[REGRESSION] hwmon: (applesmc) avoid overlong udelay()

Andreas Kemnade
2020-09-30T08:54:52Z

Hi,

after the $subject patch I get lots of errors like this:
[ 120.378614] applesmc: send_byte(0x00, 0x0300) fail: 0x40
[ 120.378621] applesmc: LKSB: write data fail
[ 120.512782] applesmc: send_byte(0x00, 0x0300) fail: 0x40
[ 120.512787] applesmc: LKSB: write data fail

CPU sticks at low speed and no fan is turning on.
Reverting this patch on top of 5.9-rc6 solves this problem.

Some information from dmidecode:

Base Board Information
Manufacturer: Apple Inc.
Product Name: Mac-7DF21CB3ED6977E5
Version: MacBookAir6,2

Handle 0x0020, DMI type 11, 5 bytes OEM Strings String 1: Apple ROM Version. Model: …,
Handle 0x0020, DMI type 11, 5 bytes
OEM Strings
String 1: Apple ROM Version. Model: MBA61. EFI Version: 122.0.0
String 2: .0.0. Built by: root@saumon. Date: Wed Jun 10 18:
String 3: 10:36 PDT 2020. Revision: 122 (B&I). ROM Version: F000_B
String 4: 00. Build Type: Official Build, Release. Compiler: Appl
String 5: e clang version 3.0 (tags/Apple/clang-211.10.1) (based on LLVM
String 6: 3.0svn).

Writing to things in /sys/devices/platform/applesmc.768 gives also the
said errors.
But writing 1 to fan1_maunal and 5000 to fan1_output turns the fan on
despite error messages.

Config used is: https://misc.andi.de1.cc/mac-config.gz

Regards,
Andreas