linux/drivers/platform
Mark Pearson bf779aaf56 platform/x86: thinkpad_acpi: Add dual fan probe
Instead of having quirks for systems that have a second fan it would
be nice to detect this setup.
Unfortunately, confirmed by the Lenovo FW team, there is no way to
retrieve this information from the EC or BIOS. Recommendation was to
attempt to read the fan and if successful then assume a 2nd fan is
present.

The fans are also supposed to spin up on boot for some time, so in
theory we could check for a speed > 0. In testing this seems to hold
true but as I couldn't test on all platforms I've avoided implementing
this. It also breaks for the corner case where you load the module
once the fans are idle.

Tested on P1G4, P1G3, X1C9 and T14 (no fans) and it works correctly.
For the platforms with dual fans where it was confirmed to work I have
removed the quirks. Potentially this could be done for all platforms
but I've left untested platforms in for now. On these platforms the
fans will be enabled and then detected - so no impact.

Signed-off-by: Mark Pearson <markpearson@lenovo.com>
Link: https://lore.kernel.org/r/20220222185137.4325-1-markpearson@lenovo.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2022-03-02 11:42:36 +01:00
..
chrome Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid 2021-11-24 09:44:13 -08:00
goldfish platform/goldfish: Convert pipe tasklet to threaded irq 2021-01-27 14:57:06 +01:00
mellanox platform/mellanox: mlxbf-pmc: Fix an IS_ERR() vs NULL bug in mlxbf_pmc_map_counters 2021-12-21 19:35:22 +01:00
mips MIPS: Loongson64: Add missing of_node_put() in ls2k_reset_init() 2022-01-05 09:53:45 +01:00
olpc Platform: OLPC: Constify static struct regulator_ops 2021-02-08 16:59:21 +01:00
surface surface: surface3_power: Fix battery readings on batteries without a serial number 2022-03-02 11:42:36 +01:00
x86 platform/x86: thinkpad_acpi: Add dual fan probe 2022-03-02 11:42:36 +01:00
Kconfig platform: Add Surface platform directory 2020-10-27 12:51:03 +01:00
Makefile platform: Add Surface platform directory 2020-10-27 12:51:03 +01:00