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>

drivers/media/common/saa7146_core.c

@@ -248,19 +248,18 @@ int saa7146_pgtable_build_single(struct pci_dev *pci, struct saa7146_pgtable *pt
 static irqreturn_t interrupt_hw(int irq, void *dev_id)
 {
 	struct saa7146_dev *dev = dev_id;
-	u32 isr = 0;
+	u32 isr;
+	u32 ack_isr;
 
 	/* read out the interrupt status register */
-	isr = saa7146_read(dev, ISR);
+	ack_isr = isr = saa7146_read(dev, ISR);
 
 	/* is this our interrupt? */
 	if ( 0 == isr ) {
 		/* nope, some other device */
 		return IRQ_NONE;
 	}
 
-	saa7146_write(dev, ISR, isr);
-
 	if( 0 != (dev->ext)) {
 		if( 0 != (dev->ext->irq_mask & isr )) {
 			if( 0 != dev->ext->irq_func ) {
@@ -283,21 +282,16 @@ static irqreturn_t interrupt_hw(int irq, void *dev_id)
 		isr &= ~MASK_28;
 	}
 	if (0 != (isr & (MASK_16|MASK_17))) {
-		u32 status = saa7146_read(dev, I2C_STATUS);
-		if( (0x3 == (status & 0x3)) || (0 == (status & 0x1)) ) {
-			SAA7146_IER_DISABLE(dev, MASK_16|MASK_17);
-			/* only wake up if we expect something */
-			if( 0 != dev->i2c_op ) {
-				u32 psr = (saa7146_read(dev, PSR) >> 16) & 0x2;
-				u32 ssr = (saa7146_read(dev, SSR) >> 17) & 0x1f;
-				DEB_I2C(("irq: i2c, status: 0x%08x, psr:0x%02x, ssr:0x%02x).\n",status,psr,ssr));
-				dev->i2c_op = 0;
-				wake_up(&dev->i2c_wq);
-			} else {
-				DEB_I2C(("unexpected irq: i2c, status: 0x%08x, isr %#x\n",status, isr));
-			}
+		SAA7146_IER_DISABLE(dev, MASK_16|MASK_17);
+		/* only wake up if we expect something */
+		if (0 != dev->i2c_op) {
+			dev->i2c_op = 0;
+			wake_up(&dev->i2c_wq);
 		} else {
-			DEB_I2C(("unhandled irq: i2c, status: 0x%08x, isr %#x\n",status, isr));
+			u32 psr = saa7146_read(dev, PSR);
+			u32 ssr = saa7146_read(dev, SSR);
+			printk(KERN_WARNING "%s: unexpected i2c irq: isr %08x psr %08x ssr %08x\n",
+			       dev->name, isr, psr, ssr);
 		}
 		isr &= ~(MASK_16|MASK_17);
 	}
@@ -306,6 +300,7 @@ static irqreturn_t interrupt_hw(int irq, void *dev_id)
 		ERR(("disabling interrupt source(s)!\n"));
 		SAA7146_IER_DISABLE(dev,isr);
 	}
+	saa7146_write(dev, ISR, ack_isr);
 	return IRQ_HANDLED;
 }
 

drivers/media/common/saa7146_i2c.c

@@ -202,7 +202,8 @@ static int saa7146_i2c_writeout(struct saa7146_dev *dev, u32* dword, int short_d
 				/* 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 @@ static int saa7146_i2c_writeout(struct saa7146_dev *dev, u32* dword, int short_d
 				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 @@ static int saa7146_i2c_writeout(struct saa7146_dev *dev, u32* dword, int short_d
 				/* 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 @@ static int saa7146_i2c_writeout(struct saa7146_dev *dev, u32* dword, int short_d
 	}
 
 	/* 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"));
 		}