nb/intel/i945: Check if channel 0 and 1 are populated

[Elyes Haouas (Code Review)]

Elyes Haouas has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/68781 )

Change subject: nb/intel/i945: Check if channel 0 and 1 are populated
......................................................................

nb/intel/i945: Check if channel 0 and 1 are populated

Even if the system support dual operation, set 'sysinfo->dual_channel'
to true only if channel 0 and 1 are populated.
Use 'sysinfo->dual_channel' for 'sdram_rcomp_buffer_strength_and_slew()'.

Change-Id: Ia77861e5f44501b5d92707977597e143b439e9d4
Signed-off-by: Elyes Haouas 
---
M src/northbridge/intel/i945/raminit.c
1 file changed, 24 insertions(+), 6 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/81/68781/1

diff --git a/src/northbridge/intel/i945/raminit.c b/src/northbridge/intel/i945/raminit.c
index 2613b81..86bd689 100644
--- a/src/northbridge/intel/i945/raminit.c
+++ b/src/northbridge/intel/i945/raminit.c
@@ -293,6 +293,8 @@
    int i, j;
    u8 raw_spd[SPD_SIZE_MAX_DDR2];
    u8 dimm_mask = 0;
+	bool channel0_populated = false;
+	bool channel1_populated = false;

memset(saved_timings, 0, sizeof(*saved_timings));
    saved_timings->max_tRR = UINT32_MAX;
@@ -314,10 +316,8 @@

printk(BIOS_DEBUG, "This mainboard supports ");
    if (sdram_capabilities_dual_channel()) {
-		sysinfo->dual_channel = true;
    	printk(BIOS_DEBUG, "Dual Channel Operation.\n");
    } else {
-		sysinfo->dual_channel = false;
    	printk(BIOS_DEBUG, "only Single Channel Operation.\n");
    }

@@ -462,6 +462,12 @@
    if (!(dimm_mask & ((1 << DIMM_SOCKETS) - 1)))
    	/* FIXME: Possibly does not boot in this case */
    	printk(BIOS_INFO, "Channel 0 has no memory populated.\n");
+
+	if (dimm_mask & ((1 << DIMM_SOCKETS) - 1))
+		channel0_populated = true;
+	if (dimm_mask >> DIMM_SOCKETS & ((1 << DIMM_SOCKETS) - 1))
+		channel1_populated = true;
+	sysinfo->dual_channel = channel0_populated & channel1_populated;
 }

static void choose_tclk(struct sys_info *sysinfo, struct timings *saved_timings)
@@ -904,20 +910,18 @@
 {
    const u8 *strength_multiplier;
    int idx;
-	bool dual_channel;
+	bool dual_channel = sysinfo->dual_channel;

/* Set Strength Multipliers */

/* Dual Channel needs different tables. */
-	if (sdram_capabilities_dual_channel()) {
+	if (dual_channel) {
    	printk(BIOS_DEBUG, "Programming Dual Channel RCOMP\n");
    	strength_multiplier = dual_channel_strength_multiplier;
-		dual_channel = true;
    	idx = 5 * sysinfo->dimm[0] + sysinfo->dimm[2];
    } else {
    	printk(BIOS_DEBUG, "Programming Single Channel RCOMP\n");
    	strength_multiplier = single_channel_strength_multiplier;
-		dual_channel = false;
    	idx = 5 * sysinfo->dimm[0] + sysinfo->dimm[1];
    }