patch-2.2.17 linux/drivers/char/generic_serial.c

• Lines: 369
• Date: Mon Sep 4 18:39:17 2000
• Orig file: v2.2.16/drivers/char/generic_serial.c
• Orig date: Mon Sep 4 18:37:32 2000

diff -u --recursive --new-file v2.2.16/drivers/char/generic_serial.c linux/drivers/char/generic_serial.c
@@ -12,12 +12,18 @@
  *  Version 0.1 -- December, 1998. Initial version.
  *  Version 0.2 -- March, 1999.    Some more routines. Bugfixes. Etc.
  *  Version 0.5 -- August, 1999.   Some more fixes. Reformat for Linus.
- */
+ *
+ *  BitWizard is actively maintaining this file. We sometimes find
+ *  that someone submitted changes to this file. We really appreciate
+ *  your help, but please submit changes through us. We're doing our
+ *  best to be responsive.  -- REW
+ * */
 
 #include <linux/tty.h>
 #include <linux/serial.h>
 #include <linux/mm.h>
 #include <asm/semaphore.h>
+#include <asm/uaccess.h>
 #include <linux/version.h>
 #include <linux/module.h>
 #include <linux/compatmac.h>
@@ -40,8 +46,6 @@
 #define func_enter() gs_dprintk (GS_DEBUG_FLOW, "gs: enter " __FUNCTION__ "\n")
 #define func_exit()  gs_dprintk (GS_DEBUG_FLOW, "gs: exit  " __FUNCTION__ "\n")
 
-
-
 #if NEW_WRITE_LOCKING
 #define DECL      /* Nothing */
 #define LOCKIT    down (& port->port_write_sem);
@@ -52,6 +56,9 @@
 #define RELEASEIT restore_flags (flags)
 #endif
 
+#ifdef MODULE
+MODULE_PARM(gs_debug, "i");
+#endif
 
 #ifdef DEBUG
 static void my_hd (unsigned char *addr, int len)
@@ -77,10 +84,18 @@
 
 void gs_put_char(struct tty_struct * tty, unsigned char ch)
 {
-	struct gs_port *port = tty->driver_data;
+	struct gs_port *port;
 	DECL
 
-	/*  func_enter (); */
+	func_enter (); 
+
+	if (!tty) return;
+
+	port = tty->driver_data;
+
+	if (!port) return;
+
+	if (! (port->flags & ASYNC_INITIALIZED)) return;
 
 	/* Take a lock on the serial tranmit buffer! */
 	LOCKIT;
@@ -96,7 +111,7 @@
 	port->xmit_cnt++;  /* Characters in buffer */
 
 	RELEASEIT;
-	/* func_exit ();*/
+	func_exit ();
 }
 
 
@@ -112,11 +127,17 @@
 int gs_write(struct tty_struct * tty, int from_user, 
                     const unsigned char *buf, int count)
 {
-	struct gs_port *port = tty->driver_data;
+	struct gs_port *port;
 	int c, total = 0;
 	int t;
 
-	/* func_enter (); */
+	func_enter ();
+
+	if (!tty) return 0;
+
+	port = tty->driver;
+
+	if (!port) return 0;
 
 	if (! (port->flags & ASYNC_INITIALIZED))
 		return 0;
@@ -167,7 +188,7 @@
 		port->flags |= GS_TX_INTEN;
 		port->rd->enable_tx_interrupts (port);
 	}
-	/* func_exit (); */
+	func_exit ();
 	return total;
 }
 #else
@@ -210,12 +231,9 @@
 	if (!port || !port->xmit_buf || !tmp_buf)
 		return -EIO;
 
-	/* printk ("from_user = %d.\n", from_user); */
 	save_flags(flags);
 	if (from_user) {
-		/* printk ("Going into the semaphore\n"); */
 		down(&tmp_buf_sem);
-		/* printk ("got out of the semaphore\n"); */
 		while (1) {
 			c = count;
 
@@ -309,11 +327,11 @@
 	struct gs_port *port = tty->driver_data;
 	int ret;
 
-	/* func_enter (); */
+	func_enter ();
 	ret = SERIAL_XMIT_SIZE - port->xmit_cnt - 1;
 	if (ret < 0)
 		ret = 0;
-	/* func_exit (); */
+	func_exit ();
 	return ret;
 }
 
@@ -330,7 +348,7 @@
 
 int gs_real_chars_in_buffer(struct tty_struct *tty)
 {
-	struct gs_port *port = tty->driver_data;
+	struct gs_port *port;
 	func_enter ();
 
 	if (!tty) return 0;
@@ -361,22 +379,17 @@
 
 	if (!port || port->xmit_cnt < 0 || !port->xmit_buf) {
 		gs_dprintk (GS_DEBUG_FLUSH, "ERROR: !port, !port->xmit_buf or prot->xmit_cnt < 0.\n");
-	func_exit();
+		func_exit();
 		return -EINVAL;  /* This is an error which we don't know how to handle. */
 	}
-	gs_dprintk (GS_DEBUG_FLUSH, "checkpoint 1\n");
 
 	rcib = gs_real_chars_in_buffer(port->tty);
 
-	gs_dprintk (GS_DEBUG_FLUSH, "checkpoint 2\n");
-
 	if(rcib <= 0) {
 		gs_dprintk (GS_DEBUG_FLUSH, "nothing to wait for.\n");
 		func_exit();
 		return rv;
 	}
-	gs_dprintk (GS_DEBUG_FLUSH, "checkpoint 3\n");
-
 	/* stop trying: now + twice the time it would normally take +  seconds */
 	end_jiffies  = jiffies; 
 	if (timeout !=  MAX_SCHEDULE_TIMEOUT)
@@ -424,17 +437,23 @@
 
 void gs_flush_buffer(struct tty_struct *tty)
 {
-	struct gs_port *port = tty->driver_data;
+	struct gs_port *port;
 	unsigned long flags;
 
 	func_enter ();
+
+	if (!tty) return;
+
+	port = tty->driver_data;
+
+	if (!port) return;
+
 	/* XXX Would the write semaphore do? */
 	save_flags(flags); cli();
 	port->xmit_cnt = port->xmit_head = port->xmit_tail = 0;
 	restore_flags(flags);
 
 	wake_up_interruptible(&tty->write_wait);
-	wake_up_interruptible(&tty->poll_wait);
 	if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
 	    tty->ldisc.write_wakeup)
 		(tty->ldisc.write_wakeup)(tty);
@@ -444,9 +463,16 @@
 
 void gs_flush_chars(struct tty_struct * tty)
 {
-	struct gs_port *port = tty->driver_data;
+	struct gs_port *port;
 
 	func_enter ();
+
+	if (!tty) return;
+
+	port = tty->driver_data;
+
+	if (!port) return;
+
 	if (port->xmit_cnt <= 0 || tty->stopped || tty->hw_stopped ||
 	    !port->xmit_buf) {
 		func_exit ();
@@ -462,9 +488,16 @@
 
 void gs_stop(struct tty_struct * tty)
 {
-	struct gs_port *port = tty->driver_data;
+	struct gs_port *port;
 
 	func_enter ();
+
+	if (!tty) return;
+
+	port = tty->driver_data;
+
+	if (!port) return;
+
 	if (port->xmit_cnt && 
 	    port->xmit_buf && 
 	    (port->flags & GS_TX_INTEN) ) {
@@ -477,7 +510,13 @@
 
 void gs_start(struct tty_struct * tty)
 {
-	struct gs_port *port = tty->driver_data;
+	struct gs_port *port;
+
+	if (!tty) return;
+
+	port = tty->driver_data;
+
+	if (!port) return;
 
 	if (port->xmit_cnt && 
 	    port->xmit_buf && 
@@ -492,7 +531,11 @@
 void gs_shutdown_port (struct gs_port *port)
 {
 	long flags;
+
 	func_enter();
+	
+	if (!port) return;
+	
 	if (!(port->flags & ASYNC_INITIALIZED))
 		return;
 
@@ -517,10 +560,13 @@
 
 void gs_hangup(struct tty_struct *tty)
 {
-	struct gs_port   *port = tty->driver_data;
+	struct gs_port   *port;
 
 	func_enter ();
 
+	if (!tty) return;
+
+	port = tty->driver_data;
 	tty = port->tty;
 	if (!tty) return;
 
@@ -541,15 +587,19 @@
 	struct gs_port *port = private_;
 	struct tty_struct *tty;
 
+	func_enter ();
+
+	if (!port) return;
+
 	tty = port->tty;
-	if(!tty) return;
+
+	if (!tty) return;
 
 	if (test_and_clear_bit(RS_EVENT_WRITE_WAKEUP, &port->event)) {
 		if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
 		    tty->ldisc.write_wakeup)
 			(tty->ldisc.write_wakeup)(tty);
 		wake_up_interruptible(&tty->write_wait);
-		wake_up_interruptible(&tty->poll_wait);
 	}
 	func_exit ();
 }
@@ -565,8 +615,13 @@
 	struct tty_struct *tty;
 
 	func_enter ();
+
+	if (!port) return 0;
+
 	tty = port->tty;
 
+	if (!tty) return 0;
+
 	gs_dprintk (GS_DEBUG_BTR, "Entering block_till_ready.\n"); 
 	/*
 	 * If the device is in the middle of being closed, then block
@@ -625,8 +680,6 @@
 			do_clocal = 1;
 	}
 
-	gs_dprintk (GS_DEBUG_BTR, "after clocal check.\n"); 
-
 	/*
 	 * Block waiting for the carrier detect and the line to become
 	 * free (i.e., not in use by the callout).  While we are in
@@ -635,10 +688,10 @@
 	 * exit, either normal or abnormal.
 	 */
 	retval = 0;
+
 	add_wait_queue(&port->open_wait, &wait);
 
 	gs_dprintk (GS_DEBUG_BTR, "after add waitq.\n"); 
-
 	cli();
 	if (!tty_hung_up_p(filp))
 		port->count--;
@@ -690,15 +743,12 @@
 	struct gs_port *port;
 
 	func_enter ();
-	port = (struct gs_port *) tty->driver_data;
 
-	gs_dprintk (GS_DEBUG_CLOSE, "tty=%p, port=%p port->tty=%p\n",
-	            tty, port, port->tty);
+	if (!tty) return;
 
-	if(! port) {
-		func_exit();
-		return;
-	}
+	port = (struct gs_port *) tty->driver_data;
+
+	if (!port) return;
 
 	if (!port->tty) {
 		/* This seems to happen when this is called from vhangup. */
@@ -706,7 +756,6 @@
 		port->tty = tty;
 	}
 
-
 	save_flags(flags); cli();
 
 	if (tty_hung_up_p(filp)) {
@@ -800,14 +849,19 @@
 void gs_set_termios (struct tty_struct * tty, 
                      struct termios * old_termios)
 {
-	struct gs_port *port = tty->driver_data;
+	struct gs_port *port;
 	int baudrate, tmp, rv;
 	struct termios *tiosp;
 
 	func_enter();
 
-	tiosp = tty->termios;
+	if (!tty) return;
+
+	port = tty->driver_data;
 
+	if (!port) return;
+
+	tiosp = tty->termios;
 
 	if (gs_debug & GS_DEBUG_TERMIOS) {
 		gs_dprintk (GS_DEBUG_TERMIOS, "termios structure (%p):\n", tiosp);