soc/mediatek/mt8183: Handle memory test failure

If DRAM calibration fails or mem test fails using the cached calibration
results stored in flash, rerun DRAM full calibration. If partial
calibration fails or the mem test following it fails, hang forever.

Partial calibration acts as a fallback approach in case of full
calibration failure. Therefore, if it fails, there would be no other
ways to initialize DRAM. Instead of falling into reboot loop and
draining out of battery, it is better to just hang so that the end user
may notice that and send to RMA.

BUG=b:80501386,b:139099592
BRANCH=kukui
TEST=Boots correctly on Kukui

Change-Id: I8e1d4f5bc7b45f45a8bfef74e86ec0ff6a556af4
Signed-off-by: Huayang Duan <huayang.duan@mediatek.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/35481
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 8 insertions, 4 deletions

diff --git a/src/soc/mediatek/mt8183/emi.c b/src/soc/mediatek/mt8183/emi.c
index 52baeb1688..4b08a10c08 100644
--- a/src/soc/mediatek/mt8183/emi.c
+++ b/src/soc/mediatek/mt8183/emi.c
@@ -342,12 +342,14 @@ void enable_emi_dcm(void)
 		clrbits_le32(&ch[chn].emi.chn_conb, 0xff << 24);
 }
 
-static void do_calib(const struct sdram_params *params, u8 freq_group)
+static int do_calib(const struct sdram_params *params, u8 freq_group)
 {
 	dramc_show("Start K, current clock is:%d\n", params->frequency);
-	dramc_calibrate_all_channels(params, freq_group);
+	if (dramc_calibrate_all_channels(params, freq_group) != 0)
+		return -1;
 	dramc_ac_timing_optimize(freq_group);
 	dramc_show("K finish with clock:%d\n", params->frequency);
+	return 0;
 }
 
 static void after_calib(void)
@@ -356,7 +358,7 @@ static void after_calib(void)
 	dramc_runtime_config();
 }
 
-void mt_set_emi(const struct dramc_param *dparam)
+int mt_set_emi(const struct dramc_param *dparam)
 {
 	const u8 *freq_tbl;
 	const int shuffle = DRAM_DFS_SHUFFLE_1;
@@ -372,7 +374,9 @@ void mt_set_emi(const struct dramc_param *dparam)
 	params = &dparam->freq_params[shuffle];
 
 	init_dram(params, current_freqsel);
-	do_calib(params, current_freqsel);
+	if (do_calib(params, current_freqsel) != 0)
+		return -1;
 
 	after_calib();
+	return 0;
 }