linux-kernel - [PATCH 09/15] tty: hvc: remove unexplained "just in case" spin delay

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Date:   Tue,  1 May 2018 00:55:52 +1000
From:   Nicholas Piggin <npiggin@...il.com>
To:     linuxppc-dev@...ts.ozlabs.org
Cc:     Nicholas Piggin <npiggin@...il.com>,
        Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Jiri Slaby <jslaby@...e.com>, linux-kernel@...r.kernel.org
Subject: [PATCH 09/15] tty: hvc: remove unexplained "just in case" spin delay

This delay was in the very first OPAL console commit 6.5 years ago,
and came from the vio hvc driver. The firmware console has hardened
sufficiently to remove it.

Reviewed-by: Benjamin Herrenschmidt <benh@...nel.crashing.org>
Signed-off-by: Nicholas Piggin <npiggin@...il.com>
---
 drivers/tty/hvc/hvc_opal.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/drivers/tty/hvc/hvc_opal.c b/drivers/tty/hvc/hvc_opal.c
index 0a72f98ee082..786e76a1e06d 100644
--- a/drivers/tty/hvc/hvc_opal.c
+++ b/drivers/tty/hvc/hvc_opal.c
@@ -313,14 +313,8 @@ static int udbg_opal_getc(void)
 	int ch;
 	for (;;) {
 		ch = udbg_opal_getc_poll();
-		if (ch == -1) {
-			/* This shouldn't be needed...but... */
-			volatile unsigned long delay;
-			for (delay=0; delay < 2000000; delay++)
-				;
-		} else {
+		if (ch != -1)
 			return ch;
-		}
 	}
 }
 
-- 
2.17.0