From bbaca7115167088e8177ab8cc7aafdcb8666dea9 Mon Sep 17 00:00:00 2001
From: Viresh Kumar <viresh.kumar@linaro.org>
Date: Wed, 23 Sep 2015 16:48:08 -0700
Subject: [PATCH] greybus: svc: Allow consecutive hotplug events for the same
module
There are two cases where the AP may receive hotplug event for an
existing interface, without first getting a hot-unplug request for it.
- bootrom loading the firmware image and booting into that, which
only generates a hotplug event. i.e. no hot-unplug event, as the
module never went away.
- Or the firmware on the module crashed and sent hotplug request again
to the SVC, which got propagated to AP.
Handle such cases by first removing the interface, with a clear print
message shown to the user. And then following the normal hotplug
sequence to add the interface.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
---
drivers/staging/greybus/svc.c | 52 +++++++++++++++++++++++++++--------
1 file changed, 41 insertions(+), 11 deletions(-)
diff --git a/drivers/staging/greybus/svc.c b/drivers/staging/greybus/svc.c
index 056351fe9449..0e029ce40379 100644
--- a/drivers/staging/greybus/svc.c
+++ b/drivers/staging/greybus/svc.c
@@ -329,6 +329,25 @@ static int gb_svc_hello(struct gb_operation *op)
return 0;
}
+static void svc_intf_remove(struct gb_connection *connection,
+ struct gb_interface *intf)
+{
+ struct greybus_host_device *hd = connection->hd;
+ struct gb_svc *svc = connection->private;
+ u8 intf_id = intf->interface_id;
+ u8 device_id;
+
+ device_id = intf->device_id;
+ gb_interface_remove(hd, intf_id);
+
+ /*
+ * Destroy the two-way route between the AP and the interface.
+ */
+ gb_svc_route_destroy(svc, hd->endo->ap_intf_id, intf_id);
+
+ ida_simple_remove(&svc->device_id_map, device_id);
+}
+
/*
* 'struct svc_hotplug' should be freed by svc_process_hotplug() before it
* returns, irrespective of success or Failure in bringing up the module.
@@ -351,6 +370,27 @@ static void svc_process_hotplug(struct work_struct *work)
*/
intf_id = hotplug->intf_id;
+ intf = gb_interface_find(hd, intf_id);
+ if (intf) {
+ /*
+ * We have received a hotplug request for an interface that
+ * already exists.
+ *
+ * This can happen in cases like:
+ * - bootrom loading the firmware image and booting into that,
+ * which only generates a hotplug event. i.e. no hot-unplug
+ * event.
+ * - Or the firmware on the module crashed and sent hotplug
+ * request again to the SVC, which got propagated to AP.
+ *
+ * Remove the interface and add it again, and let user know
+ * about this with a print message.
+ */
+ dev_info(dev, "Removed interface (%hhu) to add it again\n",
+ intf_id);
+ svc_intf_remove(connection, intf);
+ }
+
intf = gb_interface_create(hd, intf_id);
if (!intf) {
dev_err(dev, "%s: Failed to create interface with id %hhu\n",
@@ -463,8 +503,6 @@ static int gb_svc_intf_hot_unplug_recv(struct gb_operation *op)
struct gb_svc_intf_hot_unplug_request *hot_unplug = request->payload;
struct greybus_host_device *hd = op->connection->hd;
struct device *dev = &op->connection->dev;
- struct gb_svc *svc = op->connection->private;
- u8 device_id;
struct gb_interface *intf;
u8 intf_id;
@@ -483,15 +521,7 @@ static int gb_svc_intf_hot_unplug_recv(struct gb_operation *op)
return -EINVAL;
}
- device_id = intf->device_id;
- gb_interface_remove(hd, intf_id);
-
- /*
- * Destroy the two-way route between the AP and the interface.
- */
- gb_svc_route_destroy(svc, hd->endo->ap_intf_id, intf_id);
-
- ida_simple_remove(&svc->device_id_map, device_id);
+ svc_intf_remove(op->connection, intf);
return 0;
}
--
2.30.2