X-Git-Url: http://git.rot13.org/?a=blobdiff_plain;f=drivers%2Fchar%2Ftty_ioctl.c;h=fd471cb3338fbd1d008c936f5d44cfe5691a952b;hb=3a2842480bbef42c3c90e14c1f378360d8c20a0c;hp=30486df9fd3f74d198b78aeb5c78c84f5d8e540c;hpb=606d099cdd1080bbb50ea50dc52d98252f8f10a1;p=powerpc.git

diff --git a/drivers/char/tty_ioctl.c b/drivers/char/tty_ioctl.c
index 30486df9fd..fd471cb333 100644
--- a/drivers/char/tty_ioctl.c
+++ b/drivers/char/tty_ioctl.c
@@ -225,7 +225,7 @@ EXPORT_SYMBOL(tty_termios_input_baud_rate);
 
 /**
  *	tty_termios_encode_baud_rate
- *	@termios: termios structure
+ *	@termios: ktermios structure holding user requested state
  *	@ispeed: input speed
  *	@ospeed: output speed
  *
@@ -233,7 +233,10 @@ EXPORT_SYMBOL(tty_termios_input_baud_rate);
  *	used as a library helper for drivers os that they can report back
  *	the actual speed selected when it differs from the speed requested
  *
- *	For now input and output speed must agree.
+ *	For maximal back compatibility with legacy SYS5/POSIX *nix behaviour
+ *	we need to carefully set the bits when the user does not get the
+ *	desired speed. We allow small margins and preserve as much of possible
+ *	of the input intent to keep compatiblity.
  *
  *	Locking: Caller should hold termios lock. This is already held
  *	when calling this function from the driver termios handler.
@@ -242,32 +245,44 @@ EXPORT_SYMBOL(tty_termios_input_baud_rate);
 void tty_termios_encode_baud_rate(struct ktermios *termios, speed_t ibaud, speed_t obaud)
 {
 	int i = 0;
-	int ifound = 0, ofound = 0;
+	int ifound = -1, ofound = -1;
+	int iclose = ibaud/50, oclose = obaud/50;
+	int ibinput = 0;
 
 	termios->c_ispeed = ibaud;
 	termios->c_ospeed = obaud;
 
+	/* If the user asked for a precise weird speed give a precise weird
+	   answer. If they asked for a Bfoo speed they many have problems
+	   digesting non-exact replies so fuzz a bit */
+
+	if ((termios->c_cflag & CBAUD) == BOTHER)
+		oclose = 0;
+	if (((termios->c_cflag >> IBSHIFT) & CBAUD) == BOTHER)
+		iclose = 0;
+	if ((termios->c_cflag >> IBSHIFT) & CBAUD)
+		ibinput = 1;	/* An input speed was specified */
+
 	termios->c_cflag &= ~CBAUD;
-	/* Identical speed means no input encoding (ie B0 << IBSHIFT)*/
-	if (termios->c_ispeed == termios->c_ospeed)
-		ifound = 1;
 
 	do {
-		if (obaud == baud_table[i]) {
+		if (obaud - oclose >= baud_table[i] && obaud + oclose <= baud_table[i]) {
 			termios->c_cflag |= baud_bits[i];
-			ofound = 1;
-			/* So that if ibaud == obaud we don't set it */
-			continue;
+			ofound = i;
 		}
-		if (ibaud == baud_table[i]) {
-			termios->c_cflag |= (baud_bits[i] << IBSHIFT);
-			ifound = 1;
+		if (ibaud - iclose >= baud_table[i] && ibaud + iclose <= baud_table[i]) {
+			/* For the case input == output don't set IBAUD bits if the user didn't do so */
+			if (ofound != i || ibinput)
+				termios->c_cflag |= (baud_bits[i] << IBSHIFT);
+			ifound = i;
 		}
 	}
 	while(++i < n_baud_table);
-	if (!ofound)
+	if (ofound == -1)
 		termios->c_cflag |= BOTHER;
-	if (!ifound)
+	/* Set exact input bits only if the input and output differ or the
+	   user already did */
+	if (ifound == -1 && (ibaud != obaud  || ibinput))
 		termios->c_cflag |= (BOTHER << IBSHIFT);
 }
 
@@ -399,23 +414,27 @@ static int set_termios(struct tty_struct * tty, void __user *arg, int opt)
 	if (retval)
 		return retval;
 
+	memcpy(&tmp_termios, tty->termios, sizeof(struct ktermios));
+
 	if (opt & TERMIOS_TERMIO) {
-		memcpy(&tmp_termios, tty->termios, sizeof(struct ktermios));
 		if (user_termio_to_kernel_termios(&tmp_termios,
 						(struct termio __user *)arg))
 			return -EFAULT;
 #ifdef TCGETS2
 	} else if (opt & TERMIOS_OLD) {
-		memcpy(&tmp_termios, tty->termios, sizeof(struct termios));
 		if (user_termios_to_kernel_termios_1(&tmp_termios,
-						(struct termios_v1 __user *)arg))
+						(struct termios __user *)arg))
 			return -EFAULT;
-#endif
 	} else {
 		if (user_termios_to_kernel_termios(&tmp_termios,
-						(struct termios __user *)arg))
+						(struct termios2 __user *)arg))
 			return -EFAULT;
 	}
+#else
+	} else if (user_termios_to_kernel_termios(&tmp_termios,
+					(struct termios __user *)arg))
+		return -EFAULT;
+#endif
 
 	/* If old style Bfoo values are used then load c_ispeed/c_ospeed with the real speed
 	   so its unconditionally usable */
@@ -707,11 +726,11 @@ int n_tty_ioctl(struct tty_struct * tty, struct file * file,
 			return 0;
 #else
 		case TCGETS:
-			if (kernel_termios_to_user_termios_1((struct termios_v1 __user *)arg, real_tty->termios))
+			if (kernel_termios_to_user_termios_1((struct termios __user *)arg, real_tty->termios))
 				return -EFAULT;
 			return 0;
 		case TCGETS2:
-			if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios))
+			if (kernel_termios_to_user_termios((struct termios2 __user *)arg, real_tty->termios))
 				return -EFAULT;
 			return 0;
 		case TCSETSF2: