V4L/DVB (5987): saa7146: clean-up irq processing

Interrupt processing fixed: First handle interrupt, then acknowledge it.
Otherwise the same interrupt might occur twice.
Cleaned-up i2c interrupt handler and i2c error messages.

Signed-off-by: Oliver Endriss <o.endriss@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/common/saa7146_i2c.c b/drivers/media/common/saa7146_i2c.c
index f823286..7e7689a 100644
--- a/drivers/media/common/saa7146_i2c.c
+++ b/drivers/media/common/saa7146_i2c.c
@@ -202,7 +202,8 @@
 				/* a signal arrived */
 				return -ERESTARTSYS;
 
-			printk(KERN_WARNING "saa7146_i2c_writeout: timed out waiting for end of xfer\n");
+			printk(KERN_WARNING "%s %s [irq]: timed out waiting for end of xfer\n",
+				dev->name, __FUNCTION__);
 			return -EIO;
 		}
 		status = saa7146_read(dev, I2C_STATUS);
@@ -219,7 +220,8 @@
 				break;
 			}
 			if (time_after(jiffies,timeout)) {
-				printk(KERN_WARNING "saa7146_i2c_writeout: timed out waiting for MC2\n");
+				printk(KERN_WARNING "%s %s: timed out waiting for MC2\n",
+					dev->name, __FUNCTION__);
 				return -EIO;
 			}
 		}
@@ -235,7 +237,8 @@
 				/* this is normal when probing the bus
 				 * (no answer from nonexisistant device...)
 				 */
-				DEB_I2C(("saa7146_i2c_writeout: timed out waiting for end of xfer\n"));
+				printk(KERN_WARNING "%s %s [poll]: timed out waiting for end of xfer\n",
+					dev->name, __FUNCTION__);
 				return -EIO;
 			}
 			if (++trial < 50 && short_delay)
@@ -246,8 +249,16 @@
 	}
 
 	/* give a detailed status report */
-	if ( 0 != (status & SAA7146_I2C_ERR)) {
+	if ( 0 != (status & (SAA7146_I2C_SPERR | SAA7146_I2C_APERR |
+			     SAA7146_I2C_DTERR | SAA7146_I2C_DRERR |
+			     SAA7146_I2C_AL    | SAA7146_I2C_ERR   |
+			     SAA7146_I2C_BUSY)) ) {
 
+		if ( 0 == (status & SAA7146_I2C_ERR) ||
+		     0 == (status & SAA7146_I2C_BUSY) ) {
+			/* it may take some time until ERR goes high - ignore */
+			DEB_I2C(("unexpected i2c status %04x\n", status));
+		}
 		if( 0 != (status & SAA7146_I2C_SPERR) ) {
 			DEB_I2C(("error due to invalid start/stop condition.\n"));
 		}