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Commit 8c873d31 authored by Devin Heitmueller's avatar Devin Heitmueller Committed by Mauro Carvalho Chehab
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V4L/DVB (12744): em28xx: restructure fh/dev locking to handle both video and vbi 

The current locking infrastructure didn't support having multiple fds accessing
the device (such as video and vbi).  Rework the locking infrastructure,
borrowing the design from cx88.

This work was sponsored by EyeMagnet Limited.
Signed-off-by: default avatarDevin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent 91f6dcec
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Inline Side-by-side
Showing with 102 additions and 90 deletions
drivers/media/video/em28xx/em28xx-video.c
View file @ 8c873d31
...@@ -833,34 +833,63 @@ static void video_mux(struct em28xx *dev, int index) ...@@ -833,34 +833,63 @@ static void video_mux(struct em28xx *dev, int index)
} }
/* Usage lock check functions */ /* Usage lock check functions */
static int res_get(struct em28xx_fh *fh) static int res_get(struct em28xx_fh *fh, unsigned int bit)
{ {
struct em28xx *dev = fh->dev; struct em28xx *dev = fh->dev;
int rc = 0;
/* This instance already has stream_on */ if (fh->resources & bit)
if (fh->stream_on) /* have it already allocated */
return rc; return 1;
if (dev->stream_on) /* is it free? */
return -EBUSY; mutex_lock(&dev->lock);
if (dev->resources & bit) {
/* no, someone else uses it */
mutex_unlock(&dev->lock);
return 0;
}
/* it's free, grab it */
fh->resources |= bit;
dev->resources |= bit;
em28xx_videodbg("res: get %d\n", bit);
mutex_unlock(&dev->lock);
return 1;
}
dev->stream_on = 1; static int res_check(struct em28xx_fh *fh, unsigned int bit)
fh->stream_on = 1; {
return rc; return (fh->resources & bit);
} }
static int res_check(struct em28xx_fh *fh) static int res_locked(struct em28xx *dev, unsigned int bit)
{ {
return fh->stream_on; return (dev->resources & bit);
} }
static void res_free(struct em28xx_fh *fh) static void res_free(struct em28xx_fh *fh, unsigned int bits)
{ {
struct em28xx *dev = fh->dev; struct em28xx *dev = fh->dev;
fh->stream_on = 0; BUG_ON((fh->resources & bits) != bits);
dev->stream_on = 0;
mutex_lock(&dev->lock);
fh->resources &= ~bits;
dev->resources &= ~bits;
em28xx_videodbg("res: put %d\n", bits);
mutex_unlock(&dev->lock);
}
static int get_ressource(struct em28xx_fh *fh)
{
switch (fh->type) {
case V4L2_BUF_TYPE_VIDEO_CAPTURE:
return EM28XX_RESOURCE_VIDEO;
case V4L2_BUF_TYPE_VBI_CAPTURE:
return EM28XX_RESOURCE_VBI;
default:
BUG();
return 0;
}
} }
/* /*
...@@ -1103,12 +1132,6 @@ static int vidioc_s_fmt_vid_cap(struct file *file, void *priv, ...@@ -1103,12 +1132,6 @@ static int vidioc_s_fmt_vid_cap(struct file *file, void *priv,
goto out; goto out;
} }
if (dev->stream_on && !fh->stream_on) {
em28xx_errdev("%s device in use by another fh\n", __func__);
rc = -EBUSY;
goto out;
}
rc = em28xx_set_video_format(dev, f->fmt.pix.pixelformat, rc = em28xx_set_video_format(dev, f->fmt.pix.pixelformat,
f->fmt.pix.width, f->fmt.pix.height); f->fmt.pix.width, f->fmt.pix.height);
...@@ -1668,24 +1691,25 @@ static int vidioc_streamon(struct file *file, void *priv, ...@@ -1668,24 +1691,25 @@ static int vidioc_streamon(struct file *file, void *priv,
{ {
struct em28xx_fh *fh = priv; struct em28xx_fh *fh = priv;
struct em28xx *dev = fh->dev; struct em28xx *dev = fh->dev;
int rc; int rc = -EINVAL;
rc = check_dev(dev); rc = check_dev(dev);
if (rc < 0) if (rc < 0)
return rc; return rc;
if (unlikely(type != fh->type))
return -EINVAL;
mutex_lock(&dev->lock); em28xx_videodbg("vidioc_streamon fh=%p t=%d fh->res=%d dev->res=%d\n",
rc = res_get(fh); fh, type, fh->resources, dev->resources);
if (likely(rc >= 0)) { if (unlikely(!res_get(fh,get_ressource(fh))))
if (fh->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) return -EBUSY;
rc = videobuf_streamon(&fh->vb_vidq);
else if (fh->type == V4L2_BUF_TYPE_VBI_CAPTURE)
rc = videobuf_streamon(&fh->vb_vbiq);
}
mutex_unlock(&dev->lock); if (fh->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
rc = videobuf_streamon(&fh->vb_vidq);
else if (fh->type == V4L2_BUF_TYPE_VBI_CAPTURE)
rc = videobuf_streamon(&fh->vb_vbiq);
return rc; return rc;
} }
...@@ -1707,16 +1731,16 @@ static int vidioc_streamoff(struct file *file, void *priv, ...@@ -1707,16 +1731,16 @@ static int vidioc_streamoff(struct file *file, void *priv,
if (type != fh->type) if (type != fh->type)
return -EINVAL; return -EINVAL;
mutex_lock(&dev->lock); em28xx_videodbg("vidioc_streamoff fh=%p t=%d fh->res=%d dev->res=%d\n",
fh, type, fh->resources, dev->resources);
if (fh->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) if (fh->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
videobuf_streamoff(&fh->vb_vidq); videobuf_streamoff(&fh->vb_vidq);
else if (fh->type == V4L2_BUF_TYPE_VBI_CAPTURE) res_free(fh, EM28XX_RESOURCE_VIDEO);
} else if (fh->type == V4L2_BUF_TYPE_VBI_CAPTURE) {
videobuf_streamoff(&fh->vb_vbiq); videobuf_streamoff(&fh->vb_vbiq);
res_free(fh, EM28XX_RESOURCE_VBI);
res_free(fh); }
mutex_unlock(&dev->lock);
return 0; return 0;
} }
...@@ -2095,17 +2119,16 @@ static int em28xx_v4l2_open(struct file *filp) ...@@ -2095,17 +2119,16 @@ static int em28xx_v4l2_open(struct file *filp)
else else
field = V4L2_FIELD_INTERLACED; field = V4L2_FIELD_INTERLACED;
if (fh->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) videobuf_queue_vmalloc_init(&fh->vb_vidq, &em28xx_video_qops,
videobuf_queue_vmalloc_init(&fh->vb_vidq, &em28xx_video_qops, NULL, &dev->slock,
NULL, &dev->slock, fh->type, field, V4L2_BUF_TYPE_VIDEO_CAPTURE, field,
sizeof(struct em28xx_buffer), fh); sizeof(struct em28xx_buffer), fh);
if (fh->type == V4L2_BUF_TYPE_VBI_CAPTURE) videobuf_queue_vmalloc_init(&fh->vb_vbiq, &em28xx_vbi_qops,
videobuf_queue_vmalloc_init(&fh->vb_vbiq, &em28xx_vbi_qops, NULL, &dev->slock,
NULL, &dev->slock, V4L2_BUF_TYPE_VBI_CAPTURE,
V4L2_BUF_TYPE_VBI_CAPTURE, V4L2_FIELD_SEQ_TB,
V4L2_FIELD_SEQ_TB, sizeof(struct em28xx_buffer), fh);
sizeof(struct em28xx_buffer), fh);
mutex_unlock(&dev->lock); mutex_unlock(&dev->lock);
...@@ -2162,20 +2185,21 @@ static int em28xx_v4l2_close(struct file *filp) ...@@ -2162,20 +2185,21 @@ static int em28xx_v4l2_close(struct file *filp)
em28xx_videodbg("users=%d\n", dev->users); em28xx_videodbg("users=%d\n", dev->users);
if (res_check(fh, EM28XX_RESOURCE_VIDEO)) {
mutex_lock(&dev->lock);
if (res_check(fh))
res_free(fh);
if (fh->type == V4L2_BUF_TYPE_VIDEO_CAPTURE && dev->users == 1) {
videobuf_stop(&fh->vb_vidq); videobuf_stop(&fh->vb_vidq);
videobuf_mmap_free(&fh->vb_vidq); res_free(fh, EM28XX_RESOURCE_VIDEO);
}
if (res_check(fh, EM28XX_RESOURCE_VBI)) {
videobuf_stop(&fh->vb_vbiq);
res_free(fh, EM28XX_RESOURCE_VBI);
}
if(dev->users == 1) {
/* the device is already disconnect, /* the device is already disconnect,
free the remaining resources */ free the remaining resources */
if (dev->state & DEV_DISCONNECTED) { if (dev->state & DEV_DISCONNECTED) {
em28xx_release_resources(dev); em28xx_release_resources(dev);
mutex_unlock(&dev->lock);
kfree(dev); kfree(dev);
return 0; return 0;
} }
...@@ -2197,15 +2221,11 @@ static int em28xx_v4l2_close(struct file *filp) ...@@ -2197,15 +2221,11 @@ static int em28xx_v4l2_close(struct file *filp)
} }
} }
if (fh->type == V4L2_BUF_TYPE_VBI_CAPTURE) { videobuf_mmap_free(&fh->vb_vidq);
videobuf_stop(&fh->vb_vbiq); videobuf_mmap_free(&fh->vb_vbiq);
videobuf_mmap_free(&fh->vb_vbiq);
}
kfree(fh); kfree(fh);
dev->users--; dev->users--;
wake_up_interruptible_nr(&dev->open, 1); wake_up_interruptible_nr(&dev->open, 1);
mutex_unlock(&dev->lock);
return 0; return 0;
} }
...@@ -2230,12 +2250,8 @@ em28xx_v4l2_read(struct file *filp, char __user *buf, size_t count, ...@@ -2230,12 +2250,8 @@ em28xx_v4l2_read(struct file *filp, char __user *buf, size_t count,
*/ */
if (fh->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) { if (fh->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
mutex_lock(&dev->lock); if (res_locked(dev, EM28XX_RESOURCE_VIDEO))
rc = res_get(fh); return -EBUSY;
mutex_unlock(&dev->lock);
if (unlikely(rc < 0))
return rc;
return videobuf_read_stream(&fh->vb_vidq, buf, count, pos, 0, return videobuf_read_stream(&fh->vb_vidq, buf, count, pos, 0,
filp->f_flags & O_NONBLOCK); filp->f_flags & O_NONBLOCK);
...@@ -2243,9 +2259,8 @@ em28xx_v4l2_read(struct file *filp, char __user *buf, size_t count, ...@@ -2243,9 +2259,8 @@ em28xx_v4l2_read(struct file *filp, char __user *buf, size_t count,
if (fh->type == V4L2_BUF_TYPE_VBI_CAPTURE) { if (fh->type == V4L2_BUF_TYPE_VBI_CAPTURE) {
mutex_lock(&dev->lock); if (!res_get(fh, EM28XX_RESOURCE_VBI))
rc = res_get(fh); return -EBUSY;
mutex_unlock(&dev->lock);
return videobuf_read_stream(&fh->vb_vbiq, buf, count, pos, 0, return videobuf_read_stream(&fh->vb_vbiq, buf, count, pos, 0,
filp->f_flags & O_NONBLOCK); filp->f_flags & O_NONBLOCK);
...@@ -2268,19 +2283,17 @@ static unsigned int em28xx_v4l2_poll(struct file *filp, poll_table *wait) ...@@ -2268,19 +2283,17 @@ static unsigned int em28xx_v4l2_poll(struct file *filp, poll_table *wait)
if (rc < 0) if (rc < 0)
return rc; return rc;
mutex_lock(&dev->lock); if (fh->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
rc = res_get(fh); if (!res_get(fh, EM28XX_RESOURCE_VIDEO))
mutex_unlock(&dev->lock); return POLLERR;
if (unlikely(rc < 0))
return POLLERR;
if (fh->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
return videobuf_poll_stream(filp, &fh->vb_vidq, wait); return videobuf_poll_stream(filp, &fh->vb_vidq, wait);
else if (fh->type == V4L2_BUF_TYPE_VBI_CAPTURE) } else if (fh->type == V4L2_BUF_TYPE_VBI_CAPTURE) {
if (!res_get(fh, EM28XX_RESOURCE_VBI))
return POLLERR;
return videobuf_poll_stream(filp, &fh->vb_vbiq, wait); return videobuf_poll_stream(filp, &fh->vb_vbiq, wait);
else } else {
return POLLERR; return POLLERR;
}
} }
/* /*
...@@ -2296,13 +2309,6 @@ static int em28xx_v4l2_mmap(struct file *filp, struct vm_area_struct *vma) ...@@ -2296,13 +2309,6 @@ static int em28xx_v4l2_mmap(struct file *filp, struct vm_area_struct *vma)
if (rc < 0) if (rc < 0)
return rc; return rc;
mutex_lock(&dev->lock);
rc = res_get(fh);
mutex_unlock(&dev->lock);
if (unlikely(rc < 0))
return rc;
if (fh->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) if (fh->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
rc = videobuf_mmap_mapper(&fh->vb_vidq, vma); rc = videobuf_mmap_mapper(&fh->vb_vidq, vma);
else if (fh->type == V4L2_BUF_TYPE_VBI_CAPTURE) else if (fh->type == V4L2_BUF_TYPE_VBI_CAPTURE)
......
drivers/media/video/em28xx/em28xx.h
View file @ 8c873d31
...@@ -444,6 +444,10 @@ enum em28xx_dev_state { ...@@ -444,6 +444,10 @@ enum em28xx_dev_state {
#define EM28XX_AUDIO 0x10 #define EM28XX_AUDIO 0x10
#define EM28XX_DVB 0x20 #define EM28XX_DVB 0x20
/* em28xx resource types (used for res_get/res_lock etc */
#define EM28XX_RESOURCE_VIDEO 0x01
#define EM28XX_RESOURCE_VBI 0x02
struct em28xx_audio { struct em28xx_audio {
char name[50]; char name[50];
char *transfer_buffer[EM28XX_AUDIO_BUFS]; char *transfer_buffer[EM28XX_AUDIO_BUFS];
...@@ -464,8 +468,8 @@ struct em28xx; ...@@ -464,8 +468,8 @@ struct em28xx;
struct em28xx_fh { struct em28xx_fh {
struct em28xx *dev; struct em28xx *dev;
unsigned int stream_on:1; /* Locks streams */
int radio; int radio;
unsigned int resources;
struct videobuf_queue vb_vidq; struct videobuf_queue vb_vidq;
struct videobuf_queue vb_vbiq; struct videobuf_queue vb_vbiq;
...@@ -495,7 +499,6 @@ struct em28xx { ...@@ -495,7 +499,6 @@ struct em28xx {
/* Vinmode/Vinctl used at the driver */ /* Vinmode/Vinctl used at the driver */
int vinmode, vinctl; int vinmode, vinctl;
unsigned int stream_on:1; /* Locks streams */
unsigned int has_audio_class:1; unsigned int has_audio_class:1;
unsigned int has_alsa_audio:1; unsigned int has_alsa_audio:1;
...@@ -563,6 +566,9 @@ struct em28xx { ...@@ -563,6 +566,9 @@ struct em28xx {
struct video_device *vbi_dev; struct video_device *vbi_dev;
struct video_device *radio_dev; struct video_device *radio_dev;
/* resources in use */
unsigned int resources;
unsigned char eedata[256]; unsigned char eedata[256];
/* Isoc control struct */ /* Isoc control struct */
......
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