pvrusb2: Implement input selection enforcement

From: Mike Isely <isely@pobox.com>


In the pvrusb2 driver, different interfaces (e.g. V4L, DVB) have
different abilities to handle various inputs.  While the driver core
can handle them all, the interfaces currently are not able to do this.
Also, due to the fact that the DVB interface is directly touching the
hardware, this limits what the V4L side can possibly do with digital
reception, i.e. it has no means to control the digital tuner.  This
change implements a critical new feature in the driver where the
interface instance can declare which inputs it is able to handle.  The
driver core then uses this information to narrow the list of legal
input selections based on which interface(s) are active at the moment.
The driver core will also perform an input switch (and consequently a
mode switch) if the new narrowed list doesn't include the current
mode.  The overall effect of all of this is that now when a user opens
the DVB interface, then the driver flips to dtv mode and likewise when
the V4L video device is opened, the driver will disallow dtv
selection.  This also cleans up the handling of the V4L radio device -
open that device and the driver will narrow to just the radio input.
If the narrowing request results in the null set, e.g. attempting to
narrow to dtv only while streaming analog, then the operation is
disallowed and the caller gets an error.  This has the effect of
locking out mutually incompatible interfaces.  For example, an attempt
to operate a V4L interface will definitively fail when DVB is active.
Thus we have locking and enforcement between the DVB and V4L sides.
Hopefully at some point in the future we can expand the supported
inputs in each interface, and at that point, the interface can just
declare an expanded set of handled inputs and everything should
continue to work itself out.  This is a significant feature; it
finally enables cooperative handling of pvrusb2-driven devices between
DVB and V4L.

Signed-off-by: Mike Isely <isely@pobox.com>

7 files changed, 245 insertions, 86 deletions

diff --git a/linux/drivers/media/video/pvrusb2/pvrusb2-context.c b/linux/drivers/media/video/pvrusb2/pvrusb2-context.c
index ecbb23f3d..1a2485f5d 100644
--- a/linux/drivers/media/video/pvrusb2/pvrusb2-context.c
+++ b/linux/drivers/media/video/pvrusb2/pvrusb2-context.c
@@ -247,6 +247,22 @@ struct pvr2_context *pvr2_context_create(
 }
 
 
+static void pvr2_context_reset_input_limits(struct pvr2_context *mp)
+{
+	unsigned int tmsk,mmsk;
+	struct pvr2_channel *cp;
+	struct pvr2_hdw *hdw = mp->hdw;
+	mmsk = pvr2_hdw_get_input_available(hdw);
+	tmsk = mmsk;
+	for (cp = mp->mc_first; cp; cp = cp->mc_next) {
+		if (!cp->input_mask) continue;
+		tmsk &= cp->input_mask;
+	}
+	pvr2_hdw_set_input_allowed(hdw,mmsk,tmsk);
+	pvr2_hdw_commit_ctl(hdw);
+}
+
+
 static void pvr2_context_enter(struct pvr2_context *mp)
 {
 	mutex_lock(&mp->mutex);
@@ -302,7 +318,9 @@ void pvr2_channel_done(struct pvr2_channel *cp)
 {
 	struct pvr2_context *mp = cp->mc_head;
 	pvr2_context_enter(mp);
+	cp->input_mask = 0;
 	pvr2_channel_disclaim_stream(cp);
+	pvr2_context_reset_input_limits(mp);
 	if (cp->mc_next) {
 		cp->mc_next->mc_prev = cp->mc_prev;
 	} else {
@@ -318,6 +336,57 @@ void pvr2_channel_done(struct pvr2_channel *cp)
 }
 
 
+int pvr2_channel_limit_inputs(struct pvr2_channel *cp,unsigned int cmsk)
+{
+	unsigned int tmsk,mmsk;
+	int ret = 0;
+	struct pvr2_channel *p2;
+	struct pvr2_hdw *hdw = cp->hdw;
+
+	mmsk = pvr2_hdw_get_input_available(hdw);
+	cmsk &= mmsk;
+	if (cmsk == cp->input_mask) {
+		/* No change; nothing to do */
+		return 0;
+	}
+
+	pvr2_context_enter(cp->mc_head);
+	do {
+		if (!cmsk) {
+			cp->input_mask = 0;
+			pvr2_context_reset_input_limits(cp->mc_head);
+			break;
+		}
+		tmsk = mmsk;
+		for (p2 = cp->mc_head->mc_first; p2; p2 = p2->mc_next) {
+			if (p2 == cp) continue;
+			if (!p2->input_mask) continue;
+			tmsk &= p2->input_mask;
+		}
+		if (!(tmsk & cmsk)) {
+			ret = -EPERM;
+			break;
+		}
+		tmsk &= cmsk;
+		if ((ret = pvr2_hdw_set_input_allowed(hdw,mmsk,tmsk)) != 0) {
+			/* Internal failure changing allowed list; probably
+			   should not happen, but react if it does. */
+			break;
+		}
+		cp->input_mask = cmsk;
+		pvr2_hdw_commit_ctl(hdw);
+	} while (0);
+	pvr2_context_exit(cp->mc_head);
+	return ret;
+}
+
+
+unsigned int pvr2_channel_get_limited_inputs(struct pvr2_channel *cp)
+{
+	return cp->input_mask;
+}
+
+
 int pvr2_channel_claim_stream(struct pvr2_channel *cp,
 			      struct pvr2_context_stream *sp)
 {
diff --git a/linux/drivers/media/video/pvrusb2/pvrusb2-context.h b/linux/drivers/media/video/pvrusb2/pvrusb2-context.h
index 3ac224c5d..c6e25e154 100644
--- a/linux/drivers/media/video/pvrusb2/pvrusb2-context.h
+++ b/linux/drivers/media/video/pvrusb2/pvrusb2-context.h
@@ -70,6 +70,7 @@ struct pvr2_channel {
 	struct pvr2_channel *mc_prev;
 	struct pvr2_context_stream *stream;
 	struct pvr2_hdw *hdw;
+	unsigned int input_mask;
 	void (*check_func)(struct pvr2_channel *);
 };
 
@@ -80,6 +81,8 @@ void pvr2_context_disconnect(struct pvr2_context *);
 
 void pvr2_channel_init(struct pvr2_channel *,struct pvr2_context *);
 void pvr2_channel_done(struct pvr2_channel *);
+int pvr2_channel_limit_inputs(struct pvr2_channel *,unsigned int);
+unsigned int pvr2_channel_get_limited_inputs(struct pvr2_channel *);
 int pvr2_channel_claim_stream(struct pvr2_channel *,
 			      struct pvr2_context_stream *);
 struct pvr2_ioread *pvr2_channel_create_mpeg_stream(
diff --git a/linux/drivers/media/video/pvrusb2/pvrusb2-dvb.c b/linux/drivers/media/video/pvrusb2/pvrusb2-dvb.c
index e5991f783..3df569d7a 100644
--- a/linux/drivers/media/video/pvrusb2/pvrusb2-dvb.c
+++ b/linux/drivers/media/video/pvrusb2/pvrusb2-dvb.c
@@ -249,26 +249,10 @@ static int pvr2_dvb_stop_feed(struct dvb_demux_feed *dvbdmxfeed)
 
 static int pvr2_dvb_bus_ctrl(struct dvb_frontend *fe, int acquire)
 {
-	/* TO DO: This function will call into the core and request for
-	 * input to be set to 'dtv' if (acquire) and if it isn't set already.
-	 *
-	 * If (!acquire) then we should do nothing -- don't switch inputs
-	 * again unless the analog side of the driver requests the bus.
-	 */
-#if 0
 	struct pvr2_dvb_adapter *adap = fe->dvb->priv;
-	struct pvr2_hdw *hdw = adap->pvr->hdw;
-	int ret = 0;
-
-	ret = pvr2_ctrl_set_value(pvr2_hdw_get_ctrl_by_id(hdw,
-				  PVR2_CID_INPUT),
-				  acquire ? PVR2_CVAL_INPUT_DTV :
-					    PVR2_CVAL_INPUT_TV);
-	pvr2_hdw_commit_ctl(hdw);
-	return ret;
-#else
-	return 0;
-#endif
+	return pvr2_channel_limit_inputs(
+	    &adap->channel,
+	    (acquire ? (1 << PVR2_CVAL_INPUT_DTV) : 0));
 }
 
 static int pvr2_dvb_adapter_init(struct pvr2_dvb_adapter *adap)
@@ -338,32 +322,26 @@ static int pvr2_dvb_frontend_init(struct pvr2_dvb_adapter *adap)
 {
 	struct pvr2_hdw *hdw = adap->channel.hdw;
 	struct pvr2_dvb_props *dvb_props = hdw->hdw_desc->dvb_props;
-	int ret;
+	int ret = 0;
 
 	if (dvb_props == NULL) {
 		err("fe_props not defined!");
 		return -EINVAL;
 	}
 
-	/* FIXME: This code should be moved into the core,
-	 * and should only be called if we don't already have
-	 * control of the bus.
-	 *
-	 * We can't call "pvr2_dvb_bus_ctrl(adap->fe, 1)" from here,
-	 * because adap->fe isn't defined yet.
-	 */
-	ret = pvr2_ctrl_set_value(pvr2_hdw_get_ctrl_by_id(hdw,
-							  PVR2_CID_INPUT),
-				  PVR2_CVAL_INPUT_DTV);
-	if (ret != 0)
+	ret = pvr2_channel_limit_inputs(
+	    &adap->channel,
+	    (1 << PVR2_CVAL_INPUT_DTV));
+	if (ret) {
+		err("failed to grab control of dtv input (code=%d)",
+		    ret);
 		return ret;
-
-	pvr2_hdw_commit_ctl(hdw);
-
+	}
 
 	if (dvb_props->frontend_attach == NULL) {
 		err("frontend_attach not defined!");
-		return -EINVAL;
+		ret = -EINVAL;
+		goto done;
 	}
 
 	if ((dvb_props->frontend_attach(adap) == 0) && (adap->fe)) {
@@ -372,7 +350,8 @@ static int pvr2_dvb_frontend_init(struct pvr2_dvb_adapter *adap)
 			err("frontend registration failed!");
 			dvb_frontend_detach(adap->fe);
 			adap->fe = NULL;
-			return -ENODEV;
+			ret = -ENODEV;
+			goto done;
 		}
 
 		if (dvb_props->tuner_attach)
@@ -386,10 +365,13 @@ static int pvr2_dvb_frontend_init(struct pvr2_dvb_adapter *adap)
 
 	} else {
 		err("no frontend was attached!");
-		return -ENODEV;
+		ret = -ENODEV;
+		return ret;
 	}
 
-	return 0;
+ done:
+	pvr2_channel_limit_inputs(&adap->channel, 0);
+	return ret;
 }
 
 static int pvr2_dvb_frontend_exit(struct pvr2_dvb_adapter *adap)
diff --git a/linux/drivers/media/video/pvrusb2/pvrusb2-hdw-internal.h b/linux/drivers/media/video/pvrusb2/pvrusb2-hdw-internal.h
index 11ef1a9ac..44e77355f 100644
--- a/linux/drivers/media/video/pvrusb2/pvrusb2-hdw-internal.h
+++ b/linux/drivers/media/video/pvrusb2/pvrusb2-hdw-internal.h
@@ -352,8 +352,10 @@ struct pvr2_hdw {
 	int v4l_minor_number_vbi;
 	int v4l_minor_number_radio;
 
-	/* Bit mask of PVR2_CVAL_INPUT choices which are valid */
+	/* Bit mask of PVR2_CVAL_INPUT choices which are valid for the hardware */
 	unsigned int input_avail_mask;
+	/* Bit mask of PVR2_CVAL_INPUT choices which are currenly allowed */
+	unsigned int input_allowed_mask;
 
 	/* Location of eeprom or a negative number if none */
 	int eeprom_addr;
diff --git a/linux/drivers/media/video/pvrusb2/pvrusb2-hdw.c b/linux/drivers/media/video/pvrusb2/pvrusb2-hdw.c
index d79df167b..7ebbd69a4 100644
--- a/linux/drivers/media/video/pvrusb2/pvrusb2-hdw.c
+++ b/linux/drivers/media/video/pvrusb2/pvrusb2-hdw.c
@@ -251,6 +251,7 @@ static const struct pvr2_fx2cmd_descdef pvr2_fx2cmd_desc[] = {
 };
 
 
+static int pvr2_hdw_set_input(struct pvr2_hdw *hdw,int v);
 static void pvr2_hdw_state_sched(struct pvr2_hdw *);
 static int pvr2_hdw_state_eval(struct pvr2_hdw *);
 static void pvr2_hdw_set_cur_freq(struct pvr2_hdw *,unsigned long);
@@ -406,30 +407,12 @@ static int ctrl_get_input(struct pvr2_ctrl *cptr,int *vp)
 
 static int ctrl_check_input(struct pvr2_ctrl *cptr,int v)
 {
-	return ((1 << v) & cptr->hdw->input_avail_mask) != 0;
+	return ((1 << v) & cptr->hdw->input_allowed_mask) != 0;
 }
 
 static int ctrl_set_input(struct pvr2_ctrl *cptr,int m,int v)
 {
-	struct pvr2_hdw *hdw = cptr->hdw;
-
-	if (hdw->input_val != v) {
-		hdw->input_val = v;
-		hdw->input_dirty = !0;
-	}
-
-	/* Handle side effects - if we switch to a mode that needs the RF
-	   tuner, then select the right frequency choice as well and mark
-	   it dirty. */
-	if (hdw->input_val == PVR2_CVAL_INPUT_RADIO) {
-		hdw->freqSelector = 0;
-		hdw->freqDirty = !0;
-	} else if ((hdw->input_val == PVR2_CVAL_INPUT_TV) ||
-		   (hdw->input_val == PVR2_CVAL_INPUT_DTV)) {
-		hdw->freqSelector = 1;
-		hdw->freqDirty = !0;
-	}
-	return 0;
+	return pvr2_hdw_set_input(cptr->hdw,v);
 }
 
 static int ctrl_isdirty_input(struct pvr2_ctrl *cptr)
@@ -1934,6 +1917,7 @@ struct pvr2_hdw *pvr2_hdw_create(struct usb_interface *intf,
 	if (hdw_desc->flag_has_composite) m |= 1 << PVR2_CVAL_INPUT_COMPOSITE;
 	if (hdw_desc->flag_has_fmradio) m |= 1 << PVR2_CVAL_INPUT_RADIO;
 	hdw->input_avail_mask = m;
+	hdw->input_allowed_mask = hdw->input_avail_mask;
 
 	/* If not a hybrid device, pathway_state never changes.  So
 	   initialize it here to what it should forever be. */
@@ -4047,6 +4031,24 @@ static int pvr2_hdw_state_update(struct pvr2_hdw *hdw)
 }
 
 
+static unsigned int print_input_mask(unsigned int msk,
+				     char *buf,unsigned int acnt)
+{
+	unsigned int idx,ccnt;
+	unsigned int tcnt = 0;
+	for (idx = 0; idx < ARRAY_SIZE(control_values_input); idx++) {
+		if (!((1 << idx) & msk)) continue;
+		ccnt = scnprintf(buf+tcnt,
+				 acnt-tcnt,
+				 "%s%s",
+				 (tcnt ? ", " : ""),
+				 control_values_input[idx]);
+		tcnt += ccnt;
+	}
+	return tcnt;
+}
+
+
 static const char *pvr2_pathway_state_name(int id)
 {
 	switch (id) {
@@ -4115,6 +4117,28 @@ static unsigned int pvr2_hdw_report_unlocked(struct pvr2_hdw *hdw,int which,
 			"state: %s",
 			pvr2_get_state_name(hdw->master_state));
 	case 4: {
+		unsigned int tcnt = 0;
+		unsigned int ccnt;
+
+		ccnt = scnprintf(buf,
+				 acnt,
+				 "Hardware supported inputs: ");
+		tcnt += ccnt;
+		tcnt += print_input_mask(hdw->input_avail_mask,
+					 buf+tcnt,
+					 acnt-tcnt);
+		if (hdw->input_avail_mask != hdw->input_allowed_mask) {
+			ccnt = scnprintf(buf+tcnt,
+					 acnt-tcnt,
+					 "; allowed inputs: ");
+			tcnt += ccnt;
+			tcnt += print_input_mask(hdw->input_allowed_mask,
+						 buf+tcnt,
+						 acnt-tcnt);
+		}
+		return tcnt;
+	}
+	case 5: {
 		struct pvr2_stream_stats stats;
 		if (!hdw->vid_stream) break;
 		pvr2_stream_get_stats(hdw->vid_stream,
@@ -4352,6 +4376,74 @@ unsigned int pvr2_hdw_get_input_available(struct pvr2_hdw *hdw)
 }
 
 
+unsigned int pvr2_hdw_get_input_allowed(struct pvr2_hdw *hdw)
+{
+	return hdw->input_allowed_mask;
+}
+
+
+static int pvr2_hdw_set_input(struct pvr2_hdw *hdw,int v)
+{
+	if (hdw->input_val != v) {
+		hdw->input_val = v;
+		hdw->input_dirty = !0;
+	}
+
+	/* Handle side effects - if we switch to a mode that needs the RF
+	   tuner, then select the right frequency choice as well and mark
+	   it dirty. */
+	if (hdw->input_val == PVR2_CVAL_INPUT_RADIO) {
+		hdw->freqSelector = 0;
+		hdw->freqDirty = !0;
+	} else if ((hdw->input_val == PVR2_CVAL_INPUT_TV) ||
+		   (hdw->input_val == PVR2_CVAL_INPUT_DTV)) {
+		hdw->freqSelector = 1;
+		hdw->freqDirty = !0;
+	}
+	return 0;
+}
+
+
+int pvr2_hdw_set_input_allowed(struct pvr2_hdw *hdw,
+			       unsigned int change_mask,
+			       unsigned int change_val)
+{
+	int ret = 0;
+	unsigned int nv,m,idx;
+	LOCK_TAKE(hdw->big_lock);
+	do {
+		nv = hdw->input_allowed_mask & ~change_mask;
+		nv |= (change_val & change_mask);
+		nv &= hdw->input_avail_mask;
+		if (!nv) {
+			/* No legal modes left; return error instead. */
+			ret = -EPERM;
+			break;
+		}
+		hdw->input_allowed_mask = nv;
+		if ((1 << hdw->input_val) & hdw->input_allowed_mask) {
+			/* Current mode is still in the allowed mask, so
+			   we're done. */
+			break;
+		}
+		/* Select and switch to a mode that is still in the allowed
+		   mask */
+		if (!hdw->input_allowed_mask) {
+			/* Nothing legal; give up */
+			break;
+		}
+		m = hdw->input_allowed_mask;
+		for (idx = 0; idx < (sizeof(m) << 3); idx++) {
+			if (!((1 << idx) & m)) continue;
+			pvr2_hdw_set_input(hdw,idx);
+			break;
+		}
+	} while (0);
+	LOCK_GIVE(hdw->big_lock);
+	return ret;
+}
+
+
 /* Find I2C address of eeprom */
 static int pvr2_hdw_get_eeprom_addr(struct pvr2_hdw *hdw)
 {
diff --git a/linux/drivers/media/video/pvrusb2/pvrusb2-hdw.h b/linux/drivers/media/video/pvrusb2/pvrusb2-hdw.h
index 879a9fad7..97512a96f 100644
--- a/linux/drivers/media/video/pvrusb2/pvrusb2-hdw.h
+++ b/linux/drivers/media/video/pvrusb2/pvrusb2-hdw.h
@@ -155,6 +155,19 @@ int pvr2_hdw_commit_ctl(struct pvr2_hdw *);
  * will be according to PVR_CVAL_INPUT_xxxx definitions. */
 unsigned int pvr2_hdw_get_input_available(struct pvr2_hdw *);
 
+/* Return a bit mask of allowed input selections for this device.  Mask bits
+ * will be according to PVR_CVAL_INPUT_xxxx definitions. */
+unsigned int pvr2_hdw_get_input_allowed(struct pvr2_hdw *);
+
+/* Change the set of allowed input selections for this device.  Both
+   change_mask and change_valu are mask bits according to
+   PVR_CVAL_INPUT_xxxx definitions.  The change_mask parameter indicate
+   which settings are being changed and the change_val parameter indicates
+   whether corresponding settings are being set or cleared. */
+int pvr2_hdw_set_input_allowed(struct pvr2_hdw *,
+			       unsigned int change_mask,
+			       unsigned int change_val);
+
 /* Return name for this driver instance */
 const char *pvr2_hdw_get_driver_name(struct pvr2_hdw *);
 
diff --git a/linux/drivers/media/video/pvrusb2/pvrusb2-v4l2.c b/linux/drivers/media/video/pvrusb2/pvrusb2-v4l2.c
index 38b0ff0f5..b81bf8e7b 100644
--- a/linux/drivers/media/video/pvrusb2/pvrusb2-v4l2.c
+++ b/linux/drivers/media/video/pvrusb2/pvrusb2-v4l2.c
@@ -58,7 +58,6 @@ struct pvr2_v4l2_fh {
 	struct pvr2_v4l2_fh *vprev;
 	wait_queue_head_t wait_data;
 	int fw_mode_flag;
-	int prev_input_val;
 };
 
 struct pvr2_v4l2 {
@@ -901,20 +900,6 @@ static int pvr2_v4l2_release(struct inode *inode, struct file *file)
 	v4l2_prio_close(&vp->prio, &fhp->prio);
 	file->private_data = NULL;
 
-	/* Restore the previous input selection, if it makes sense
-	   to do so. */
-	if (fhp->dev_info->v4l_type == VFL_TYPE_RADIO) {
-		struct pvr2_ctrl *cp;
-		int pval;
-		cp = pvr2_hdw_get_ctrl_by_id(hdw,PVR2_CID_INPUT);
-		pvr2_ctrl_get_value(cp,&pval);
-		/* Only restore if we're still selecting the radio */
-		if (pval == PVR2_CVAL_INPUT_RADIO) {
-			pvr2_ctrl_set_value(cp,fhp->prev_input_val);
-			pvr2_hdw_commit_ctl(hdw);
-		}
-	}
-
 	if (fhp->vnext) {
 		fhp->vnext->vprev = fhp->vprev;
 	} else {
@@ -945,6 +930,8 @@ static int pvr2_v4l2_open(struct inode *inode, struct file *file)
 	struct pvr2_v4l2_fh *fhp;
 	struct pvr2_v4l2 *vp;
 	struct pvr2_hdw *hdw;
+	unsigned int input_mask = 0;
+	int ret = 0;
 
 	dip = container_of(video_devdata(file),struct pvr2_v4l2_dev,devbase);
 
@@ -970,6 +957,29 @@ static int pvr2_v4l2_open(struct inode *inode, struct file *file)
 	pvr2_trace(PVR2_TRACE_STRUCT,"Creating pvr_v4l2_fh id=%p",fhp);
 	pvr2_channel_init(&fhp->channel,vp->channel.mc_head);
 
+	if (dip->v4l_type == VFL_TYPE_RADIO) {
+		/* Opening device as a radio, legal input selection subset
+		   is just the radio. */
+		input_mask = (1 << PVR2_CVAL_INPUT_RADIO);
+	} else {
+		/* Opening the main V4L device, legal input selection
+		   subset includes all analog inputs. */
+		input_mask = ((1 << PVR2_CVAL_INPUT_RADIO) |
+			      (1 << PVR2_CVAL_INPUT_TV) |
+			      (1 << PVR2_CVAL_INPUT_COMPOSITE) |
+			      (1 << PVR2_CVAL_INPUT_SVIDEO));
+	}
+	ret = pvr2_channel_limit_inputs(&fhp->channel,input_mask);
+	if (ret) {
+		pvr2_channel_done(&fhp->channel);
+		pvr2_trace(PVR2_TRACE_STRUCT,
+			   "Destroying pvr_v4l2_fh id=%p (input mask error)",
+			   fhp);
+
+		kfree(fhp);
+		return ret;
+	}
+
 	fhp->vnext = NULL;
 	fhp->vprev = vp->vlast;
 	if (vp->vlast) {
@@ -980,18 +990,6 @@ static int pvr2_v4l2_open(struct inode *inode, struct file *file)
 	vp->vlast = fhp;
 	fhp->vhead = vp;
 
-	/* Opening the /dev/radioX device implies a mode switch.
-	   So execute that here.  Note that you can get the
-	   IDENTICAL effect merely by opening the normal video
-	   device and setting the input appropriately. */
-	if (dip->v4l_type == VFL_TYPE_RADIO) {
-		struct pvr2_ctrl *cp;
-		cp = pvr2_hdw_get_ctrl_by_id(hdw,PVR2_CID_INPUT);
-		pvr2_ctrl_get_value(cp,&fhp->prev_input_val);
-		pvr2_ctrl_set_value(cp,PVR2_CVAL_INPUT_RADIO);
-		pvr2_hdw_commit_ctl(hdw);
-	}
-
 	fhp->file = file;
 	file->private_data = fhp;
 	v4l2_prio_open(&vp->prio,&fhp->prio);