Implement terminating the worker thread when the driver is about to

be deregistered.

Not yet tested, since by now, GEOM doesn't want us to deregister.  PHK
wants to fix that RSN.

2 files changed, 23 insertions, 3 deletions

diff --git a/sys/dev/fdc/fdc.c b/sys/dev/fdc/fdc.c
index 139285c..6df202c 100644
--- a/sys/dev/fdc/fdc.c
+++ b/sys/dev/fdc/fdc.c
@@ -761,8 +761,17 @@ fdc_worker(struct fdc_data *fdc)
 			if (fdc->bp == NULL)
 				msleep(&fdc->head, &fdc->fdc_mtx,
 				    PRIBIO, "-", hz);
-		} while (fdc->bp == NULL);
+		} while (fdc->bp == NULL &&
+		    (fdc->flags & FDC_KTHREAD_EXIT) == 0);
 		mtx_unlock(&fdc->fdc_mtx);
+
+		if (fdc->bp == NULL)
+			/*
+			 * Nothing to do, worker thread has been
+			 * requested to stop.
+			 */
+			return (0);
+
 		bp = fdc->bp;
 		fd = fdc->fd = bp->bio_driver1;
 		fdc->retry = 0;
@@ -1118,7 +1127,8 @@ fdc_thread(void *arg)
 	fdc = arg;
 	int i;
 
-	for (;;) {
+	fdc->flags |= FDC_KTHREAD_ALIVE;
+	while ((fdc->flags & FDC_KTHREAD_EXIT) == 0) {
 		i = fdc_worker(fdc);
 		if (i && debugflags & 0x20) {
 			if (fdc->bp != NULL) {
@@ -1129,6 +1139,8 @@ fdc_thread(void *arg)
 		}
 		fdc->retry += i;
 	}
+	fdc->flags &= ~(FDC_KTHREAD_EXIT | FDC_KTHREAD_ALIVE);
+	wakeup(&fdc->fdc_thread);
 }
 
 /*
@@ -1624,7 +1636,13 @@ fdc_detach(device_t dev)
 	if ((error = bus_generic_detach(dev)))
 		return (error);
 
-	/* XXX: kill thread */
+	/* kill worker thread */
+	fdc->flags |= FDC_KTHREAD_EXIT;
+	mtx_lock(&fdc->fdc_mtx);
+	while ((fdc->flags & FDC_KTHREAD_ALIVE) != 0)
+		msleep(&fdc->fdc_thread, &fdc->fdc_mtx, PRIBIO, "fdcdet", 0);
+	mtx_unlock(&fdc->fdc_mtx);
+
 	/* reset controller, turn motor off */
 	fdout_wr(fdc, 0);
 
diff --git a/sys/dev/fdc/fdcvar.h b/sys/dev/fdc/fdcvar.h
index 5ecf912..acba77e 100644
--- a/sys/dev/fdc/fdcvar.h
+++ b/sys/dev/fdc/fdcvar.h
@@ -46,6 +46,8 @@ struct fdc_data {
 #define FDC_HAS_FIFO	0x10
 #define FDC_NEEDS_RESET	0x20
 #define FDC_NODMA	0x40
+#define FDC_KTHREAD_EXIT	0x1000 /* request worker thread to stop */
+#define FDC_KTHREAD_ALIVE	0x2000 /* worker thread is alive */
 	struct	fd_data *fd;	/* The active drive */
 	int	retry;
 	int	fdout;		/* mirror of the w/o digital output reg */