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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>
This commit is contained in:
Viresh Kumar 2015-09-23 16:48:08 -07:00 committed by Greg Kroah-Hartman
parent c06307c3b4
commit bbaca71151
1 changed files with 41 additions and 11 deletions
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52
drivers/staging/greybus/svc.c
View File

@ -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;
}