6.6-stable review patch. If anyone has any objections, please let me know.
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From: Paul Fertser fercerpav@gmail.com
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 fercerpav@gmail.com Reviewed-by: Iwona Winiarska iwona.winiarska@intel.com Link: https://lore.kernel.org/r/20250123122003.6010-1-fercerpav@gmail.com Signed-off-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/hwmon/peci/dimmtemp.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)
--- a/drivers/hwmon/peci/dimmtemp.c +++ b/drivers/hwmon/peci/dimmtemp.c @@ -127,8 +127,6 @@ static int update_thresholds(struct peci 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
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
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