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authorZhu Guihua <zhugh.fnst@cn.fujitsu.com>2015-04-27 16:47:20 +0800
committerMichael S. Tsirkin <mst@redhat.com>2015-04-27 21:09:07 +0200
commit660e8ec70065c8b1fd68b2cb137de16d831959f4 (patch)
tree8ab1ff016d6d84d1ef5a05e3fc2696062e687ab8 /docs
parentaf5098973136029211848b4999ad5d38bc90180f (diff)
acpi: fix "Memory device control fields" register
0 bit in Memory device control fields must be cleared before writing to register. But now this field isn't cleared when other fields are written. To solve this bug, This patch fixes UpdateRule to WriteAsZeros in "Memory device control fields" register. Reviewed-by: Igor Mammedov <imammedo@redhat.com> Signed-off-by: Zhu Guihua <zhugh.fnst@cn.fujitsu.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'docs')
-rw-r--r--docs/specs/acpi_mem_hotplug.txt5
1 files changed, 4 insertions, 1 deletions
diff --git a/docs/specs/acpi_mem_hotplug.txt b/docs/specs/acpi_mem_hotplug.txt
index dcc4808918..68daa14764 100644
--- a/docs/specs/acpi_mem_hotplug.txt
+++ b/docs/specs/acpi_mem_hotplug.txt
@@ -31,7 +31,10 @@ Memory hot-plug interface (IO port 0xa00-0xa17, 1-4 byte access):
[0xc-0x13] reserved, writes into it are ignored
[0x14] Memory device control fields
bits:
- 0: reserved, OSPM must clear it before writing to register
+ 0: reserved, OSPM must clear it before writing to register.
+ Due to BUG in versions prior 2.4 that field isn't cleared
+ when other fields are written. Keep it reserved and don't
+ try to reuse it.
1: if set to 1 clears device insert event, set by OSPM
after it has emitted device check event for the
selected memory device