On 4/28/20 6:34 PM, Markus Armbruster wrote:
Both qdev_connect_gpio_out_named() and device_set_realized() put
objects without a parent into the "/machine/unattached/" orphanage.
qdev_connect_gpio_out_named() needs a lengthy comment to explain how
it works. It exploits that object_property_add_child() can fail only
when we got a parent already, and ignoring that error does what we
want. True. If it failed due to "duplicate property", we'd be in
trouble, but that would be a programming error.
device_set_realized() is cleaner: it checks whether we need a parent,
then calls object_property_add_child(), aborting on failure. No need
for a comment, and programming errors get caught.
I suppose it was not that obvious at the time of that comment :)
commit 615c4895703164134379b68214130dd502721174
Author: Andreas Färber <afaer...@suse.de>
Date: Wed Jun 18 00:57:08 2014 -0700
irq: Slim conversion of qemu_irq to QOM
As a prequel to any big Pin refactoring plans,
do an in-place conversion of qemu_irq to an Object,
so that we can reference it in link<> properties.
commit 02757df2ad2d5dfc96482e2cdfa046f439dafc3d
Author: Peter Crosthwaite <peter.crosthwa...@xilinx.com>
Date: Thu Sep 25 22:20:25 2014 -0700
qdev: gpio: Re-implement qdev_connect_gpio QOM style
Re-implement as a link setter. This should allow the
QOM framework to keep track of ref counts properly etc.
We need to add a default parent for the connecting
input in case it's coming from a non-qdev source.
We simply parent the IRQ to the machine in this case.
Change qdev_connect_gpio_out_named() to match.
Cc: Peter Crosthwaite <peter.crosthwa...@xilinx.com>
Signed-off-by: Markus Armbruster <arm...@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com>
---
hw/core/qdev.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)
diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index c3a6a11b19..888a1de931 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -541,15 +541,12 @@ void qdev_connect_gpio_out_named(DeviceState *dev, const
char *name, int n,
{
char *propname = g_strdup_printf("%s[%d]",
name ? name : "unnamed-gpio-out", n);
- if (pin) {
- /* We need a name for object_property_set_link to work. If the
- * object has a parent, object_property_add_child will come back
- * with an error without doing anything. If it has none, it will
- * never fail. So we can just call it with a NULL Error pointer.
- */
+ if (pin && !OBJECT(pin)->parent) {
+ /* We need a name for object_property_set_link to work */
object_property_add_child(container_get(qdev_get_machine(),
"/unattached"),
- "non-qdev-gpio[*]", OBJECT(pin), NULL);
+ "non-qdev-gpio[*]", OBJECT(pin),
+ &error_abort);
}
object_property_set_link(OBJECT(dev), OBJECT(pin), propname,
&error_abort);
g_free(propname);