From 1c532e00a0c649ac6f0703e8c2e095c9c1d30625 Mon Sep 17 00:00:00 2001 From: Alex Thorlton Date: Thu, 31 Mar 2016 14:18:29 -0500 Subject: x86/platform/uv: Disable UV BAU by default For several years, the common practice has been to boot UVs with the "nobau" parameter on the command line, to disable the BAU. We've decided that it makes more sense to just disable the BAU by default in the kernel, and provide the option to turn it on, if desired. For now, having the on/off switch doesn't buy us any more than just reversing the logic would, but we're working towards having the BAU enabled by default on UV4. When those changes are in place, having the on/off switch will make more sense than an enable flag, since the default behavior will be different depending on the system version. I've also added a bit of documentation for the new parameter to Documentation/kernel-parameters.txt. Signed-off-by: Alex Thorlton Reviewed-by: Hedi Berriche Cc: Jonathan Corbet Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1459451909-121845-1-git-send-email-athorlton@sgi.com Signed-off-by: Ingo Molnar --- Documentation/kernel-parameters.txt | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'Documentation/kernel-parameters.txt') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index ecc74fa4bfde..893a70907f15 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -131,6 +131,7 @@ parameter is applicable: More X86-64 boot options can be found in Documentation/x86/x86_64/boot-options.txt . X86 Either 32-bit or 64-bit x86 (same as X86-32+X86-64) + X86_UV SGI UV support is enabled. XEN Xen support is enabled In addition, the following text indicates that the option: @@ -542,6 +543,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted. Format: (must be >=0) Default: 64 + bau= [X86_UV] Enable the BAU on SGI UV. The default + behavior is to disable the BAU (i.e. bau=0). + Format: { "0" | "1" } + 0 - Disable the BAU. + 1 - Enable the BAU. + unset - Disable the BAU. + baycom_epp= [HW,AX25] Format: , -- cgit v1.2.3