V4L/DVB (12940): SAA7164: IRQ / message timeout related change

In some cases we're seeing large timeouts on commands. I'm changing the
implementation so that the deferred worker checks the PCI bus for
any messages and signals the waiting caller accordingly. The previous
mechanism was too unreliable.
Signed-off-by: Steven Toth <stoth@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/saa7164/saa7164-cmd.c

@@ -78,6 +78,43 @@ u32 saa7164_cmd_timeout_get(struct saa7164_dev *dev, u8 seqno)
 	return ret;
 }
 
+/* Commands to the f/w get marshelled to/from this code then onto the PCI
+ * -bus/c running buffer. */
+int saa7164_irq_dequeue(struct saa7164_dev *dev)
+{
+	int ret = SAA_OK;
+	u32 timeout;
+	wait_queue_head_t *q = 0;
+	dprintk(DBGLVL_CMD, "%s()\n", __func__);
+
+	/* While any outstand message on the bus exists... */
+	do {
+
+		/* Peek the msg bus */
+		tmComResInfo_t tRsp = { 0, 0, 0, 0, 0, 0 };
+		ret = saa7164_bus_get(dev, &tRsp, NULL, 1);
+		if (ret != SAA_OK)
+			break;
+
+		q = &dev->cmds[tRsp.seqno].wait;
+		timeout = saa7164_cmd_timeout_get(dev, tRsp.seqno);
+		dprintk(DBGLVL_CMD, "%s() timeout = %d\n", __func__, timeout);
+		if (!timeout) {
+			dprintk(DBGLVL_CMD,
+				"%s() signalled seqno(%d) (for dequeue)\n",
+				__func__, tRsp.seqno);
+			dev->cmds[tRsp.seqno].signalled = 1;
+			wake_up(q);
+		} else {
+			printk(KERN_ERR
+				"%s() found timed out command on the bus\n",
+					__func__);
+		}
+	} while (0);
+
+	return ret;
+}
+
 /* Commands to the f/w get marshelled to/from this code then onto the PCI
  * -bus/c running buffer. */
 int saa7164_cmd_dequeue(struct saa7164_dev *dev)

drivers/media/video/saa7164/saa7164-core.c

@@ -69,7 +69,7 @@ static void saa7164_work_cmdhandler(struct work_struct *w)
 	struct saa7164_dev *dev = container_of(w, struct saa7164_dev, workcmd);
 
 	/* Wake up any complete commands */
-	saa7164_cmd_signal(dev, 0);
+	saa7164_irq_dequeue(dev);
 }
 
 static void saa7164_buffer_deliver(struct saa7164_buffer *buf)

drivers/media/video/saa7164/saa7164.h

@@ -328,6 +328,7 @@ int saa7164_cmd_send(struct saa7164_dev *dev,
 	u8 id, tmComResCmd_t command, u16 controlselector,
 	u16 size, void *buf);
 void saa7164_cmd_signal(struct saa7164_dev *dev, u8 seqno);
+int saa7164_irq_dequeue(struct saa7164_dev *dev);
 
 /* ----------------------------------------------------------- */
 /* saa7164-api.c                                               */