Commit d7ce0335 authored by Jean Delvare's avatar Jean Delvare Committed by Jean Delvare

hwmon: (adm1021) Clarify documentation regarding Xeon processors

Recent Xeon processor thermal sensors are supported by the coretemp
driver and not the adm1021 driver. Only one old generation of Xeon
processors (the first Netburst ones) are supported by the adm1021
driver.
Reported-by: default avatarDarren Hart <dvhart@linux.intel.com>
Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
Acked-by: default avatarGuenter Roeck <guenter.roeck@ericsson.com>
parent 177e7592
...@@ -14,10 +14,6 @@ Supported chips: ...@@ -14,10 +14,6 @@ Supported chips:
Prefix: 'gl523sm' Prefix: 'gl523sm'
Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
Datasheet: Datasheet:
* Intel Xeon Processor
Prefix: - any other - may require 'force_adm1021' parameter
Addresses scanned: none
Datasheet: Publicly available at Intel website
* Maxim MAX1617 * Maxim MAX1617
Prefix: 'max1617' Prefix: 'max1617'
Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
...@@ -91,21 +87,27 @@ will do no harm, but will return 'old' values. It is possible to make ...@@ -91,21 +87,27 @@ will do no harm, but will return 'old' values. It is possible to make
ADM1021-clones do faster measurements, but there is really no good reason ADM1021-clones do faster measurements, but there is really no good reason
for that. for that.
Xeon support
------------
Some Xeon processors have real max1617, adm1021, or compatible chips Netburst-based Xeon support
within them, with two temperature sensors. ---------------------------
Other Xeons have chips with only one sensor. Some Xeon processors based on the Netburst (early Pentium 4, from 2001 to
2003) microarchitecture had real MAX1617, ADM1021, or compatible chips
within them, with two temperature sensors. Other Xeon processors of this
era (with 400 MHz FSB) had chips with only one temperature sensor.
If you have a Xeon, and the adm1021 module loads, and both temperatures If you have such an old Xeon, and you get two valid temperatures when
appear valid, then things are good. loading the adm1021 module, then things are good.
If the adm1021 module doesn't load, you should try this: If nothing happens when loading the adm1021 module, and you are certain
modprobe adm1021 force_adm1021=BUS,ADDRESS that your specific Xeon processor model includes compatible sensors, you
ADDRESS can only be 0x18, 0x1a, 0x29, 0x2b, 0x4c, or 0x4e. will have to explicitly instantiate the sensor chips from user-space. See
method 4 in Documentation/i2c/instantiating-devices. Possible slave
addresses are 0x18, 0x1a, 0x29, 0x2b, 0x4c, or 0x4e. It is likely that
only temp2 will be correct and temp1 will have to be ignored.
If you have dual Xeons you may have appear to have two separate Previous generations of the Xeon processor (based on Pentium II/III)
adm1021-compatible chips, or two single-temperature sensors, at distinct didn't have these sensors. Next generations of Xeon processors (533 MHz
addresses. FSB and faster) lost them, until the Core-based generation which
introduced integrated digital thermal sensors. These are supported by
the coretemp driver.
...@@ -110,8 +110,7 @@ config SENSORS_ADM1021 ...@@ -110,8 +110,7 @@ config SENSORS_ADM1021
help help
If you say yes here you get support for Analog Devices ADM1021 If you say yes here you get support for Analog Devices ADM1021
and ADM1023 sensor chips and clones: Maxim MAX1617 and MAX1617A, and ADM1023 sensor chips and clones: Maxim MAX1617 and MAX1617A,
Genesys Logic GL523SM, National Semiconductor LM84, TI THMC10, Genesys Logic GL523SM, National Semiconductor LM84 and TI THMC10.
and the XEON processor built-in sensor.
This driver can also be built as a module. If so, the module This driver can also be built as a module. If so, the module
will be called adm1021. will be called adm1021.
......
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