[linux-dvb] Re: cinergyT2: which kernel/usb module to use?

[Holger Waechtler <holger@qanu.de>]

Stefan Lucke wrote:

> Quoting Holger Waechtler:
>  
> > > :) sounds like we need the evil counter-hack to get peace...
> > >      
> > can you please try the attached patch and test if it solves your problem?
> >
> >    
> Found your mail now. Will test it this evening.
>
> The thing that puzzels me is that "pending_fe_events" is only
> incremented, neither initialized nor decremented or reset to zero.
>  
oops - sure, you are absolutely right, it should get reset in GET_EVENT 
-- this line got lost in my edits somehow. Please try the patch below. 
Keep in mind that neither this nor the event handling code in 
dvb_frontend.c is multi-client-safe, better just don't use FE_GET_EVENT 
anywhere in your application, this will also simplify porting to new API 
versions.

Holger

? build-2.4/include/linux
Index: linux/drivers/media/dvb/cinergyT2/cinergyT2.c
===================================================================
RCS file: /cvs/linuxtv/dvb-kernel/linux/drivers/media/dvb/cinergyT2/cinergyT2.c,v
retrieving revision 1.15.2.3
diff -p -u -p -u -r1.15.2.3 cinergyT2.c
--- linux/drivers/media/dvb/cinergyT2/cinergyT2.c	27 Nov 2004 19:15:22 -0000	1.15.2.3
+++ linux/drivers/media/dvb/cinergyT2/cinergyT2.c	30 Nov 2004 12:00:15 -0000
@@ -176,6 +176,7 @@ struct cinergyt2 {
 	struct work_struct query_work;
 
 	wait_queue_head_t poll_wq;
+	int pending_fe_events;
 
 	void *streambuf;
 	dma_addr_t streambuf_dmahandle;
@@ -663,6 +664,13 @@ int cinergyt2_ioctl (struct inode *inode
 		 *  are trivial to fill as soon FE_GET_FRONTEND is done.
 		 */
 		struct dvb_frontend_event *e = (void *) arg;
+		if (cinergyt2->pending_fe_events == 0) {
+			if (file->f_flags & O_NONBLOCK)
+				return -EWOULDBLOCK;
+			wait_event_interruptible(cinergyt2->poll_wq,
+						 cinergyt2->pending_fe_events > 0);
+		}
+		cinergyt2->pending_fe_events = 0;
 		return cinergyt2_ioctl(inode, file, FE_READ_STATUS,
 					(unsigned long) &e->status);
 	}
@@ -695,7 +703,7 @@ int cinergyt2_mmap(struct file *file, st
 		goto bailout;
 	}
 
-        vma->vm_flags |= (VM_IO | VM_DONTCOPY);
+	vma->vm_flags |= (VM_IO | VM_DONTCOPY);
 	vma->vm_file = file;
 
 	ret = remap_pfn_range(vma, vma->vm_start,
@@ -711,11 +719,11 @@ bailout:
 
 static
 struct file_operations cinergyt2_fops = {
-	.owner          = THIS_MODULE,
+	.owner		= THIS_MODULE,
 	.ioctl		= cinergyt2_ioctl,
-	.poll           = cinergyt2_poll,
-	.open           = cinergyt2_open,
-	.release        = cinergyt2_release,
+	.poll		= cinergyt2_poll,
+	.open		= cinergyt2_open,
+	.release	= cinergyt2_release,
 /*	.mmap		= cinergyt2_mmap*/
 };
 
@@ -800,8 +808,10 @@ static void cinergyt2_query (void *data)
 	unc += le32_to_cpu(s->uncorrected_block_count);
 	s->uncorrected_block_count = unc;
 
-	if (lock_bits != s->lock_bits)
+	if (lock_bits != s->lock_bits) {
 		wake_up_interruptible(&cinergyt2->poll_wq);
+		cinergyt2->pending_fe_events++;
+	}
 
 	schedule_delayed_work(&cinergyt2->query_work,
 			      msecs_to_jiffies(QUERY_INTERVAL));