[bug report] firmware: arm_scmi: Add atomic mode support to virtio transport

[Dan Carpenter]

Hello Cristian Marussi,

The patch 5a3b7185c47c: "firmware: arm_scmi: Add atomic mode support
to virtio transport" from Feb 17, 2022, leads to the following Smatch
static checker warning:

	drivers/firmware/arm_scmi/virtio.c:471 virtio_chan_setup()
	warn: 'vioch->deferred_tx_wq' from alloc_workqueue() not released on lines: 449,456,464.

drivers/firmware/arm_scmi/virtio.c
    419 static int virtio_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
    420                              bool tx)
    421 {
    422         struct scmi_vio_channel *vioch;
    423         int index = tx ? VIRTIO_SCMI_VQ_TX : VIRTIO_SCMI_VQ_RX;
    424         int i;
    425 
    426         if (!scmi_vdev)
    427                 return -EPROBE_DEFER;
    428 
    429         vioch = &((struct scmi_vio_channel *)scmi_vdev->priv)[index];
    430 
    431         /* Setup a deferred worker for polling. */
    432         if (tx && !vioch->deferred_tx_wq) {
    433                 vioch->deferred_tx_wq =
    434                         alloc_workqueue(dev_name(&scmi_vdev->dev),
    435                                         WQ_UNBOUND | WQ_FREEZABLE | WQ_SYSFS,
    436                                         0);

This workqueue is not freed on error paths.

    437                 if (!vioch->deferred_tx_wq)
    438                         return -ENOMEM;
    439 
    440                 INIT_WORK(&vioch->deferred_tx_work,
    441                           scmi_vio_deferred_tx_worker);
    442         }
    443 
    444         for (i = 0; i < vioch->max_msg; i++) {
    445                 struct scmi_vio_msg *msg;
    446 
    447                 msg = devm_kzalloc(cinfo->dev, sizeof(*msg), GFP_KERNEL);
    448                 if (!msg)
    449                         return -ENOMEM;

Here etc.

    450 
    451                 if (tx) {
    452                         msg->request = devm_kzalloc(cinfo->dev,
    453                                                     VIRTIO_SCMI_MAX_PDU_SIZE,
    454                                                     GFP_KERNEL);
    455                         if (!msg->request)
    456                                 return -ENOMEM;
    457                         spin_lock_init(&msg->poll_lock);
    458                         refcount_set(&msg->users, 1);
    459                 }
    460 
    461                 msg->input = devm_kzalloc(cinfo->dev, VIRTIO_SCMI_MAX_PDU_SIZE,
    462                                           GFP_KERNEL);
    463                 if (!msg->input)
    464                         return -ENOMEM;
    465 
    466                 scmi_finalize_message(vioch, msg);
    467         }
    468 
    469         scmi_vio_channel_ready(vioch, cinfo);
    470 
--> 471         return 0;
    472 }

regards,
dan carpenter