Merge branch 'fixes' into for-linus

[firefly-linux-kernel-4.4.55.git] / include / linux / firewire.h

diff --git a/include/linux/firewire.h b/include/linux/firewire.h
index db04ec5121cb770d6c571a59234997c60527e539..191501afd7fb040268496ea68a9e47e043bc906b 100644 (file)
--- a/include/linux/firewire.h
+++ b/include/linux/firewire.h
@@ -265,8 +265,16 @@ typedef void (*fw_transaction_callback_t)(struct fw_card *card, int rcode,
                                          void *data, size_t length,
                                          void *callback_data);
 /*
- * Important note:  Except for the FCP registers, the callback must guarantee
- * that either fw_send_response() or kfree() is called on the @request.
+ * This callback handles an inbound request subaction.  It is called in
+ * RCU read-side context, therefore must not sleep.
+ *
+ * The callback should not initiate outbound request subactions directly.
+ * Otherwise there is a danger of recursion of inbound and outbound
+ * transactions from and to the local node.
+ *
+ * The callback is responsible that either fw_send_response() or kfree()
+ * is called on the @request, except for FCP registers for which the core
+ * takes care of that.
  */
 typedef void (*fw_address_callback_t)(struct fw_card *card,
                                      struct fw_request *request,