V4L/DVB: s2255drv: cleanup of driver disconnect code

simplifies use of kref in driver

Signed-off-by: Dean Anderson <dean@sensoray.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 109 insertions, 157 deletions

diff --git a/drivers/media/video/s2255drv.c b/drivers/media/video/s2255drv.c
index 5ecd41b3bf3e..1d8c6b4364dd 100644
--- a/drivers/media/video/s2255drv.c
+++ b/drivers/media/video/s2255drv.c
@@ -226,7 +226,6 @@ struct s2255_fmt; /*forward declaration */
 
 struct s2255_dev {
         int                     frames;
-        int                     users[MAX_CHANNELS];
         struct mutex            lock;
         struct mutex            open_lock;
         int                     resources[MAX_CHANNELS];
@@ -367,7 +366,6 @@ static void s2255_fillbuff(struct s2255_dev *dev, struct s2255_buffer *buf,
 static int s2255_set_mode(struct s2255_dev *dev, unsigned long chn,
                           struct s2255_mode *mode);
 static int s2255_board_shutdown(struct s2255_dev *dev);
-static void s2255_exit_v4l(struct s2255_dev *dev);
 static void s2255_fwload_start(struct s2255_dev *dev, int reset);
 static void s2255_destroy(struct kref *kref);
 static long s2255_vendor_req(struct s2255_dev *dev, unsigned char req,
@@ -606,7 +604,6 @@ unlock:
         return 0;
 }
 
-
 static const struct s2255_fmt *format_by_fourcc(int fourcc)
 {
         unsigned int i;
@@ -620,9 +617,6 @@ static const struct s2255_fmt *format_by_fourcc(int fourcc)
         return NULL;
 }
 
-
-
-
 /* video buffer vmalloc implementation based partly on VIVI driver which is
  *          Copyright (c) 2006 by
  *                  Mauro Carvalho Chehab <mchehab--a.t--infradead.org>
@@ -849,7 +843,6 @@ static int vidioc_querymenu(struct file *file, void *priv,
         return v4l2_ctrl_query_menu(qmenu, NULL, NULL);
 }
 
-
 static int vidioc_querycap(struct file *file, void *priv,
                            struct v4l2_capability *cap)
 {
@@ -1759,31 +1752,26 @@ static int s2255_open(struct file *file)
         int i = 0;
         int cur_channel = -1;
         int state;
-
         dprintk(1, "s2255: open called (dev=%s)\n",
                 video_device_node_name(vdev));
-
         lock_kernel();
-
-        for (i = 0; i < MAX_CHANNELS; i++) {
+        for (i = 0; i < MAX_CHANNELS; i++)
                 if (dev->vdev[i] == vdev) {
                         cur_channel = i;
                         break;
                 }
-        }
-
-        if (atomic_read(&dev->fw_data->fw_state) == S2255_FW_DISCONNECTING) {
+        /*
+         * open lock necessary to prevent multiple instances
+         * of v4l-conf (or other programs) from simultaneously
+         * reloading firmware.
+         */
+        mutex_lock(&dev->open_lock);
+        state = atomic_read(&dev->fw_data->fw_state);
+        switch (state) {
+        case S2255_FW_DISCONNECTING:
+                mutex_unlock(&dev->open_lock);
                 unlock_kernel();
-                printk(KERN_INFO "disconnecting\n");
                 return -ENODEV;
-        }
-        kref_get(&dev->kref);
-        mutex_lock(&dev->open_lock);
-
-        dev->users[cur_channel]++;
-        dprintk(4, "s2255: open_handles %d\n", dev->users[cur_channel]);
-
-        switch (atomic_read(&dev->fw_data->fw_state)) {
         case S2255_FW_FAILED:
                 s2255_dev_err(&dev->udev->dev,
                         "firmware load failed. retrying.\n");
@@ -1794,6 +1782,8 @@ static int s2255_open(struct file *file)
                                     (atomic_read(&dev->fw_data->fw_state)
                                      == S2255_FW_DISCONNECTING)),
                                    msecs_to_jiffies(S2255_LOAD_TIMEOUT));
+                /* state may have changed, re-read */
+                state = atomic_read(&dev->fw_data->fw_state);
                 break;
         case S2255_FW_NOTLOADED:
         case S2255_FW_LOADED_DSPWAIT:
@@ -1806,52 +1796,44 @@ static int s2255_open(struct file *file)
                                     (atomic_read(&dev->fw_data->fw_state)
                                      == S2255_FW_DISCONNECTING)),
                         msecs_to_jiffies(S2255_LOAD_TIMEOUT));
+                /* state may have changed, re-read */
+                state = atomic_read(&dev->fw_data->fw_state);
                 break;
         case S2255_FW_SUCCESS:
         default:
                 break;
         }
-        state = atomic_read(&dev->fw_data->fw_state);
-        if (state != S2255_FW_SUCCESS) {
-                int rc;
-                switch (state) {
-                case S2255_FW_FAILED:
-                        printk(KERN_INFO "2255 FW load failed. %d\n", state);
-                        rc = -ENODEV;
-                        break;
-                case S2255_FW_DISCONNECTING:
-                        printk(KERN_INFO "%s: disconnecting\n", __func__);
-                        rc = -ENODEV;
-                        break;
-                case S2255_FW_LOADED_DSPWAIT:
-                case S2255_FW_NOTLOADED:
-                        printk(KERN_INFO "%s: firmware not loaded yet"
-                               "please try again later\n",
-                               __func__);
-                        rc = -EAGAIN;
-                        break;
-                default:
-                        printk(KERN_INFO "%s: unknown state\n", __func__);
-                        rc = -EFAULT;
-                        break;
-                }
-                dev->users[cur_channel]--;
-                mutex_unlock(&dev->open_lock);
-                kref_put(&dev->kref, s2255_destroy);
+        mutex_unlock(&dev->open_lock);
+        /* state may have changed in above switch statement */
+        switch (state) {
+        case S2255_FW_SUCCESS:
+                break;
+        case S2255_FW_FAILED:
+                printk(KERN_INFO "2255 firmware load failed.\n");
+                unlock_kernel();
+                return -ENODEV;
+        case S2255_FW_DISCONNECTING:
+                printk(KERN_INFO "%s: disconnecting\n", __func__);
+                unlock_kernel();
+                return -ENODEV;
+        case S2255_FW_LOADED_DSPWAIT:
+        case S2255_FW_NOTLOADED:
+                printk(KERN_INFO "%s: firmware not loaded yet"
+                       "please try again later\n",
+                       __func__);
+                unlock_kernel();
+                return -EAGAIN;
+        default:
+                printk(KERN_INFO "%s: unknown state\n", __func__);
                 unlock_kernel();
-                return rc;
+                return -EFAULT;
         }
-
         /* allocate + initialize per filehandle data */
         fh = kzalloc(sizeof(*fh), GFP_KERNEL);
         if (NULL == fh) {
-                dev->users[cur_channel]--;
-                mutex_unlock(&dev->open_lock);
-                kref_put(&dev->kref, s2255_destroy);
                 unlock_kernel();
                 return -ENOMEM;
         }
-
         file->private_data = fh;
         fh->dev = dev;
         fh->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
@@ -1866,9 +1848,8 @@ static int s2255_open(struct file *file)
                 s2255_set_mode(dev, cur_channel, &fh->mode);
                 dev->chn_configured[cur_channel] = 1;
         }
-        dprintk(1, "s2255drv: open dev=%s type=%s users=%d\n",
-                video_device_node_name(vdev), v4l2_type_names[type],
-                dev->users[cur_channel]);
+        dprintk(1, "s2255drv: open dev=%s type=%s\n",
+                video_device_node_name(vdev), v4l2_type_names[type]);
         dprintk(2, "s2255drv: open: fh=0x%08lx, dev=0x%08lx, vidq=0x%08lx\n",
                 (unsigned long)fh, (unsigned long)dev,
                 (unsigned long)&dev->vidq[cur_channel]);
@@ -1880,8 +1861,6 @@ static int s2255_open(struct file *file)
                                     fh->type,
                                     V4L2_FIELD_INTERLACED,
                                     sizeof(struct s2255_buffer), fh);
-
-        mutex_unlock(&dev->open_lock);
         unlock_kernel();
         return 0;
 }
@@ -1904,28 +1883,10 @@ static unsigned int s2255_poll(struct file *file,
 static void s2255_destroy(struct kref *kref)
 {
         struct s2255_dev *dev = to_s2255_dev(kref);
-        int i;
-        if (!dev) {
-                printk(KERN_ERR "s2255drv: kref problem\n");
-                return;
-        }
-        atomic_set(&dev->fw_data->fw_state, S2255_FW_DISCONNECTING);
-        wake_up(&dev->fw_data->wait_fw);
-        for (i = 0; i < MAX_CHANNELS; i++) {
-                dev->setmode_ready[i] = 1;
-                wake_up(&dev->wait_setmode[i]);
-                dev->vidstatus_ready[i] = 1;
-                wake_up(&dev->wait_vidstatus[i]);
-        }
-        mutex_lock(&dev->open_lock);
-        /* reset the DSP so firmware can be reload next time */
-        s2255_reset_dsppower(dev);
-        s2255_exit_v4l(dev);
         /* 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);
@@ -1936,24 +1897,22 @@ static void s2255_destroy(struct kref *kref)
                 release_firmware(dev->fw_data->fw);
         kfree(dev->fw_data->pfw_data);
         kfree(dev->fw_data);
+        /* reset the DSP so firmware can be reloaded next time */
+        s2255_reset_dsppower(dev);
+        mutex_destroy(&dev->open_lock);
+        mutex_destroy(&dev->lock);
         usb_put_dev(dev->udev);
         dprintk(1, "%s", __func__);
-
-        mutex_unlock(&dev->open_lock);
         kfree(dev);
 }
 
-static int s2255_close(struct file *file)
+static int s2255_release(struct file *file)
 {
         struct s2255_fh *fh = file->private_data;
         struct s2255_dev *dev = fh->dev;
         struct video_device *vdev = video_devdata(file);
-
         if (!dev)
                 return -ENODEV;
-
-        mutex_lock(&dev->open_lock);
-
         /* turn off stream */
         if (res_check(fh)) {
                 if (dev->b_acquire[fh->channel])
@@ -1961,15 +1920,8 @@ static int s2255_close(struct file *file)
                 videobuf_streamoff(&fh->vb_vidq);
                 res_free(dev, fh);
         }
-
         videobuf_mmap_free(&fh->vb_vidq);
-        dev->users[fh->channel]--;
-
-        mutex_unlock(&dev->open_lock);
-
-        kref_put(&dev->kref, s2255_destroy);
-        dprintk(1, "s2255: close called (dev=%s, users=%d)\n",
-                video_device_node_name(vdev), dev->users[fh->channel]);
+        dprintk(1, "%s (dev=%s)\n", __func__, video_device_node_name(vdev));
         kfree(fh);
         return 0;
 }
@@ -1995,7 +1947,7 @@ static int s2255_mmap_v4l(struct file *file, struct vm_area_struct *vma)
 static const struct v4l2_file_operations s2255_fops_v4l = {
         .owner = THIS_MODULE,
         .open = s2255_open,
-        .release = s2255_close,
+        .release = s2255_release,
         .poll = s2255_poll,
         .ioctl = video_ioctl2,  /* V4L2 ioctl handler */
         .mmap = s2255_mmap_v4l,
@@ -2031,11 +1983,19 @@ static const struct v4l2_ioctl_ops s2255_ioctl_ops = {
         .vidioc_enum_frameintervals = vidioc_enum_frameintervals,
 };
 
+static void s2255_video_device_release(struct video_device *vdev)
+{
+        struct s2255_dev *dev = video_get_drvdata(vdev);
+        video_device_release(vdev);
+        kref_put(&dev->kref, s2255_destroy);
+        return;
+}
+
 static struct video_device template = {
         .name = "s2255v",
         .fops = &s2255_fops_v4l,
         .ioctl_ops = &s2255_ioctl_ops,
-        .release = video_device_release,
+        .release = s2255_video_device_release,
         .tvnorms = S2255_NORMS,
         .current_norm = V4L2_STD_NTSC_M,
 };
@@ -2079,21 +2039,6 @@ static int s2255_probe_v4l(struct s2255_dev *dev)
         return ret;
 }
 
-static void s2255_exit_v4l(struct s2255_dev *dev)
-{
-
-        int i;
-        for (i = 0; i < MAX_CHANNELS; i++) {
-                if (video_is_registered(dev->vdev[i])) {
-                        video_unregister_device(dev->vdev[i]);
-                        printk(KERN_INFO "s2255 unregistered\n");
-                } else {
-                        video_device_release(dev->vdev[i]);
-                        printk(KERN_INFO "s2255 released\n");
-                }
-        }
-}
-
 /* this function moves the usb stream read pipe data
  * into the system buffers.
  * returns 0 on success, EAGAIN if more data to process( call this
@@ -2408,9 +2353,7 @@ static int s2255_board_init(struct s2255_dev *dev)
                         dprintk(1, "out of memory!\n");
                         return -ENOMEM;
                 }
-
         }
-
         /* query the firmware */
         fw_ver = s2255_get_fx2fw(dev);
 
@@ -2447,7 +2390,6 @@ static int s2255_board_init(struct s2255_dev *dev)
 static int s2255_board_shutdown(struct s2255_dev *dev)
 {
         u32 i;
-
         dprintk(1, "S2255: board shutdown: %p", dev);
 
         for (i = 0; i < MAX_CHANNELS; i++) {
@@ -2640,7 +2582,6 @@ static int s2255_stop_acquire(struct s2255_dev *dev, unsigned long chn)
 static void s2255_stop_readpipe(struct s2255_dev *dev)
 {
         int j;
-
         if (dev == NULL) {
                 s2255_dev_err(&dev->udev->dev, "invalid device\n");
                 return;
@@ -2654,7 +2595,6 @@ static void s2255_stop_readpipe(struct s2255_dev *dev)
                         pipe_info->state = 0;
                 }
         }
-
         for (j = 0; j < MAX_PIPE_BUFFERS; j++) {
                 struct s2255_pipeinfo *pipe_info = &dev->pipes[j];
                 if (pipe_info->stream_urb) {
@@ -2703,24 +2643,22 @@ static int s2255_probe(struct usb_interface *interface,
         dev = kzalloc(sizeof(struct s2255_dev), GFP_KERNEL);
         if (dev == NULL) {
                 s2255_dev_err(&interface->dev, "out of memory\n");
-                goto error;
+                return -ENOMEM;
         }
+        kref_init(&dev->kref);
         dev->pid = id->idProduct;
         dev->fw_data = kzalloc(sizeof(struct s2255_fw), GFP_KERNEL);
         if (!dev->fw_data)
-                goto error;
-
+                goto errorFWDATA1;
         mutex_init(&dev->lock);
         mutex_init(&dev->open_lock);
-
         /* grab usb_device and save it */
         dev->udev = usb_get_dev(interface_to_usbdev(interface));
         if (dev->udev == NULL) {
                 dev_err(&interface->dev, "null usb device\n");
                 retval = -ENODEV;
-                goto error;
+                goto errorUDEV;
         }
-        kref_init(&dev->kref);
         dprintk(1, "dev: %p, kref: %p udev %p interface %p\n", dev, &dev->kref,
                 dev->udev, interface);
         dev->interface = interface;
@@ -2737,14 +2675,11 @@ static int s2255_probe(struct usb_interface *interface,
 
         if (!dev->read_endpoint) {
                 dev_err(&interface->dev, "Could not find bulk-in endpoint\n");
-                goto error;
+                goto errorEP;
         }
-
         /* set intfdata */
         usb_set_intfdata(interface, dev);
-
         dprintk(100, "after intfdata %p\n", dev);
-
         init_timer(&dev->timer);
         dev->timer.function = s2255_timer;
         dev->timer.data = (unsigned long)dev->fw_data;
@@ -2756,21 +2691,21 @@ static int s2255_probe(struct usb_interface *interface,
         }
 
         dev->fw_data->fw_urb = usb_alloc_urb(0, GFP_KERNEL);
-
         if (!dev->fw_data->fw_urb) {
                 dev_err(&interface->dev, "out of memory!\n");
-                goto error;
+                goto errorFWURB;
         }
+
         dev->fw_data->pfw_data = kzalloc(CHUNK_SIZE, GFP_KERNEL);
         if (!dev->fw_data->pfw_data) {
                 dev_err(&interface->dev, "out of memory!\n");
-                goto error;
+                goto errorFWDATA2;
         }
         /* load the first chunk */
         if (request_firmware(&dev->fw_data->fw,
                              FIRMWARE_FILE_NAME, &dev->udev->dev)) {
                 printk(KERN_ERR "sensoray 2255 failed to get firmware\n");
-                goto error;
+                goto errorREQFW;
         }
         /* check the firmware is valid */
         fw_size = dev->fw_data->fw->size;
@@ -2779,7 +2714,7 @@ static int s2255_probe(struct usb_interface *interface,
         if (*pdata != S2255_FW_MARKER) {
                 printk(KERN_INFO "Firmware invalid.\n");
                 retval = -ENODEV;
-                goto error;
+                goto errorFWMARKER;
         } else {
                 /* make sure firmware is the latest */
                 __le32 *pRel;
@@ -2789,26 +2724,53 @@ static int s2255_probe(struct usb_interface *interface,
                 if (*pRel < S2255_CUR_DSP_FWVER)
                         printk(KERN_INFO "s2255: f2255usb.bin out of date.\n");
                 if (dev->pid == 0x2257 && *pRel < S2255_MIN_DSP_COLORFILTER)
-                        printk(KERN_WARNING "s2255: 2257 requires firmware 8 or above.\n");
+                        printk(KERN_WARNING "s2255: 2257 requires firmware %d"
+                               "or above.\n", S2255_MIN_DSP_COLORFILTER);
         }
-        /* loads v4l specific */
-        s2255_probe_v4l(dev);
         usb_reset_device(dev->udev);
         /* load 2255 board specific */
         retval = s2255_board_init(dev);
         if (retval)
-                goto error;
-
+                goto errorBOARDINIT;
         dprintk(4, "before probe done %p\n", dev);
         spin_lock_init(&dev->slock);
-
         s2255_fwload_start(dev, 0);
+        /* kref for each vdev. Released on video_device_release callback */
+        for (i = 0; i < MAX_CHANNELS; i++)
+                kref_get(&dev->kref);
+        /* loads v4l specific */
+        retval = s2255_probe_v4l(dev);
+        if (retval)
+                goto errorV4L;
         dev_info(&interface->dev, "Sensoray 2255 detected\n");
         return 0;
-error:
+errorV4L:
+        for (i = 0; i < MAX_CHANNELS; i++)
+                if (dev->vdev[i] && video_is_registered(dev->vdev[i]))
+                        video_unregister_device(dev->vdev[i]);
+errorBOARDINIT:
+        s2255_board_shutdown(dev);
+errorFWMARKER:
+        release_firmware(dev->fw_data->fw);
+errorREQFW:
+        kfree(dev->fw_data->pfw_data);
+errorFWDATA2:
+        usb_free_urb(dev->fw_data->fw_urb);
+errorFWURB:
+        del_timer(&dev->timer);
+errorEP:
+        usb_put_dev(dev->udev);
+errorUDEV:
+        kfree(dev->fw_data);
+        mutex_destroy(&dev->open_lock);
+        mutex_destroy(&dev->lock);
+errorFWDATA1:
+        kfree(dev);
+        printk(KERN_WARNING "Sensoray 2255 driver load failed: 0x%x\n", retval);
         return retval;
 }
 
+
 /* disconnect routine. when board is removed physically or with rmmod */
 static void s2255_disconnect(struct usb_interface *interface)
 {
@@ -2816,11 +2778,11 @@ static void s2255_disconnect(struct usb_interface *interface)
         int i;
         dprintk(1, "s2255: disconnect interface %p\n", interface);
         dev = usb_get_intfdata(interface);
-
-        /*
-         * wake up any of the timers to allow open_lock to be
-         * acquired sooner
-         */
+        /* unregister each video device. */
+        for (i = 0; i < MAX_CHANNELS; i++)
+                if (video_is_registered(dev->vdev[i]))
+                        video_unregister_device(dev->vdev[i]);
+        /* wake up any of our timers */
         atomic_set(&dev->fw_data->fw_state, S2255_FW_DISCONNECTING);
         wake_up(&dev->fw_data->wait_fw);
         for (i = 0; i < MAX_CHANNELS; i++) {
@@ -2829,16 +2791,9 @@ static void s2255_disconnect(struct usb_interface *interface)
                 dev->vidstatus_ready[i] = 1;
                 wake_up(&dev->wait_vidstatus[i]);
         }
-
-        mutex_lock(&dev->open_lock);
         usb_set_intfdata(interface, NULL);
-        mutex_unlock(&dev->open_lock);
-
-        if (dev) {
-                kref_put(&dev->kref, s2255_destroy);
-                dprintk(1, "s2255drv: disconnect\n");
-                dev_info(&interface->dev, "s2255usb now disconnected\n");
-        }
+        kref_put(&dev->kref, s2255_destroy);
+        dev_info(&interface->dev, "%s\n", __func__);
 }
 
 static struct usb_driver s2255_driver = {
@@ -2851,15 +2806,12 @@ static struct usb_driver s2255_driver = {
 static int __init usb_s2255_init(void)
 {
         int result;
-
         /* register this driver with the USB subsystem */
         result = usb_register(&s2255_driver);
-
         if (result)
                 pr_err(KBUILD_MODNAME
-                        ": usb_register failed. Error number %d\n", result);
-
-        dprintk(2, "s2255_init: done\n");
+                       ": usb_register failed. Error number %d\n", result);
+        dprintk(2, "%s\n", __func__);
         return result;
 }