From b05315ade7bfe7d7ec52433d769aa0cda5148bb5 Mon Sep 17 00:00:00 2001
From: Frank Mori Hess <fmhess@speakeasy.net>
Date: Sat, 17 Jul 2004 22:55:05 +0000
Subject: [PATCH] list 10 insn limit on insn lists

---
 comedi/comedi_fops.c  | 8 ++------
 include/linux/sched.h | 7 +++++++
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/comedi/comedi_fops.c b/comedi/comedi_fops.c
index 84139125..79fec01a 100644
--- a/comedi/comedi_fops.c
+++ b/comedi/comedi_fops.c
@@ -552,7 +552,6 @@ static int parse_insn(comedi_device *dev,comedi_insn *insn,lsampl_t *data,void *
  */
 /* arbitrary limits */
 #define MAX_SAMPLES 256
-#define MAX_INSNS 10
 static int do_insnlist_ioctl(comedi_device *dev,void *arg,void *file)
 {
 	comedi_insnlist insnlist;
@@ -564,11 +563,6 @@ static int do_insnlist_ioctl(comedi_device *dev,void *arg,void *file)
 	if(copy_from_user(&insnlist,arg,sizeof(comedi_insnlist)))
 		return -EFAULT;
 
-	if(insnlist.n_insns>=MAX_INSNS){
-		DPRINTK("insnlist too long\n");
-		return -EINVAL;
-	}
-
 	data=kmalloc(sizeof(lsampl_t)*MAX_SAMPLES,GFP_KERNEL);
 	if(!data){
 		DPRINTK("kmalloc failed\n");
@@ -618,6 +612,8 @@ static int do_insnlist_ioctl(comedi_device *dev,void *arg,void *file)
 				goto error;
 			}
 		}
+		if(need_resched())
+			schedule();
 	}
 
 error:
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 753d54f7..5e040ddc 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -11,6 +11,13 @@
 #define signal_pending(x)	(((x)->signal) & (~(x)->blocked))
 #endif
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,4,20) /* not sure exactly when need_resched() was added */
+static inline int need_resched(void)
+{
+	return current->need_resched;
+}
+#endif
+
 #include_next <linux/sched.h>
 
 #endif
-- 
2.26.2