svn commit: r192113 - head/lib/libbluetooth

[Maksim Yevmenkin]

Author: emax
Date: Thu May 14 17:10:19 2009
New Revision: 192113
URL: http://svn.freebsd.org/changeset/base/192113

Log:
  Avoid floating point arithmetic while calculating iquiry length.
  
  Submitted by:	Iain Hibbert < plunky -at- rya-online -dot- net >
  MFC after:	1 week

Modified:
  head/lib/libbluetooth/hci.c

Modified: head/lib/libbluetooth/hci.c
==============================================================================
--- head/lib/libbluetooth/hci.c	Thu May 14 17:04:58 2009	(r192112)
+++ head/lib/libbluetooth/hci.c	Thu May 14 17:10:19 2009	(r192113)
@@ -410,7 +410,6 @@ bt_devinquiry(char const *devname, time_
 	ng_hci_inquiry_response		*ir;
 	struct bt_devinquiry		*i;
 	int				s, n;
-	time_t				to;
 
 	if (ii == NULL) {
 		errno = EINVAL;
@@ -452,16 +451,20 @@ bt_devinquiry(char const *devname, time_
 	cp->lap[1] = 0x8b;
 	cp->lap[2] = 0x9e;
 
-	/* Calculate inquire length in 1.28 second units */
-	to = (time_t) ((double) length / 1.28);
-	if (to <= 0)
-		cp->inquiry_length = 4;		/* 5.12 seconds */
-	else if (to > 254)
-		cp->inquiry_length = 255;	/* 326.40 seconds */
-	else
-		cp->inquiry_length = to + 1;
+	/*
+	 * Calculate inquire length in 1.28 second units
+	 * v2.x specification says that 1.28 -> 61.44 seconds
+	 * range is acceptable
+	 */
+
+	if (length <= 0)
+		length = 5;
+	else if (length == 1)
+		length = 2;
+	else if (length > 62)
+		length = 62;
 
-	to = (time_t)((double) cp->inquiry_length * 1.28) + 1;
+	cp->inquiry_length = (uint8_t)((length * 100) / 128);
 
 	if (num_rsp <= 0 || num_rsp > 255)
 		num_rsp = 8;
@@ -484,7 +487,7 @@ bt_devinquiry(char const *devname, time_
 
 wait_for_more:
 
-	n = bt_devrecv(s, buf, sizeof(buf), to);
+	n = bt_devrecv(s, buf, sizeof(buf), length);
 	if (n < 0) {
 		free(i);
 		bt_devclose(s);