From b08ed20e5faa75279462e6bd6ddf0c956e7106fb Mon Sep 17 00:00:00 2001
From: Floris Bos <bos@je-eigen-domein.nl>
Date: Sat, 23 May 2020 21:40:52 +0200
Subject: [PATCH] Linux: enable direct IO for verify

Linux has huge buffer cache (all free memory)
So make sure we are reading data back from the actual card instead
of cache.
---
 downloadthread.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/downloadthread.cpp b/downloadthread.cpp
index 8a62e4e..2516230 100644
--- a/downloadthread.cpp
+++ b/downloadthread.cpp
@@ -603,6 +603,11 @@ bool DownloadThread::_verify()
     QElapsedTimer t1;
     t1.start();
 
+#ifdef Q_OS_LINUX
+    /* Make sure we are reading from the drive and not from cache */
+    fcntl(_file.handle(), F_SETFL, O_DIRECT | fcntl(_file.handle(), F_GETFL));
+#endif
+
     if (!_firstBlock)
     {
         _file.seek(0);