doc/kernel-parameters.txt: clarify clk_ignore_unused

Refine the definition around clk_ignore_unused, which caused some
confusion recently on the linux-fbdev and linux-arm-kernel mailing
lists[0].

[0] http://lkml.kernel.org/r/<20140929135358.GC30998@ulmo>

Signed-off-by: Mike Turquette <mturquette@linaro.org>

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 10d51c2..0ce01fb 100644 (file)
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -605,11 +605,15 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        See Documentation/s390/CommonIO for details.
        clk_ignore_unused
                        [CLK]
-                       Keep all clocks already enabled by bootloader on,
-                       even if no driver has claimed them. This is useful
-                       for debug and development, but should not be
-                       needed on a platform with proper driver support.
-                       For more information, see Documentation/clk.txt.
+                       Prevents the clock framework from automatically gating
+                       clocks that have not been explicitly enabled by a Linux
+                       device driver but are enabled in hardware at reset or
+                       by the bootloader/firmware. Note that this does not
+                       force such clocks to be always-on nor does it reserve
+                       those clocks in any way. This parameter is useful for
+                       debug and development, but should not be needed on a
+                       platform with proper driver support.  For more
+                       information, see Documentation/clk.txt.
 
        clock=          [BUGS=X86-32, HW] gettimeofday clocksource override.
                        [Deprecated]