diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c
index f5f5a9706fcc..4cb27dc542ce 100644
--- a/drivers/firewire/core-cdev.c
+++ b/drivers/firewire/core-cdev.c
@@ -51,7 +51,7 @@
 /*
  * ABI version history is documented in linux/firewire-cdev.h.
  */
-#define FW_CDEV_KERNEL_VERSION			4
+#define FW_CDEV_KERNEL_VERSION			5
 #define FW_CDEV_VERSION_EVENT_REQUEST2		4
 #define FW_CDEV_VERSION_ALLOCATE_REGION_END	4
 
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 07d3c8d58b30..632562667a01 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -2689,7 +2689,7 @@ static void copy_iso_headers(struct iso_context *ctx, const u32 *dma_hdr)
 	u32 *ctx_hdr;
 
 	if (ctx->header_length + ctx->base.header_size > PAGE_SIZE)
-		return;
+		flush_iso_completions(ctx);
 
 	ctx_hdr = ctx->header + ctx->header_length;
 	ctx->last_timestamp = (u16)le32_to_cpu((__force __le32)dma_hdr[0]);
@@ -2826,16 +2826,16 @@ static int handle_it_packet(struct context *context,
 
 	sync_it_packet_for_cpu(context, d);
 
-	if (ctx->header_length + 4 < PAGE_SIZE) {
-		ctx_hdr = ctx->header + ctx->header_length;
-		/* Present this value as big-endian to match the receive code */
-		*ctx_hdr = cpu_to_be32(
-				((u32)le16_to_cpu(pd->transfer_status) << 16) |
-				le16_to_cpu(pd->res_count));
-		ctx->header_length += 4;
-	}
+	if (ctx->header_length + 4 > PAGE_SIZE)
+		flush_iso_completions(ctx);
 
+	ctx_hdr = ctx->header + ctx->header_length;
 	ctx->last_timestamp = le16_to_cpu(last->res_count);
+	/* Present this value as big-endian to match the receive code */
+	*ctx_hdr = cpu_to_be32((le16_to_cpu(pd->transfer_status) << 16) |
+			       le16_to_cpu(pd->res_count));
+	ctx->header_length += 4;
+
 	if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS))
 		flush_iso_completions(ctx);
 
diff --git a/include/linux/firewire-cdev.h b/include/linux/firewire-cdev.h
index cc1b570a2eb3..b9bd349c6930 100644
--- a/include/linux/firewire-cdev.h
+++ b/include/linux/firewire-cdev.h
@@ -207,12 +207,15 @@ struct fw_cdev_event_request2 {
  * @closure:	See &fw_cdev_event_common;
  *		set by %FW_CDEV_CREATE_ISO_CONTEXT ioctl
  * @type:	See &fw_cdev_event_common; always %FW_CDEV_EVENT_ISO_INTERRUPT
- * @cycle:	Cycle counter of the interrupt packet
+ * @cycle:	Cycle counter of the last completed packet
  * @header_length: Total length of following headers, in bytes
  * @header:	Stripped headers, if any
  *
  * This event is sent when the controller has completed an &fw_cdev_iso_packet
- * with the %FW_CDEV_ISO_INTERRUPT bit set.
+ * with the %FW_CDEV_ISO_INTERRUPT bit set, or when there have been so many
+ * completed packets without the interrupt bit set that the kernel's internal
+ * buffer for @header is about to overflow.  (In the latter case, kernels with
+ * ABI version < 5 drop header data up to the next interrupt packet.)
  *
  * Isochronous transmit events (context type %FW_CDEV_ISO_CONTEXT_TRANSMIT):
  *
@@ -440,6 +443,8 @@ union fw_cdev_event {
  *               - added %FW_CDEV_EVENT_ISO_INTERRUPT_MULTICHANNEL,
  *                 %FW_CDEV_ISO_CONTEXT_RECEIVE_MULTICHANNEL, and
  *                 %FW_CDEV_IOC_SET_ISO_CHANNELS
+ *  5  (3.4)     - send %FW_CDEV_EVENT_ISO_INTERRUPT events when needed to
+ *                 avoid dropping data
  */
 
 /**