[PATCH] ppc32: remove cli()/sti() in arch/ppc/8xx_io/cs4218_tdm.c

Replace save_flags()/resore_flags() with
spin_lock_irqsave()/spin_unlock_irqrestore() and document reasons for locking.
Signed-off-by: James Nelson <james4765@gmail.com>
Signed-off-by: Tom Rini <trini@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/ppc/8xx_io/cs4218_tdm.c

@@ -55,6 +55,8 @@ static int irq_installed = 0;
 static char **sound_buffers = NULL;
 static char **sound_read_buffers = NULL;
 
+static spinlock_t cs4218_lock = SPIN_LOCK_UNLOCKED;
+
 /* Local copies of things we put in the control register.  Output
  * volume, like most codecs is really attenuation.
  */
@@ -1206,7 +1208,8 @@ static void CS_Play(void)
 	volatile cbd_t	*bdp;
 	volatile cpm8xx_t *cp;
 
-	save_flags(flags); cli();
+	/* Protect buffer */
+	spin_lock_irqsave(&cs4218_lock, flags);
 #if 0
 	if (awacs_beep_state) {
 		/* sound takes precedence over beeps */
@@ -1263,7 +1266,7 @@ static void CS_Play(void)
 
 		++sq.active;
 	}
-	restore_flags(flags);
+	spin_unlock_irqrestore(&cs4218_lock, flags);
 }
 
 
@@ -1275,7 +1278,8 @@ static void CS_Record(void)
 	if (read_sq.active)
 		return;
 
-	save_flags(flags); cli();
+	/* Protect buffer */
+	spin_lock_irqsave(&cs4218_lock, flags);
 
 	/* This is all we have to do......Just start it up.
 	*/
@@ -1284,7 +1288,7 @@ static void CS_Record(void)
 
 	read_sq.active = 1;
 
-        restore_flags(flags);
+        spin_unlock_irqrestore(&cs4218_lock, flags);
 }
 
 
@@ -1365,14 +1369,15 @@ static void cs_nosound(unsigned long xx)
 {
 	unsigned long flags;
 
-	save_flags(flags); cli();
+	/* not sure if this is needed, since hardware command is #if 0'd */
+	spin_lock_irqsave(&cs4218_lock, flags);
 	if (beep_playing) {
 #if 0
 		st_le16(&beep_dbdma_cmd->command, DBDMA_STOP);
 #endif
 		beep_playing = 0;
 	}
-	restore_flags(flags);
+	spin_unlock_irqrestore(&cs4218_lock, flags);
 }
 
 static struct timer_list beep_timer = TIMER_INITIALIZER(cs_nosound, 0, 0);
@@ -1401,21 +1406,22 @@ static void cs_mksound(unsigned int hz, unsigned int ticks)
 		return;
 #endif
 	}
-	save_flags(flags); cli();
+	/* lock while modifying beep_timer */
+	spin_lock_irqsave(&cs4218_lock, flags);
 	del_timer(&beep_timer);
 	if (ticks) {
 		beep_timer.expires = jiffies + ticks;
 		add_timer(&beep_timer);
 	}
 	if (beep_playing || sq.active || beep_buf == NULL) {
-		restore_flags(flags);
+		spin_unlock_irqrestore(&cs4218_lock, flags);
 		return;		/* too hard, sorry :-( */
 	}
 	beep_playing = 1;
 #if 0
 	st_le16(&beep_dbdma_cmd->command, OUTPUT_MORE + BR_ALWAYS);
 #endif
-	restore_flags(flags);
+	spin_unlock_irqrestore(&cs4218_lock, flags);
 
 	if (hz == beep_hz_cache && beep_volume == beep_volume_cache) {
 		nsamples = beep_nsamples_cache;
@@ -1442,7 +1448,7 @@ static void cs_mksound(unsigned int hz, unsigned int ticks)
 	st_le32(&beep_dbdma_cmd->phy_addr, virt_to_bus(beep_buf));
 	awacs_beep_state = 1;
 
-	save_flags(flags); cli();
+	spin_lock_irqsave(&cs4218_lock, flags);
 	if (beep_playing) {	/* i.e. haven't been terminated already */
 		out_le32(&awacs_txdma->control, (RUN|WAKE|FLUSH|PAUSE) << 16);
 		out_le32(&awacs->control,
@@ -1452,8 +1458,8 @@ static void cs_mksound(unsigned int hz, unsigned int ticks)
 		out_le32(&awacs_txdma->cmdptr, virt_to_bus(beep_dbdma_cmd));
 		out_le32(&awacs_txdma->control, RUN | (RUN << 16));
 	}
+	spin_unlock_irqrestore(&cs4218_lock, flags);
 #endif
-	restore_flags(flags);
 }
 
 static MACHINE mach_cs4218 = {