NFC: Convert pn533 from tasklet to workqueues

There is no need for soft IRQ contexts, and workqueues are more flexible.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 48 insertions, 38 deletions

diff --git a/drivers/nfc/pn533.c b/drivers/nfc/pn533.c
index cb6204f78300..f2ee06f059f9 100644
--- a/drivers/nfc/pn533.c
+++ b/drivers/nfc/pn533.c
@@ -266,9 +266,10 @@ struct pn533 {
         int in_maxlen;
         struct pn533_frame *in_frame;
 
-        struct tasklet_struct tasklet;
-        struct pn533_frame *tklt_in_frame;
-        int tklt_in_error;
+        struct workqueue_struct *wq;
+        struct work_struct cmd_work;
+        struct pn533_frame *wq_in_frame;
+        int wq_in_error;
 
         pn533_cmd_complete_t cmd_complete;
         void *cmd_complete_arg;
@@ -383,15 +384,21 @@ static bool pn533_rx_frame_is_cmd_response(struct pn533_frame *frame, u8 cmd)
         return (PN533_FRAME_CMD(frame) == PN533_CMD_RESPONSE(cmd));
 }
 
-static void pn533_tasklet_cmd_complete(unsigned long arg)
+
+static void pn533_wq_cmd_complete(struct work_struct *work)
 {
-        struct pn533 *dev = (struct pn533 *) arg;
-        struct pn533_frame *in_frame = dev->tklt_in_frame;
+        struct pn533 *dev = container_of(work, struct pn533, cmd_work);
+        struct pn533_frame *in_frame;
         int rc;
 
-        if (dev->tklt_in_error)
+        if (dev == NULL)
+                return;
+
+        in_frame = dev->wq_in_frame;
+
+        if (dev->wq_in_error)
                 rc = dev->cmd_complete(dev, dev->cmd_complete_arg, NULL,
-                                                        dev->tklt_in_error);
+                                                        dev->wq_in_error);
         else
                 rc = dev->cmd_complete(dev, dev->cmd_complete_arg,
                                         PN533_FRAME_CMD_PARAMS_PTR(in_frame),
@@ -406,7 +413,7 @@ static void pn533_recv_response(struct urb *urb)
         struct pn533 *dev = urb->context;
         struct pn533_frame *in_frame;
 
-        dev->tklt_in_frame = NULL;
+        dev->wq_in_frame = NULL;
 
         switch (urb->status) {
         case 0:
@@ -417,36 +424,36 @@ static void pn533_recv_response(struct urb *urb)
         case -ESHUTDOWN:
                 nfc_dev_dbg(&dev->interface->dev, "Urb shutting down with"
                                                 " status: %d", urb->status);
-                dev->tklt_in_error = urb->status;
-                goto sched_tasklet;
+                dev->wq_in_error = urb->status;
+                goto sched_wq;
         default:
                 nfc_dev_err(&dev->interface->dev, "Nonzero urb status received:"
                                                         " %d", urb->status);
-                dev->tklt_in_error = urb->status;
-                goto sched_tasklet;
+                dev->wq_in_error = urb->status;
+                goto sched_wq;
         }
 
         in_frame = dev->in_urb->transfer_buffer;
 
         if (!pn533_rx_frame_is_valid(in_frame)) {
                 nfc_dev_err(&dev->interface->dev, "Received an invalid frame");
-                dev->tklt_in_error = -EIO;
-                goto sched_tasklet;
+                dev->wq_in_error = -EIO;
+                goto sched_wq;
         }
 
         if (!pn533_rx_frame_is_cmd_response(in_frame, dev->cmd)) {
                 nfc_dev_err(&dev->interface->dev, "The received frame is not "
                                                 "response to the last command");
-                dev->tklt_in_error = -EIO;
-                goto sched_tasklet;
+                dev->wq_in_error = -EIO;
+                goto sched_wq;
         }
 
         nfc_dev_dbg(&dev->interface->dev, "Received a valid frame");
-        dev->tklt_in_error = 0;
-        dev->tklt_in_frame = in_frame;
+        dev->wq_in_error = 0;
+        dev->wq_in_frame = in_frame;
 
-sched_tasklet:
-        tasklet_schedule(&dev->tasklet);
+sched_wq:
+        queue_work(dev->wq, &dev->cmd_work);
 }
 
 static int pn533_submit_urb_for_response(struct pn533 *dev, gfp_t flags)
@@ -471,21 +478,21 @@ static void pn533_recv_ack(struct urb *urb)
         case -ESHUTDOWN:
                 nfc_dev_dbg(&dev->interface->dev, "Urb shutting down with"
                                                 " status: %d", urb->status);
-                dev->tklt_in_error = urb->status;
-                goto sched_tasklet;
+                dev->wq_in_error = urb->status;
+                goto sched_wq;
         default:
                 nfc_dev_err(&dev->interface->dev, "Nonzero urb status received:"
                                                         " %d", urb->status);
-                dev->tklt_in_error = urb->status;
-                goto sched_tasklet;
+                dev->wq_in_error = urb->status;
+                goto sched_wq;
         }
 
         in_frame = dev->in_urb->transfer_buffer;
 
         if (!pn533_rx_frame_is_ack(in_frame)) {
                 nfc_dev_err(&dev->interface->dev, "Received an invalid ack");
-                dev->tklt_in_error = -EIO;
-                goto sched_tasklet;
+                dev->wq_in_error = -EIO;
+                goto sched_wq;
         }
 
         nfc_dev_dbg(&dev->interface->dev, "Received a valid ack");
@@ -494,15 +501,15 @@ static void pn533_recv_ack(struct urb *urb)
         if (rc) {
                 nfc_dev_err(&dev->interface->dev, "usb_submit_urb failed with"
                                                         " result %d", rc);
-                dev->tklt_in_error = rc;
-                goto sched_tasklet;
+                dev->wq_in_error = rc;
+                goto sched_wq;
         }
 
         return;
 
-sched_tasklet:
-        dev->tklt_in_frame = NULL;
-        tasklet_schedule(&dev->tasklet);
+sched_wq:
+        dev->wq_in_frame = NULL;
+        queue_work(dev->wq, &dev->cmd_work);
 }
 
 static int pn533_submit_urb_for_ack(struct pn533 *dev, gfp_t flags)
@@ -1668,7 +1675,10 @@ static int pn533_probe(struct usb_interface *interface,
                         NULL, 0,
                         pn533_send_complete, dev);
 
-        tasklet_init(&dev->tasklet, pn533_tasklet_cmd_complete, (ulong)dev);
+        INIT_WORK(&dev->cmd_work, pn533_wq_cmd_complete);
+        dev->wq = create_singlethread_workqueue("pn533");
+        if (dev->wq == NULL)
+                goto error;
 
         usb_set_intfdata(interface, dev);
 
@@ -1678,7 +1688,7 @@ static int pn533_probe(struct usb_interface *interface,
         rc = pn533_send_cmd_frame_sync(dev, dev->out_frame, dev->in_frame,
                                                                 dev->in_maxlen);
         if (rc)
-                goto kill_tasklet;
+                goto destroy_wq;
 
         fw_ver = (struct pn533_fw_version *)
                                 PN533_FRAME_CMD_PARAMS_PTR(dev->in_frame);
@@ -1694,7 +1704,7 @@ static int pn533_probe(struct usb_interface *interface,
                                            PN533_CMD_DATAEXCH_HEAD_LEN,
                                            PN533_FRAME_TAIL_SIZE);
         if (!dev->nfc_dev)
-                goto kill_tasklet;
+                goto destroy_wq;
 
         nfc_set_parent_dev(dev->nfc_dev, &interface->dev);
         nfc_set_drvdata(dev->nfc_dev, dev);
@@ -1720,8 +1730,8 @@ static int pn533_probe(struct usb_interface *interface,
 
 free_nfc_dev:
         nfc_free_device(dev->nfc_dev);
-kill_tasklet:
-        tasklet_kill(&dev->tasklet);
+destroy_wq:
+        destroy_workqueue(dev->wq);
 error:
         kfree(dev->in_frame);
         usb_free_urb(dev->in_urb);
@@ -1744,7 +1754,7 @@ static void pn533_disconnect(struct usb_interface *interface)
         usb_kill_urb(dev->in_urb);
         usb_kill_urb(dev->out_urb);
 
-        tasklet_kill(&dev->tasklet);
+        destroy_workqueue(dev->wq);
 
         kfree(dev->in_frame);
         usb_free_urb(dev->in_urb);