radio-mr800: implement proper locking

From 1773df59dc8e63ca00a27f5235c293341fd07f36 Mon Sep 17 00:00:00 2001
From: David Ellingsworth <[email protected]>
Date: Fri, 11 Sep 2009 23:21:17 -0400
Subject: [PATCH 01/10] mr800: implement proper locking

---
drivers/media/radio/radio-mr800.c | 181 ++++++++++++++++++++++---------------

1 files changed, 106 insertions(+), 75 deletions(-)

index 575bf9d..8e96c8a 100644
@@ -168,11 +168,7 @@ static int amradio_set_mute(struct amradio_device *radio, char argument)
    int retval;
    int size;
 
-    /* safety check */
-    if (radio->removed)
-        return -EIO;
-
-    mutex_lock(&radio->lock);
+    BUG_ON(!mutex_is_locked(&radio->lock));
 
    radio->buffer[0] = 0x00;
    radio->buffer[1] = 0x55;

@@ -186,15 +182,11 @@ static int amradio_set_mute(struct amradio_device *radio, char argument)
    retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
        (void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
 
-    if (retval < 0 || size != BUFFER_LENGTH) {
-        mutex_unlock(&radio->lock);
+    if (retval < 0 || size != BUFFER_LENGTH)
        return retval;
-    }
 
    radio->muted = argument;
 
-    mutex_unlock(&radio->lock);
-
    return retval;

}

@@ -205,11 +197,7 @@ static int amradio_setfreq(struct amradio_device *radio, int freq)

    int size;
    unsigned short freq_send = 0x10 + (freq >> 3) / 25;

- /* safety check */
- if (radio->removed)
- return -EIO;
-
- mutex_lock(&radio->lock);
+ BUG_ON(!mutex_is_locked(&radio->lock));

    radio->buffer[0] = 0x00;
    radio->buffer[1] = 0x55;
@@ -223,10 +211,8 @@ static int amradio_setfreq(struct amradio_device *radio, int freq)
    retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
        (void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);

- if (retval < 0 || size != BUFFER_LENGTH) {
- mutex_unlock(&radio->lock);
+ if (retval < 0 || size != BUFFER_LENGTH)

        return retval;

- }

    /* frequency is calculated from freq_send and placed in first 2 
bytes */
    radio->buffer[0] = (freq_send >> 8) & 0xff;
@@ -240,13 +226,6 @@ static int amradio_setfreq(struct amradio_device *radio, int freq)
    retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
        (void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);

- if (retval < 0 || size != BUFFER_LENGTH) {
- mutex_unlock(&radio->lock);
- return retval;
- }
-
- mutex_unlock(&radio->lock);
-

    return retval;
}

@@ -255,11 +234,7 @@ static int amradio_set_stereo(struct amradio_device *radio, char argument)

    int retval;
    int size;

- /* safety check */
- if (radio->removed)
- return -EIO;
-
- mutex_lock(&radio->lock);
+ BUG_ON(!mutex_is_locked(&radio->lock));

    radio->buffer[0] = 0x00;
    radio->buffer[1] = 0x55;

@@ -275,14 +250,11 @@ static int amradio_set_stereo(struct amradio_device *radio, char argument)

    if (retval < 0 || size != BUFFER_LENGTH) {
        radio->stereo = -1;
-        mutex_unlock(&radio->lock);
        return retval;
    }

    radio->stereo = 1;

- mutex_unlock(&radio->lock);
-

    return retval;
}

@@ -325,12 +297,18 @@ static int vidioc_g_tuner(struct file *file, void *priv,

    struct amradio_device *radio = video_get_drvdata(video_devdata(file));
    int retval;

+ mutex_lock(&radio->lock);
+

    /* safety check */

- if (radio->removed)
- return -EIO;
+ if (radio->removed) {
+ retval = -EIO;
+ goto unlock;
+ }

- if (v->index > 0)
- return -EINVAL;
+ if (v->index > 0) {
+ retval = -EINVAL;
+ goto unlock;
+ }

/* TODO: Add function which look is signal stereo or not
* amradio_getstat(radio);
@@ -357,7 +335,10 @@ static int vidioc_g_tuner(struct file *file, void *priv,

        v->audmode = V4L2_TUNER_MODE_MONO;
    v->signal = 0xffff;     /* Can't get the signal strength, sad.. */
    v->afc = 0; /* Don't know what is this */

- return 0;
+
+unlock:
+ mutex_unlock(&radio->lock);
+ return retval;
}

/* vidioc_s_tuner - set tuner attributes */
@@ -367,12 +348,18 @@ static int vidioc_s_tuner(struct file *file, void *priv,

    struct amradio_device *radio = video_get_drvdata(video_devdata(file));
    int retval;

+ mutex_lock(&radio->lock);
+

    /* safety check */

- if (radio->removed)
- return -EIO;
+ if (radio->removed) {
+ retval = -EIO;
+ goto unlock;
+ }

- if (v->index > 0)
- return -EINVAL;
+ if (v->index > 0) {
+ retval = -EINVAL;
+ goto unlock;
+ }

    /* mono/stereo selector */
    switch (v->audmode) {
@@ -389,10 +376,12 @@ static int vidioc_s_tuner(struct file *file, void *priv,
                "set stereo failed\n");
        break;
    default:
-        return -EINVAL;
+        retval = -EINVAL;
    }

- return 0;
+unlock:
+ mutex_unlock(&radio->lock);
+ return retval;
}

/* vidioc_s_frequency - set tuner radio frequency */
@@ -402,19 +391,24 @@ static int vidioc_s_frequency(struct file *file, void *priv,

    struct amradio_device *radio = video_get_drvdata(video_devdata(file));
    int retval;

+ mutex_lock(&radio->lock);
+

    /* safety check */

- if (radio->removed)
- return -EIO;
+ if (radio->removed) {
+ retval = -EIO;
+ goto unlock;
+ }

-    mutex_lock(&radio->lock);
    radio->curfreq = f->frequency;

- mutex_unlock(&radio->lock);

    retval = amradio_setfreq(radio, radio->curfreq);
    if (retval < 0)
        amradio_dev_warn(&radio->videodev->dev,
            "set frequency failed\n");

- return 0;
+
+unlock:
+ mutex_unlock(&radio->lock);
+ return retval;
}

/* vidioc_g_frequency - get tuner radio frequency */
@@ -422,14 +416,22 @@ static int vidioc_g_frequency(struct file *file, void *priv,
struct v4l2_frequency *f)

{
    struct amradio_device *radio = video_get_drvdata(video_devdata(file));

+ int retval = 0;
+
+ mutex_lock(&radio->lock);

    /* safety check */

- if (radio->removed)
- return -EIO;
+ if (radio->removed) {
+ retval = -EIO;
+ goto unlock;
+ }

    f->type = V4L2_TUNER_RADIO;
    f->frequency = radio->curfreq;

- return 0;
+
+unlock:
+ mutex_unlock(&radio->lock);
+ return retval;
}

/* vidioc_queryctrl - enumerate control items */
@@ -449,17 +451,26 @@ static int vidioc_g_ctrl(struct file *file, void *priv,
struct v4l2_control *ctrl)

{
    struct amradio_device *radio = video_get_drvdata(video_devdata(file));

+ int retval = -EINVAL;
+
+ mutex_lock(&radio->lock);

    /* safety check */

- if (radio->removed)
- return -EIO;
+ if (radio->removed) {
+ retval = -EIO;
+ goto unlock;
+ }

    switch (ctrl->id) {
    case V4L2_CID_AUDIO_MUTE:
        ctrl->value = radio->muted;
-        return 0;
+        retval = 0;
+        break;
    }

- return -EINVAL;
+
+unlock:
+ mutex_unlock(&radio->lock);
+ return retval;
}

/* vidioc_s_ctrl - set the value of a control */
@@ -467,11 +478,15 @@ static int vidioc_s_ctrl(struct file *file, void *priv,
struct v4l2_control *ctrl)

{
    struct amradio_device *radio = video_get_drvdata(video_devdata(file));

- int retval;
+ int retval = -EINVAL;
+
+ mutex_lock(&radio->lock);

    /* safety check */

- if (radio->removed)
- return -EIO;
+ if (radio->removed) {
+ retval = -EIO;
+ goto unlock;
+ }

    switch (ctrl->id) {
    case V4L2_CID_AUDIO_MUTE:
@@ -480,19 +495,20 @@ static int vidioc_s_ctrl(struct file *file, void *priv,
            if (retval < 0) {
                amradio_dev_warn(&radio->videodev->dev,
                    "amradio_stop failed\n");
-                return -1;
            }
        } else {
            retval = amradio_set_mute(radio, AMRADIO_START);
            if (retval < 0) {
                amradio_dev_warn(&radio->videodev->dev,
                    "amradio_start failed\n");
-                return -1;
            }
        }
-        return 0;
+        break;
    }

- return -EINVAL;
+
+unlock:
+ mutex_unlock(&radio->lock);
+ return retval;
}

/* vidioc_g_audio - get audio attributes */
@@ -535,9 +551,14 @@ static int vidioc_s_input(struct file *filp, void *priv, unsigned int i) static int usb_amradio_open(struct file *file)

{
    struct amradio_device *radio = video_get_drvdata(video_devdata(file));

- int retval;
+ int retval = 0;

- lock_kernel();
+ mutex_lock(&radio->lock);
+
+ if (radio->removed) {
+ retval = -EIO;
+ goto unlock;
+ }

    radio->users = 1;
    radio->muted = 1;
@@ -547,8 +568,7 @@ static int usb_amradio_open(struct file *file)
        amradio_dev_warn(&radio->videodev->dev,
            "radio did not start up properly\n");
        radio->users = 0;
-        unlock_kernel();
-        return -EIO;
+        goto unlock;
    }

    retval = amradio_set_stereo(radio, WANT_STEREO);
@@ -561,22 +581,25 @@ static int usb_amradio_open(struct file *file)
        amradio_dev_warn(&radio->videodev->dev,
            "set frequency failed\n");

- unlock_kernel();
- return 0;
+unlock:
+ mutex_unlock(&radio->lock);
+ return retval;
}

/*close device */
static int usb_amradio_close(struct file *file)

{
    struct amradio_device *radio = video_get_drvdata(video_devdata(file));

- int retval;
-
- if (!radio)
- return -ENODEV;
+ int retval = 0;

    mutex_lock(&radio->lock);

+
+ if (radio->removed) {
+ retval = -EIO;
+ goto unlock;
+ }
+

    radio->users = 0;

- mutex_unlock(&radio->lock);

    if (!radio->removed) {
        retval = amradio_set_mute(radio, AMRADIO_STOP);
@@ -585,7 +608,9 @@ static int usb_amradio_close(struct file *file)
                "amradio_stop failed\n");
    }

- return 0;
+unlock:
+ mutex_unlock(&radio->lock);
+ return retval;
}

/* Suspend device - stop device. Need to be checked and fixed */
@@ -594,12 +619,15 @@ static int usb_amradio_suspend(struct usb_interface *intf, pm_message_t message)

    struct amradio_device *radio = usb_get_intfdata(intf);
    int retval;

+ mutex_lock(&radio->lock);
+

    retval = amradio_set_mute(radio, AMRADIO_STOP);
    if (retval < 0)
        dev_warn(&intf->dev, "amradio_stop failed\n");

    dev_info(&intf->dev, "going into suspend..\n");

+    mutex_unlock(&radio->lock);
    return 0;
}

@@ -609,12 +637,15 @@ static int usb_amradio_resume(struct usb_interface *intf)

    struct amradio_device *radio = usb_get_intfdata(intf);
    int retval;

+ mutex_lock(&radio->lock);
+

    retval = amradio_set_mute(radio, AMRADIO_START);
    if (retval < 0)
        dev_warn(&intf->dev, "amradio_start failed\n");

    dev_info(&intf->dev, "coming out of suspend..\n");

+    mutex_unlock(&radio->lock);
    return 0;
}

1.6.3.3

From: David Ellingsworth <[email protected]>
Date: Fri, 11 Sep 2009 23:21:17 -0400
Subject: [PATCH 01/10] mr800: implement proper locking

---
 drivers/media/radio/radio-mr800.c |  181 ++++++++++++++++++++++---------------
 1 files changed, 106 insertions(+), 75 deletions(-)

1.6.3.3