Hi Heikki
On 26/05/2020 15:31, Heikki Krogerus wrote:
On Fri, May 22, 2020 at 11:57:36AM +0200, Mauro Carvalho Chehab wrote:
Em Thu, 21 May 2020 11:00:19 +0300
Andy Shevchenko <andy.shevchenko@xxxxxxxxx> escreveu:
+Cc: Heikki (swnode expert)
On Wed, May 20, 2020 at 2:19 PM Mauro Carvalho Chehab
<mchehab+huawei@xxxxxxxxxx> wrote:
Em Wed, 20 May 2020 11:26:08 +0300
Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> escreveu:
...
As I said, the problem is not probing the sensor via ACPI, but, instead,
to be able receive platform-specific data.
There is no problem with swnodes, except missing parts (*).
I have Skylake laptop with IPU3 and with half-baked ACPI tables, but
since we have drivers in place with fwnode support, we only need to
recreate fwnode graph in some board file to compensate the gap in
ACPI.
*) Missing part is graph support for swnodes. With that done it will
be feasible to achieve the rest.
I forgot if we have anything for this already done. Heikki?
Hmm... I guess I should try this approach. I never heard about swnodes
before. Do you have already some patch with the needed swnodes setup,
and the missing parts to recreate the fwnode graph?
Here you go. I tested it with this code:
static const struct software_node nodes[];
static const struct property_entry ep0_props[] = {
PROPERTY_ENTRY_REF("remote-endpoint", &nodes[5]),
{ }
};
static const struct property_entry ep1_props[] = {
PROPERTY_ENTRY_REF("remote-endpoint", &nodes[2]),
{ }
};
static const struct software_node nodes[] = {
{ "dev0" },
{ "port0", &nodes[0] },
{ "endpoint", &nodes[1], ep0_props },
{ "dev1" },
{ "port0", &nodes[3] },
{ "endpoint", &nodes[4], ep1_props },
{ }
};
void test(void)
{
const struct software_node *swnode;
struct fwnode_handle *fwnode;
software_node_register_nodes(nodes);
fwnode = fwnode_graph_get_remote_port_parent(software_node_fwnode(&nodes[5]));
swnode = to_software_node(fwnode);
printk("first parent: %s\n", swnode->name);
fwnode = fwnode_graph_get_remote_port_parent(software_node_fwnode(&nodes[2]));
swnode = to_software_node(fwnode);
printk("second parent: %s\n", swnode->name);
software_node_unregister_nodes(nodes);
}
thanks,
One of the problems we're having trying to build (using the changes you
attached here) a module to connect sensors to the cio2 infrastructure is
that we can't unload it cleanly. There seems to be a couple of reasons
for that; but one of them is that cio2_parse_firmware() in ipu3-cio2.c
ticks up the refcount for fwnode_handles of the ports for the CIO2
device by calling software_node_graph_get_next_endpoint() once per
_possible_ cio2 port; each time that happens it gets a reference to the
port's fwnode_handle but doesn't release it.
This isn't really a patch as such, since I don't think the changes you
attached are actually applied either upstream or in the media_tree git
(what are the plans in that regard, by the way? Will that patch be sent
upstream at some point?) so there's nowhere to apply it to, but I think
something like the below fixes it.
What do you think?
Regards,
Dan
---
diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
index 3667467196f0..62a1e3de8cb3 100644
--- a/drivers/base/swnode.c
+++ b/drivers/base/swnode.c
@@ -584,7 +584,9 @@ software_node_graph_get_next_endpoint(const struct
fwnode_handle *fwnode,
endpoint = software_node_get_next_child(port, old);
fwnode_handle_put(old);
if (endpoint)
- break;
+ break;
+ else
+ fwnode_handle_put(port);
}
fwnode_handle_put(port);
