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Commit d7ce0335b5ddbe4cc1c519750074b5176a4124ab

Authored by Jean Delvare
Committed by Jean Delvare
1 parent 177e75925b
Exists in master and in 7 other branches imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

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: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com>

Showing 2 changed files with 20 additions and 19 deletions Side-by-side Diff

Documentation/hwmon/adm1021
Diff comments   View file @ d7ce033
... ... @@ -14,10 +14,6 @@
14 14 Prefix: 'gl523sm'
15 15 Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
16 16 Datasheet:
17   - * Intel Xeon Processor
18   - Prefix: - any other - may require 'force_adm1021' parameter
19   - Addresses scanned: none
20   - Datasheet: Publicly available at Intel website
21 17 * Maxim MAX1617
22 18 Prefix: 'max1617'
23 19 Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
24 20  
25 21  
26 22  
27 23  
28 24  
... ... @@ -91,22 +87,28 @@
91 87 ADM1021-clones do faster measurements, but there is really no good reason
92 88 for that.
93 89  
94   -Xeon support
95   -------------
96 90  
97   -Some Xeon processors have real max1617, adm1021, or compatible chips
98   -within them, with two temperature sensors.
  91 +Netburst-based Xeon support
  92 +---------------------------
99 93  
100   -Other Xeons have chips with only one sensor.
  94 +Some Xeon processors based on the Netburst (early Pentium 4, from 2001 to
  95 +2003) microarchitecture had real MAX1617, ADM1021, or compatible chips
  96 +within them, with two temperature sensors. Other Xeon processors of this
  97 +era (with 400 MHz FSB) had chips with only one temperature sensor.
101 98  
102   -If you have a Xeon, and the adm1021 module loads, and both temperatures
103   -appear valid, then things are good.
  99 +If you have such an old Xeon, and you get two valid temperatures when
  100 +loading the adm1021 module, then things are good.
104 101  
105   -If the adm1021 module doesn't load, you should try this:
106   - modprobe adm1021 force_adm1021=BUS,ADDRESS
107   - ADDRESS can only be 0x18, 0x1a, 0x29, 0x2b, 0x4c, or 0x4e.
  102 +If nothing happens when loading the adm1021 module, and you are certain
  103 +that your specific Xeon processor model includes compatible sensors, you
  104 +will have to explicitly instantiate the sensor chips from user-space. See
  105 +method 4 in Documentation/i2c/instantiating-devices. Possible slave
  106 +addresses are 0x18, 0x1a, 0x29, 0x2b, 0x4c, or 0x4e. It is likely that
  107 +only temp2 will be correct and temp1 will have to be ignored.
108 108  
109   -If you have dual Xeons you may have appear to have two separate
110   -adm1021-compatible chips, or two single-temperature sensors, at distinct
111   -addresses.
  109 +Previous generations of the Xeon processor (based on Pentium II/III)
  110 +didn't have these sensors. Next generations of Xeon processors (533 MHz
  111 +FSB and faster) lost them, until the Core-based generation which
  112 +introduced integrated digital thermal sensors. These are supported by
  113 +the coretemp driver.
drivers/hwmon/Kconfig
Diff comments   View file @ d7ce033
... ... @@ -110,8 +110,7 @@
110 110 help
111 111 If you say yes here you get support for Analog Devices ADM1021
112 112 and ADM1023 sensor chips and clones: Maxim MAX1617 and MAX1617A,
113   - Genesys Logic GL523SM, National Semiconductor LM84, TI THMC10,
114   - and the XEON processor built-in sensor.
  113 + Genesys Logic GL523SM, National Semiconductor LM84 and TI THMC10.
115 114  
116 115 This driver can also be built as a module. If so, the module
117 116 will be called adm1021.