diff options
| author | Michael S. Tsirkin <mst@redhat.com> | 2015-03-05 10:45:49 +1030 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2015-03-28 09:36:55 -0400 |
| commit | ee7fb5b37197d87a1bcf4e47b3b7f03ce6d02862 (patch) | |
| tree | 571050cfaeb52d89ee5e39c1d19edc77615e46c8 /drivers | |
| parent | 0b39fb19628e0f55676ce81e1411c45b7aebf43f (diff) | |
virtio_console: avoid config access from irq
[ Upstream commit eeb8a7e8bb123e84daeef84f5a2eab99ad2839a2 ]
when multiport is off, virtio console invokes config access from irq
context, config access is blocking on s390.
Fix this up by scheduling work from config irq - similar to what we do
for multiport configs.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/char/virtio_console.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 9724a6995903..6e09c1dac2b7 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -142,6 +142,7 @@ struct ports_device { * notification */ struct work_struct control_work; + struct work_struct config_work; struct list_head ports; @@ -1832,10 +1833,21 @@ static void config_intr(struct virtio_device *vdev) portdev = vdev->priv; + if (!use_multiport(portdev)) + schedule_work(&portdev->config_work); +} + +static void config_work_handler(struct work_struct *work) +{ + struct ports_device *portdev; + + portdev = container_of(work, struct ports_device, control_work); if (!use_multiport(portdev)) { + struct virtio_device *vdev; struct port *port; u16 rows, cols; + vdev = portdev->vdev; virtio_cread(vdev, struct virtio_console_config, cols, &cols); virtio_cread(vdev, struct virtio_console_config, rows, &rows); @@ -2026,6 +2038,7 @@ static int virtcons_probe(struct virtio_device *vdev) virtio_device_ready(portdev->vdev); + INIT_WORK(&portdev->config_work, &config_work_handler); INIT_WORK(&portdev->control_work, &control_work_handler); if (multiport) { @@ -2100,6 +2113,8 @@ static void virtcons_remove(struct virtio_device *vdev) /* Finish up work that's lined up */ if (use_multiport(portdev)) cancel_work_sync(&portdev->control_work); + else + cancel_work_sync(&portdev->config_work); list_for_each_entry_safe(port, port2, &portdev->ports, list) unplug_port(port); @@ -2151,6 +2166,7 @@ static int virtcons_freeze(struct virtio_device *vdev) virtqueue_disable_cb(portdev->c_ivq); cancel_work_sync(&portdev->control_work); + cancel_work_sync(&portdev->config_work); /* * Once more: if control_work_handler() was running, it would * enable the cb as the last step. |