[Qemu-devel] [PATCH v3 11/11] fdc: change auto fallback drive for ISA FDC to 288

[John Snow <jsnow@redhat.com>]

The 2.88 drive is more suitable as a default because
it can still read 1.44 images correctly, but the reverse
is not true.

Since there exist virtio-win drivers that are shipped on
2.88 floppy images, this patch will allow VMs booted without
a floppy disk inserted to later insert a 2.88MB floppy and
have that work.

This patch has been tested with msdos, freedos, fedora,
windows 8 and windows 10 without issue: if problems do
arise for certain guests being unable to cope with 2.88MB
drives as the default, they are in the minority and can use
type=144 as needed (or insert a proper boot medium and omit
type=144/288 or use type=auto) to obtain different drive types.

As icing, the default will remain auto/144 for any pre-2.6
machine types, hopefully minimizing the impact of this change
in legacy hw to basically zero.

Signed-off-by: John Snow <jsnow@redhat.com>
---
 hw/block/fdc.c      | 2 +-
 include/hw/compat.h | 6 +++++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/hw/block/fdc.c b/hw/block/fdc.c
index b9b9bf7..745b284 100644
--- a/hw/block/fdc.c
+++ b/hw/block/fdc.c
@@ -2524,7 +2524,7 @@ static Property isa_fdc_properties[] = {
                         FDRIVE_DEFAULT, qdev_prop_fdc_drive_type,
                         FloppyDriveType),
     DEFINE_PROP_DEFAULT("fallback", FDCtrlISABus, state.fallback,
-                        FLOPPY_DRIVE_TYPE_144, qdev_prop_fdc_drive_type,
+                        FLOPPY_DRIVE_TYPE_288, qdev_prop_fdc_drive_type,
                         FloppyDriveType),
     DEFINE_PROP_END_OF_LIST(),
 };
diff --git a/include/hw/compat.h b/include/hw/compat.h
index 24dd2c0..5a53f3c 100644
--- a/include/hw/compat.h
+++ b/include/hw/compat.h
@@ -2,7 +2,11 @@
 #define HW_COMPAT_H
 
 #define HW_COMPAT_2_5 \
-    /* empty */
+        {\
+            .driver   = "fdc",\
+            .property = "fallback",\
+            .value    = "144",\
+        },
 
 #define HW_COMPAT_2_4 \
     {\
-- 
2.4.3