Commit 54d85d69 authored by Brian Masney's avatar Brian Masney Committed by Jonathan Corbet
Browse files

docs: clk: add documentation to log which clocks have been disabled 



The existing clk documentation has a section that talks about the
clk_ignore_unused kernel parameter. Add additional documentation that
describes how to log which clocks the kernel disables on bootup. This
will log messages like the following to the console on bootup:

    [    1.268115] clk: Disabling unused clocks
    [    1.272167] clk_disable: gcc_usb_clkref_en
    [    1.276389] clk_disable: gcc_usb30_sec_sleep_clk
    [    1.281131] clk_disable: gcc_usb30_prim_sleep_clk
    ...

Signed-off-by: default avatarBrian Masney <bmasney@redhat.com>
Link: https://lore.kernel.org/r/20230411192153.289688-1-bmasney@redhat.com


[jc: turned parameters into a literal block]
Signed-off-by: default avatarJonathan Corbet <corbet@lwn.net>
parent c9b951c3

Documentation/driver-api/clk.rst

+5 −0
Original line number Diff line number Diff line
@@ -258,6 +258,11 @@ clocks properly but rely on them being on from the bootloader, bypassing 
the disabling means that the driver will remain functional while the issues

are sorted out.



You can see which clocks have been disabled by booting your kernel with these

parameters::



 tp_printk trace_event=clk:clk_disable



To bypass this disabling, include "clk_ignore_unused" in the bootargs to the

kernel.