qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Qemu-devel] [PATCH v7 6/8] acpi: fix "Memory device control fields" reg


From: Zhu Guihua
Subject: [Qemu-devel] [PATCH v7 6/8] acpi: fix "Memory device control fields" register
Date: Mon, 27 Apr 2015 16:47:20 +0800

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 <address@hidden>
Signed-off-by: Zhu Guihua <address@hidden>
---
 docs/specs/acpi_mem_hotplug.txt | 5 ++++-
 hw/i386/acpi-build.c            | 2 +-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/docs/specs/acpi_mem_hotplug.txt b/docs/specs/acpi_mem_hotplug.txt
index dcc4808..68daa14 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
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index dc1b8e8..eb66fef 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -924,7 +924,7 @@ build_ssdt(GArray *table_data, GArray *linker,
         aml_append(scope, field);
 
         field = aml_field(stringify(MEMORY_HOTPLUG_IO_REGION), aml_byte_acc,
-                          aml_preserve);
+                          aml_write_as_zeros);
         aml_append(field, aml_reserved_field(160 /* bits, Offset(20) */));
         aml_append(field, /* 1 if enabled, read only */
             aml_named_field(stringify(MEMORY_SLOT_ENABLED), 1));
-- 
1.9.3




reply via email to

[Prev in Thread] Current Thread [Next in Thread]