From e09b750526210775287c52d57b5ee2494847f5ed Mon Sep 17 00:00:00 2001 From: Armin Wolf Date: Thu, 7 Sep 2023 07:26:39 +0200 Subject: [PATCH] hwmon: (sch5627) Document behaviour of limit registers The values of the limit registers affect the fan speed in a particular way. Document this behaviour so that future users can exploit it if required. Signed-off-by: Armin Wolf Link: https://lore.kernel.org/r/20230907052639.16491-6-W_Armin@gmx.de Signed-off-by: Guenter Roeck --- Documentation/hwmon/sch5627.rst | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/Documentation/hwmon/sch5627.rst b/Documentation/hwmon/sch5627.rst index ecb4fc84d045..8639dff234fc 100644 --- a/Documentation/hwmon/sch5627.rst +++ b/Documentation/hwmon/sch5627.rst @@ -33,3 +33,13 @@ The hardware monitoring part of the SMSC SCH5627 is accessed by talking through an embedded microcontroller. An application note describing the protocol for communicating with the microcontroller is available upon request. Please mail me if you want a copy. + + +Controlling fan speed +--------------------- + +The SCH5627 allows for partially controlling the fan speed. If a temperature +channel excedes tempX_max, all fans are forced to maximum speed. The same is not +true for tempX_crit, presumably some other measures to cool down the system are +take in this case. +In which way the value of fanX_min affects the fan speed is currently unknown.