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>

2 files changed, 29 insertions, 23 deletions

diff --git a/drivers/media/common/saa7146_core.c b/drivers/media/common/saa7146_core.c
index 12cda9eebd12..1c962a2b44df 100644
--- a/drivers/media/common/saa7146_core.c
+++ b/drivers/media/common/saa7146_core.c
@@ -248,10 +248,11 @@ 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 ) {
@@ -259,8 +260,6 @@ static irqreturn_t interrupt_hw(int irq, void *dev_id)
                 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;
 }
 
diff --git a/drivers/media/common/saa7146_i2c.c b/drivers/media/common/saa7146_i2c.c
index f823286341eb..7e7689afae62 100644
--- a/drivers/media/common/saa7146_i2c.c
+++ b/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"));
                 }