From 3e92d62d9534edb31fdb1f5c115ecebf24fb93ea Mon Sep 17 00:00:00 2001 From: Paul Fertser Date: Thu, 23 Jan 2025 15:20:02 +0300 Subject: [PATCH] hwmon: (peci/dimmtemp) Do not provide fake thresholds data commit 5797c04400ee117bfe459ff1e468d0ea38054ab4 upstream. When an Icelake or Sapphire Rapids CPU isn't providing the maximum and critical thresholds for particular DIMM the driver should return an error to the userspace instead of giving it stale (best case) or wrong (the structure contains all zeros after kzalloc() call) data. The issue can be reproduced by binding the peci driver while the host is fully booted and idle, this makes PECI interaction unreliable enough. Fixes: 73bc1b885dae ("hwmon: peci: Add dimmtemp driver") Fixes: 621995b6d795 ("hwmon: (peci/dimmtemp) Add Sapphire Rapids support") Cc: stable@vger.kernel.org Signed-off-by: Paul Fertser Reviewed-by: Iwona Winiarska Link: https://lore.kernel.org/r/20250123122003.6010-1-fercerpav@gmail.com Signed-off-by: Guenter Roeck Signed-off-by: Greg Kroah-Hartman --- drivers/hwmon/peci/dimmtemp.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/drivers/hwmon/peci/dimmtemp.c b/drivers/hwmon/peci/dimmtemp.c index 4a72e9712408e..b7b09780c7b0a 100644 --- a/drivers/hwmon/peci/dimmtemp.c +++ b/drivers/hwmon/peci/dimmtemp.c @@ -127,8 +127,6 @@ static int update_thresholds(struct peci_dimmtemp *priv, int dimm_no) return 0; ret = priv->gen_info->read_thresholds(priv, dimm_order, chan_rank, &data); - if (ret == -ENODATA) /* Use default or previous value */ - return 0; if (ret) return ret; @@ -509,11 +507,11 @@ read_thresholds_icx(struct peci_dimmtemp *priv, int dimm_order, int chan_rank, u ret = peci_ep_pci_local_read(priv->peci_dev, 0, 13, 0, 2, 0xd4, ®_val); if (ret || !(reg_val & BIT(31))) - return -ENODATA; /* Use default or previous value */ + return -ENODATA; ret = peci_ep_pci_local_read(priv->peci_dev, 0, 13, 0, 2, 0xd0, ®_val); if (ret) - return -ENODATA; /* Use default or previous value */ + return -ENODATA; /* * Device 26, Offset 224e0: IMC 0 channel 0 -> rank 0 @@ -546,11 +544,11 @@ read_thresholds_spr(struct peci_dimmtemp *priv, int dimm_order, int chan_rank, u ret = peci_ep_pci_local_read(priv->peci_dev, 0, 30, 0, 2, 0xd4, ®_val); if (ret || !(reg_val & BIT(31))) - return -ENODATA; /* Use default or previous value */ + return -ENODATA; ret = peci_ep_pci_local_read(priv->peci_dev, 0, 30, 0, 2, 0xd0, ®_val); if (ret) - return -ENODATA; /* Use default or previous value */ + return -ENODATA; /* * Device 26, Offset 219a8: IMC 0 channel 0 -> rank 0 -- 2.47.3