staging: most: v4l2-aim: fix interrupt unsafe spinlocks

The functions get_aim_dev() and aim_rx_data() are using interrupt unsafe
spinlocks even though they may be called from an interrupt context.

This patch fixes the described problem.

Signed-off-by: Andrey Shvetsov <andrey.shvetsov@k2l.de>
Signed-off-by: Christian Gromm <christian.gromm@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/most/aim-v4l2/video.c b/drivers/staging/most/aim-v4l2/video.c
index 13abf7c275a4e9809c5e2eb02faf1a135493a5af..1fea839e3c58759c2974da9d09554fe0a1a499b5 100644 (file)
--- a/drivers/staging/most/aim-v4l2/video.c
+++ b/drivers/staging/most/aim-v4l2/video.c
@@ -139,15 +139,15 @@ static int aim_vdev_close(struct file *filp)
         * This must be implemented in core.
         */
 
-       spin_lock(&mdev->list_lock);
+       spin_lock_irq(&mdev->list_lock);
        mdev->mute = true;
        list_for_each_entry_safe(mbo, tmp, &mdev->pending_mbos, list) {
                list_del(&mbo->list);
-               spin_unlock(&mdev->list_lock);
+               spin_unlock_irq(&mdev->list_lock);
                most_put_mbo(mbo);
-               spin_lock(&mdev->list_lock);
+               spin_lock_irq(&mdev->list_lock);
        }
-       spin_unlock(&mdev->list_lock);
+       spin_unlock_irq(&mdev->list_lock);
        most_stop_channel(mdev->iface, mdev->ch_idx, &aim_info);
        mdev->mute = false;
 
@@ -200,9 +200,9 @@ static ssize_t aim_vdev_read(struct file *filp, char __user *buf,
 
                if (cnt >= rem) {
                        fh->offs = 0;
-                       spin_lock(&mdev->list_lock);
+                       spin_lock_irq(&mdev->list_lock);
                        list_del(&mbo->list);
-                       spin_unlock(&mdev->list_lock);
+                       spin_unlock_irq(&mdev->list_lock);
                        most_put_mbo(mbo);
                }
        }
@@ -394,34 +394,36 @@ static struct most_video_dev *get_aim_dev(
        struct most_interface *iface, int channel_idx)
 {
        struct most_video_dev *mdev, *tmp;
+       unsigned long flags;
 
-       spin_lock(&list_lock);
+       spin_lock_irqsave(&list_lock, flags);
        list_for_each_entry_safe(mdev, tmp, &video_devices, list) {
                if (mdev->iface == iface && mdev->ch_idx == channel_idx) {
-                       spin_unlock(&list_lock);
+                       spin_unlock_irqrestore(&list_lock, flags);
                        return mdev;
                }
        }
-       spin_unlock(&list_lock);
+       spin_unlock_irqrestore(&list_lock, flags);
        return NULL;
 }
 
 static int aim_rx_data(struct mbo *mbo)
 {
+       unsigned long flags;
        struct most_video_dev *mdev =
                get_aim_dev(mbo->ifp, mbo->hdm_channel_id);
 
        if (!mdev)
                return -EIO;
 
-       spin_lock(&mdev->list_lock);
+       spin_lock_irqsave(&mdev->list_lock, flags);
        if (unlikely(mdev->mute)) {
-               spin_unlock(&mdev->list_lock);
+               spin_unlock_irqrestore(&mdev->list_lock, flags);
                return -EIO;
        }
 
        list_add_tail(&mbo->list, &mdev->pending_mbos);
-       spin_unlock(&mdev->list_lock);
+       spin_unlock_irqrestore(&mdev->list_lock, flags);
        wake_up_interruptible(&mdev->wait_data);
        return 0;
 }
@@ -529,9 +531,9 @@ static int aim_probe_channel(struct most_interface *iface, int channel_idx,
        if (ret)
                goto err_unreg;
 
-       spin_lock(&list_lock);
+       spin_lock_irq(&list_lock);
        list_add(&mdev->list, &video_devices);
-       spin_unlock(&list_lock);
+       spin_unlock_irq(&list_lock);
        return 0;
 
 err_unreg:
@@ -552,9 +554,9 @@ static int aim_disconnect_channel(struct most_interface *iface,
                return -ENOENT;
        }
 
-       spin_lock(&list_lock);
+       spin_lock_irq(&list_lock);
        list_del(&mdev->list);
-       spin_unlock(&list_lock);
+       spin_unlock_irq(&list_lock);
 
        aim_unregister_videodev(mdev);
        v4l2_device_disconnect(&mdev->v4l2_dev);
@@ -585,17 +587,17 @@ static void __exit aim_exit(void)
         * we simulate this call here.
         * This must be fixed in core.
         */
-       spin_lock(&list_lock);
+       spin_lock_irq(&list_lock);
        list_for_each_entry_safe(mdev, tmp, &video_devices, list) {
                list_del(&mdev->list);
-               spin_unlock(&list_lock);
+               spin_unlock_irq(&list_lock);
 
                aim_unregister_videodev(mdev);
                v4l2_device_disconnect(&mdev->v4l2_dev);
                v4l2_device_put(&mdev->v4l2_dev);
-               spin_lock(&list_lock);
+               spin_lock_irq(&list_lock);
        }
-       spin_unlock(&list_lock);
+       spin_unlock_irq(&list_lock);
 
        most_deregister_aim(&aim_info);
        BUG_ON(!list_empty(&video_devices));