4 files changed, 20 insertions, 0 deletions

diff --git a/drivers/media/video/cx18/cx18-firmware.c b/drivers/media/video/cx18/cx18-firmware.c
index ab02da727519..06f5563d6d5a 100644
--- a/drivers/media/video/cx18/cx18-firmware.c
+++ b/drivers/media/video/cx18/cx18-firmware.c
@@ -380,6 +380,17 @@ int cx18_firmware_init(struct cx18 *cx)
                 if (sz <= 0)
                         return -EIO;
         }
+
+        /*
+         * The CPU firmware apparently sets up to receive an interrupt for it's
+         * outgoing IRQ_CPU_TO_EPU_ACK to us (*boggle*).  We get an interrupt
+         * when it sends us an ack, but by the time we process it, that flag in
+         * the SW2 status register has been cleared by the CPU firmware.
+         * We'll prevent that not so useful behavior by clearing the CPU's
+         * interrupt enables for Ack IRQ's we want to process.
+         */
+        cx18_sw2_irq_disable_cpu(cx, IRQ_CPU_TO_EPU_ACK | IRQ_APU_TO_EPU_ACK);
+
         /* initialize GPIO */
         cx18_write_reg_expect(cx, 0x14001400, 0xc78110, 0x00001400, 0x14001400);
         return 0;
diff --git a/drivers/media/video/cx18/cx18-io.c b/drivers/media/video/cx18/cx18-io.c
index 48a8adc83c2f..3c6485fceea0 100644
--- a/drivers/media/video/cx18/cx18-io.c
+++ b/drivers/media/video/cx18/cx18-io.c
@@ -262,6 +262,13 @@ void cx18_sw2_irq_disable(struct cx18 *cx, u32 val)
         cx18_write_reg(cx, r & ~val, SW2_INT_ENABLE_PCI);
 }
 
+void cx18_sw2_irq_disable_cpu(struct cx18 *cx, u32 val)
+{
+        u32 r;
+        r = cx18_read_reg(cx, SW2_INT_ENABLE_CPU);
+        cx18_write_reg(cx, r & ~val, SW2_INT_ENABLE_CPU);
+}
+
 void cx18_setup_page(struct cx18 *cx, u32 addr)
 {
         u32 val;
diff --git a/drivers/media/video/cx18/cx18-io.h b/drivers/media/video/cx18/cx18-io.h
index cb695a59670d..4486b73faf5b 100644
--- a/drivers/media/video/cx18/cx18-io.h
+++ b/drivers/media/video/cx18/cx18-io.h
@@ -390,6 +390,7 @@ void cx18_sw1_irq_enable(struct cx18 *cx, u32 val);
 void cx18_sw1_irq_disable(struct cx18 *cx, u32 val);
 void cx18_sw2_irq_enable(struct cx18 *cx, u32 val);
 void cx18_sw2_irq_disable(struct cx18 *cx, u32 val);
+void cx18_sw2_irq_disable_cpu(struct cx18 *cx, u32 val);
 void cx18_setup_page(struct cx18 *cx, u32 addr);
 
 #endif /* CX18_IO_H */
diff --git a/drivers/media/video/cx18/cx18-irq.h b/drivers/media/video/cx18/cx18-irq.h
index 6173ca3bc9e4..6f3ec8963762 100644
--- a/drivers/media/video/cx18/cx18-irq.h
+++ b/drivers/media/video/cx18/cx18-irq.h
@@ -28,6 +28,7 @@
 #define SW1_INT_ENABLE_PCI              0xc7311c
 #define SW2_INT_SET                     0xc73140
 #define SW2_INT_STATUS                  0xc73144
+#define SW2_INT_ENABLE_CPU              0xc73158
 #define SW2_INT_ENABLE_PCI              0xc7315c
 
 irqreturn_t cx18_irq_handler(int irq, void *dev_id);