docs: document stop-a in sysctl/kernel.rst

This describes the SPARC-specific stop-a sysctl entry, which was
previously listed in kernel.rst but not documented.

Base on the implementation in arch/sparc/kernel/setup_{32,64}.c and
kernel/panic.c.

Signed-off-by: Stephen Kitt <steve@sk2.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
index 0ae52156db75f2fd53f6be495d64f4e56dbdff68..3cbbe4502e18c824a483a6f728964f41d00f6f2a 100644 (file)
--- a/Documentation/admin-guide/sysctl/kernel.rst
+++ b/Documentation/admin-guide/sysctl/kernel.rst
@@ -1069,6 +1069,16 @@ compilation sees a 1% slowdown, other systems and workloads may vary.
 stop-a (SPARC only)
 ===================
 
+Controls Stop-A:
+
+= ====================================
+0 Stop-A has no effect.
+1 Stop-A breaks to the PROM (default).
+= ====================================
+
+Stop-A is always enabled on a panic, so that the user can return to
+the boot PROM.
+
 
 sysrq
 =====