[PATCH v2] EDAC/i10nm: Don't fail probing if ADXL is missing

[Vasily Khoruzhick]

From: Vasily Khoruzhick <vasilykh@xxxxxxxxxx>

ADXL is not present in Coreboot- or Slimbootloader-based BIOSes and as
result, the driver fails to probe there.

Since commit 2738c69a8813 ("EDAC/i10nm: Add driver decoder for Ice Lake
and Tremont CPUs"), i10nm_edac supports driver decoder. Switch to driver
decoding when ADXL is not present.

Cc: stable@xxxxxxxxxxxxxxx # v6.1+
Reviewed-by: Qiuxu Zhuo <qiuxu.zhuo@xxxxxxxxx>
Signed-off-by: Vasily Khoruzhick <vasilykh@xxxxxxxxxx>
---
v2: - use imperative tone in commit message
    - add r-b tag

 drivers/edac/i10nm_base.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/edac/i10nm_base.c b/drivers/edac/i10nm_base.c
index 89b3e8cc38b1..69a4a255e4c8 100644
--- a/drivers/edac/i10nm_base.c
+++ b/drivers/edac/i10nm_base.c
@@ -79,6 +79,7 @@ static struct res_config *res_cfg;
 static int retry_rd_err_log;
 static int decoding_via_mca;
 static bool mem_cfg_2lm;
+static bool no_adxl;
 
 static struct reg_rrl icx_reg_rrl_ddr = {
 	.set_num = 2,
@@ -1208,8 +1209,14 @@ static int __init i10nm_init(void)
 	}
 
 	rc = skx_adxl_get();
-	if (rc)
-		goto fail;
+	if (rc) {
+		/* Decoding errors via MCA banks for 2LM isn't supported yet */
+		if (rc != -ENODEV || mem_cfg_2lm)
+			goto fail;
+		i10nm_printk(KERN_INFO, "ADXL not found, falling back to MCA-based decoding.\n");
+		no_adxl = true;
+		decoding_via_mca = true;
+	}
 
 	opstate_init();
 	mce_register_decode_chain(&i10nm_mce_dec);
@@ -1243,7 +1250,8 @@ static void __exit i10nm_exit(void)
 
 	skx_teardown_debug();
 	mce_unregister_decode_chain(&i10nm_mce_dec);
-	skx_adxl_put();
+	if (!no_adxl)
+		skx_adxl_put();
 	skx_remove();
 }
 
-- 
2.53.0