V4L/DVB (8490): s2255drv Sensoray 2255 driver fixes

This patch fixes timer issues in driver disconnect.
It also removes the restriction of one user per channel at a time.

Thanks to Oliver Neukum and Mauro Chehab for finding these issues.
Locking of video stream partly based on saa7134 driver.
Signed-off-by: Dean Anderson <dean@sensoray.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

drivers/media/video/s2255drv.c

@@ -185,6 +185,7 @@ struct s2255_dmaqueue {
 #define S2255_FW_LOADED_DSPWAIT	1
 #define S2255_FW_SUCCESS	2
 #define S2255_FW_FAILED		3
+#define S2255_FW_DISCONNECTING  4
 
 struct s2255_fw {
 	int		      fw_loaded;
@@ -264,7 +265,6 @@ struct s2255_buffer {
 
 struct s2255_fh {
 	struct s2255_dev	*dev;
-	unsigned int		resources;
 	const struct s2255_fmt	*fmt;
 	unsigned int		width;
 	unsigned int		height;
@@ -274,14 +274,9 @@ struct s2255_fh {
 	/* mode below is the desired mode.
 	   mode in s2255_dev is the current mode that was last set */
 	struct s2255_mode	mode;
+	int			resources[MAX_CHANNELS];
 };
 
-/*
- * TODO: fixme S2255_MAX_USERS. Do not limit open driver handles.
- * Limit V4L to one stream at a time.
- */
-#define S2255_MAX_USERS         1
-
 #define CUR_USB_FWVER	774	/* current cypress EEPROM firmware version */
 #define S2255_MAJOR_VERSION	1
 #define S2255_MINOR_VERSION	13
@@ -477,10 +472,9 @@ static void s2255_timer(unsigned long user_data)
 	dprintk(100, "s2255 timer\n");
 	if (usb_submit_urb(data->fw_urb, GFP_ATOMIC) < 0) {
 		printk(KERN_ERR "s2255: can't submit urb\n");
-		if (data->fw) {
-			release_firmware(data->fw);
-			data->fw = NULL;
-		}
+		atomic_set(&data->fw_state, S2255_FW_FAILED);
+		/* wake up anything waiting for the firmware */
+		wake_up(&data->wait_fw);
 		return;
 	}
 }
@@ -510,13 +504,18 @@ static void s2255_fwchunk_complete(struct urb *urb)
 	struct usb_device *udev = urb->dev;
 	int len;
 	dprintk(100, "udev %p urb %p", udev, urb);
-	/* TODO: fixme.  reflect change in status */
 	if (urb->status) {
 		dev_err(&udev->dev, "URB failed with status %d", urb->status);
+		atomic_set(&data->fw_state, S2255_FW_FAILED);
+		/* wake up anything waiting for the firmware */
+		wake_up(&data->wait_fw);
 		return;
 	}
 	if (data->fw_urb == NULL) {
-		dev_err(&udev->dev, "early disconncect\n");
+		dev_err(&udev->dev, "s2255 disconnected\n");
+		atomic_set(&data->fw_state, S2255_FW_FAILED);
+		/* wake up anything waiting for the firmware */
+		wake_up(&data->wait_fw);
 		return;
 	}
 #define CHUNK_SIZE 512
@@ -790,7 +789,8 @@ static int res_get(struct s2255_dev *dev, struct s2255_fh *fh)
 	}
 	/* it's free, grab it */
 	dev->resources[fh->channel] = 1;
-	dprintk(1, "res: get\n");
+	fh->resources[fh->channel] = 1;
+	dprintk(1, "s2255: res: get\n");
 	mutex_unlock(&dev->lock);
 	return 1;
 }
@@ -800,9 +800,18 @@ static int res_locked(struct s2255_dev *dev, struct s2255_fh *fh)
 	return dev->resources[fh->channel];
 }
 
+static int res_check(struct s2255_fh *fh)
+{
+	return fh->resources[fh->channel];
+}
+
+
 static void res_free(struct s2255_dev *dev, struct s2255_fh *fh)
 {
+	mutex_lock(&dev->lock);
 	dev->resources[fh->channel] = 0;
+	fh->resources[fh->channel] = 0;
+	mutex_unlock(&dev->lock);
 	dprintk(1, "res: put\n");
 }
 
@@ -1233,7 +1242,7 @@ static int vidioc_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
 	}
 
 	if (!res_get(dev, fh)) {
-		dev_err(&dev->udev->dev, "res get busy\n");
+		dev_err(&dev->udev->dev, "s2255: stream busy\n");
 		return -EBUSY;
 	}
 
@@ -1289,8 +1298,10 @@ static int vidioc_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)
 	}
 	s2255_stop_acquire(dev, fh->channel);
 	res = videobuf_streamoff(&fh->vb_vidq);
+	if (res < 0)
+		return res;
 	res_free(dev, fh);
-	return res;
+	return 0;
 }
 
 static int vidioc_s_std(struct file *file, void *priv, v4l2_std_id *i)
@@ -1463,12 +1474,7 @@ static int s2255_open(struct inode *inode, struct file *file)
 	mutex_lock(&dev->open_lock);
 
 	dev->users[cur_channel]++;
-	if (dev->users[cur_channel] > S2255_MAX_USERS) {
-		dev->users[cur_channel]--;
-		mutex_unlock(&dev->open_lock);
-		printk(KERN_INFO "s2255drv: too many open handles!\n");
-		return -EBUSY;
-	}
+	dprintk(4, "s2255: open_handles %d\n", dev->users[cur_channel]);
 
 	if (atomic_read(&dev->fw_data->fw_state) == S2255_FW_FAILED) {
 		err("2255 firmware load failed. retrying.\n");
@@ -1479,7 +1485,8 @@ static int s2255_open(struct inode *inode, struct file *file)
 				   msecs_to_jiffies(S2255_LOAD_TIMEOUT));
 		if (atomic_read(&dev->fw_data->fw_state)
 		    != S2255_FW_SUCCESS) {
-			printk(KERN_INFO "2255 FW load failed after 2 tries\n");
+			printk(KERN_INFO "2255 FW load failed.\n");
+			dev->users[cur_channel]--;
 			mutex_unlock(&dev->open_lock);
 			return -EFAULT;
 		}
@@ -1495,6 +1502,7 @@ static int s2255_open(struct inode *inode, struct file *file)
 		    != S2255_FW_SUCCESS) {
 			printk(KERN_INFO "2255 firmware not loaded"
 			       "try again\n");
+			dev->users[cur_channel]--;
 			mutex_unlock(&dev->open_lock);
 			return -EBUSY;
 		}
@@ -1503,6 +1511,7 @@ static int s2255_open(struct inode *inode, struct file *file)
 	/* allocate + initialize per filehandle data */
 	fh = kzalloc(sizeof(*fh), GFP_KERNEL);
 	if (NULL == fh) {
+		dev->users[cur_channel]--;
 		mutex_unlock(&dev->open_lock);
 		return -ENOMEM;
 	}
@@ -1562,44 +1571,48 @@ static void s2255_destroy(struct kref *kref)
 		printk(KERN_ERR "s2255drv: kref problem\n");
 		return;
 	}
+
+	/*
+	 * Wake up any firmware load waiting (only done in .open,
+	 * which holds the open_lock mutex)
+	 */
+	atomic_set(&dev->fw_data->fw_state, S2255_FW_DISCONNECTING);
+	wake_up(&dev->fw_data->wait_fw);
+
 	/* prevent s2255_disconnect from racing s2255_open */
 	mutex_lock(&dev->open_lock);
 	s2255_exit_v4l(dev);
-	/* device unregistered so no longer possible to open. open_mutex
-	   can be unlocked */
+	/*
+	 * device unregistered so no longer possible to open. open_mutex
+	 *  can be unlocked and timers deleted afterwards.
+	 */
 	mutex_unlock(&dev->open_lock);
 
 	/* board shutdown stops the read pipe if it is running */
 	s2255_board_shutdown(dev);
 
 	/* make sure firmware still not trying to load */
+	del_timer(&dev->timer);  /* only started in .probe and .open */
+
 	if (dev->fw_data->fw_urb) {
 		dprintk(2, "kill fw_urb\n");
 		usb_kill_urb(dev->fw_data->fw_urb);
 		usb_free_urb(dev->fw_data->fw_urb);
 		dev->fw_data->fw_urb = NULL;
 	}
+
 	/*
-	 * TODO: fixme(above, below): potentially leaving timers alive.
-	 *                            do not ignore timeout below if
-	 *                            it occurs.
+	 * delete the dsp_wait timer, which sets the firmware
+	 * state on completion.  This is done before fw_data
+	 * is freed below.
 	 */
 
-	/* make sure we aren't waiting for the DSP */
-	if (atomic_read(&dev->fw_data->fw_state) == S2255_FW_LOADED_DSPWAIT) {
-		/* if we are, wait for the wakeup for fw_success or timeout */
-		wait_event_timeout(dev->fw_data->wait_fw,
-				   (atomic_read(&dev->fw_data->fw_state)
-				   == S2255_FW_SUCCESS),
-				   msecs_to_jiffies(S2255_LOAD_TIMEOUT));
-	}
+	del_timer(&dev->fw_data->dsp_wait); /* only started in .open */
 
-	if (dev->fw_data) {
-		if (dev->fw_data->fw)
-			release_firmware(dev->fw_data->fw);
-		kfree(dev->fw_data->pfw_data);
-		kfree(dev->fw_data);
-	}
+	if (dev->fw_data->fw)
+		release_firmware(dev->fw_data->fw);
+	kfree(dev->fw_data->pfw_data);
+	kfree(dev->fw_data);
 
 	usb_put_dev(dev->udev);
 	dprintk(1, "%s", __func__);
@@ -1616,17 +1629,23 @@ static int s2255_close(struct inode *inode, struct file *file)
 
 	mutex_lock(&dev->open_lock);
 
-	if (dev->b_acquire[fh->channel])
-		s2255_stop_acquire(dev, fh->channel);
-	res_free(dev, fh);
+	/* turn off stream */
+	if (res_check(fh)) {
+		if (dev->b_acquire[fh->channel])
+			s2255_stop_acquire(dev, fh->channel);
+		videobuf_streamoff(&fh->vb_vidq);
+		res_free(dev, fh);
+	}
+
 	videobuf_mmap_free(&fh->vb_vidq);
-	kfree(fh);
 	dev->users[fh->channel]--;
+
 	mutex_unlock(&dev->open_lock);
 
 	kref_put(&dev->kref, s2255_destroy);
 	dprintk(1, "s2255: close called (minor=%d, users=%d)\n",
 		minor, dev->users[fh->channel]);
+	kfree(fh);
 	return 0;
 }