From 79dd2543a1915532e51a80e8e39bcc57ecbb7ca3 Mon Sep 17 00:00:00 2001
From: Dylan McKay <me@dylanmckay.io>
Date: Fri, 30 Oct 2020 01:04:47 +1300
Subject: [PATCH] Use volatile write operation for 'set_mask_raw' function

The other methods had previously been updated to use volatile memops,
but due to an oversight this method was missed.

Fixes avr-rust/ruduino#31.

Thanks to @MalteT for reporting this issue.
---
 src/register.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/register.rs b/src/register.rs
index 4491c1b..f97933c 100644
--- a/src/register.rs
+++ b/src/register.rs
@@ -52,7 +52,7 @@ pub trait Register : Sized {
     #[inline(always)]
     fn set_mask_raw(mask: Self::T) {
         unsafe {
-            *Self::ADDRESS |= mask;
+            core::ptr::write_volatile(Self::ADDRESS, core::ptr::read_volatile(Self::ADDRESS) | mask);
         }
     }