V4L/DVB (4914): Saa7146: Protect access to the IER register by a spinlock

Protect the access to the IER register of the SAA7146 by the device
spinlock. I2C transfers may use interrupt mode now.

Signed-off-by: Oliver Endriss <o.endriss@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 14 insertions, 4 deletions

diff --git a/include/media/saa7146.h b/include/media/saa7146.h
index fee579f10b32..afa5ff6469b3 100644
--- a/include/media/saa7146.h
+++ b/include/media/saa7146.h
@@ -42,10 +42,20 @@ extern unsigned int saa7146_debug;
 #define DEB_INT(x)  if (0!=(DEBUG_VARIABLE&0x20)) { DEBUG_PROLOG; printk x; } /* interrupt debug messages */
 #define DEB_CAP(x)  if (0!=(DEBUG_VARIABLE&0x40)) { DEBUG_PROLOG; printk x; } /* capture debug messages */
 
-#define SAA7146_IER_DISABLE(x,y) \
-        saa7146_write(x, IER, saa7146_read(x, IER) & ~(y));
-#define SAA7146_IER_ENABLE(x,y) \
-        saa7146_write(x, IER, saa7146_read(x, IER) | (y));
+#define SAA7146_IER_DISABLE(x,y)                                        \
+        do {                                                            \
+                unsigned int flags;                                     \
+                spin_lock_irqsave(&x->int_slock, flags);                \
+                saa7146_write(x, IER, saa7146_read(x, IER) & ~(y));     \
+                spin_unlock_irqrestore(&x->int_slock, flags);           \
+        } while(0)
+#define SAA7146_IER_ENABLE(x,y)                                         \
+        do {                                                            \
+                unsigned int flags;                                     \
+                spin_lock_irqsave(&x->int_slock, flags);                \
+                saa7146_write(x, IER, saa7146_read(x, IER) | (y));      \
+                spin_unlock_irqrestore(&x->int_slock, flags);           \
+        } while(0)
 #define SAA7146_ISR_CLEAR(x,y) \
         saa7146_write(x, ISR, (y));