From: Alexey Kardashevskiy <aik@ozlabs.ru>

A "powernv" machine type defines an ISA bus but it does not add any DMA
controller to it so it is possible to hit assert(fdctrl->dma) by
adding "-machine powernv -device isa-fdc".

This replaces assert() with an error message.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
[thuth: Slightly adjusted error message and updated scripts/device-crash-test]
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 hw/block/fdc.c            | 5 ++++-
 scripts/device-crash-test | 1 -
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/hw/block/fdc.c b/hw/block/fdc.c
index 7b7dd41..cd29e27 100644
--- a/hw/block/fdc.c
+++ b/hw/block/fdc.c
@@ -2695,7 +2695,10 @@ static void isabus_fdc_realize(DeviceState *dev, Error **errp)
     fdctrl->dma_chann = isa->dma;
     if (fdctrl->dma_chann != -1) {
         fdctrl->dma = isa_get_dma(isa_bus_from_device(isadev), isa->dma);
-        assert(fdctrl->dma);
+        if (!fdctrl->dma) {
+            error_setg(errp, "ISA controller does not support DMA");
+            return;
+        }
     }
 
     qdev_set_legacy_instance_id(dev, isa->iobase, 2);
diff --git a/scripts/device-crash-test b/scripts/device-crash-test
index 7ff351d..99d20cb 100755
--- a/scripts/device-crash-test
+++ b/scripts/device-crash-test
@@ -217,7 +217,6 @@ ERROR_WHITELIST = [
     {'exitcode':-6, 'log':r"Object .* is not an instance of type generic-pc-machine", 'loglevel':logging.ERROR},
     {'exitcode':-6, 'log':r"Object .* is not an instance of type e500-ccsr", 'loglevel':logging.ERROR},
     {'exitcode':-6, 'log':r"vmstate_register_with_alias_id: Assertion `!se->compat \|\| se->instance_id == 0' failed", 'loglevel':logging.ERROR},
-    {'exitcode':-6, 'device':'isa-fdc', 'loglevel':logging.ERROR, 'expected':True},
     {'exitcode':-11, 'device':'gus', 'loglevel':logging.ERROR, 'expected':True},
     {'exitcode':-11, 'device':'isa-serial', 'loglevel':logging.ERROR, 'expected':True},
     {'exitcode':-11, 'device':'sb16', 'loglevel':logging.ERROR, 'expected':True},
-- 
1.8.3.1