USB opt soft_unbid was added as of 2.6.27.

--- a/drivers/net/wireless/p54/p54usb.c
+++ b/drivers/net/wireless/p54/p54usb.c
@@ -1080,7 +1080,9 @@ static struct usb_driver p54u_driver = {
 	.resume = p54u_resume,
 	.reset_resume = p54u_resume,
 #endif /* CONFIG_PM */
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,27))
 	.soft_unbind = 1,
+#endif
 };
 
 static int __init p54u_init(void)
--- a/drivers/net/wireless/ath/ath9k/hif_usb.c
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.c
@@ -1311,7 +1311,9 @@ static struct usb_driver ath9k_hif_usb_d
 	.reset_resume = ath9k_hif_usb_resume,
 #endif
 	.id_table = ath9k_hif_usb_ids,
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,27))
 	.soft_unbind = 1,
+#endif
 };
 
 int ath9k_hif_usb_init(void)