[PATCH] EDAC/amd64: Fix possible module load failure on some UMC usage combinations

From: Avadhut Naik
Date: Mon Dec 09 2024 - 16:56:55 EST


Starting Zen4, AMD SOCs have 12 Unified Memory Controllers (UMCs) per
socket.

When the amd64_edac module is being loaded, these UMCs are traversed to
determine if they have SdpInit (SdpCtrl[31]) and EccEnabled (UmcCapHi[30])
bits set and create masks in umc_en_mask and ecc_en_mask respectively.

However, the current data type of these variables is u8. As a result, if
only the last 4 UMCs (UMC8 - UMC11) of the system have been utilized,
umc_ecc_enabled() will return false. Consequently, the module may fail to
load on these systems.

Change the data type of these variables to u16.

Signed-off-by: Avadhut Naik <avadhut.naik@xxxxxxx>
---
drivers/edac/amd64_edac.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index ddfbdb66b794..583685e8e60f 100644
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -3362,7 +3362,7 @@ static bool dct_ecc_enabled(struct amd64_pvt *pvt)

static bool umc_ecc_enabled(struct amd64_pvt *pvt)
{
- u8 umc_en_mask = 0, ecc_en_mask = 0;
+ u16 umc_en_mask = 0, ecc_en_mask = 0;
u16 nid = pvt->mc_node_id;
struct amd64_umc *umc;
u8 ecc_en = 0, i;
--
2.43.0