From 2a90697834652eca63b0603d4effc361af346b9d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Robert=20J=C3=B6rdens?= <rj@quartiq.de>
Date: Wed, 4 Aug 2021 10:50:39 +0000
Subject: [PATCH] qspi: expand padding comments

---
 ad9959/src/lib.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/ad9959/src/lib.rs b/ad9959/src/lib.rs
index 4c99732..8e691e0 100644
--- a/ad9959/src/lib.rs
+++ b/ad9959/src/lib.rs
@@ -602,10 +602,14 @@ impl ProfileSerializer {
     #[inline]
     fn pad(&mut self) {
         // Pad the buffer to 32-bit (4 byte) alignment by adding dummy writes to CSR and LSRR.
+        // In the case of 1 byte padding, this instead pads with 5 bytes as there is no
+        // valid single-byte write that could be used.
         if self.index & 1 != 0 {
+            // Pad with 3 bytes
             self.add_write(Register::LSRR, &[0, 0]);
         }
         if self.index & 2 != 0 {
+            // Pad with 2 bytes
             self.add_write(Register::CSR, &[(self.mode as u8) << 1]);
         }
         debug_assert_eq!(self.index & 3, 0);