From: Giuliano Pochini <pochini@shiny.it>
Date: Mon, 17 Sep 2007 10:49:40 +0000 (+0200)
Subject: [ALSA] echoaudio - Add barrier() to prevent compiler optimization
X-Git-Tag: v2.6.24-rc1~832^2~53
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=22d3a20030439420bf2795c60529ba0e89b4d82c;p=linux.git

[ALSA] echoaudio - Add barrier() to prevent compiler optimization

This patch adds a barrier() to prevent the compiler from
moving the read outside of the loop. It also fixes a comment.

Signed-off-by: Giuliano Pochini <pochini@shiny.it>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
---

diff --git a/sound/pci/echoaudio/echoaudio_dsp.c b/sound/pci/echoaudio/echoaudio_dsp.c
index 42afa837d9b4..e6c100770392 100644
--- a/sound/pci/echoaudio/echoaudio_dsp.c
+++ b/sound/pci/echoaudio/echoaudio_dsp.c
@@ -43,11 +43,11 @@ static int wait_handshake(struct echoaudio *chip)
 {
 	int i;
 
-	/* Wait up to 10ms for the handshake from the DSP */
+	/* Wait up to 20ms for the handshake from the DSP */
 	for (i = 0; i < HANDSHAKE_TIMEOUT; i++) {
 		/* Look for the handshake value */
+		barrier();
 		if (chip->comm_page->handshake) {
-			/*if (i)  DE_ACT(("Handshake time: %d\n", i));*/
 			return 0;
 		}
 		udelay(1);