[6/6] drivers/tty/hvc: remove unexplained "just in case" spin delay

Message ID 20180409054056.27292-7-npiggin@gmail.com
State Superseded
Headers show
Series
  • improve OPAL cosole flushing and locking
Related show

Commit Message

Nicholas Piggin April 9, 2018, 5:40 a.m.
This delay was in the very first OPAL console commit 6.5 years ago.
The firmware console has hardened sufficiently to remove it.

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

Comments

Benjamin Herrenschmidt April 9, 2018, 6:03 a.m. | #1
On Mon, 2018-04-09 at 15:40 +1000, Nicholas Piggin wrote:
> This delay was in the very first OPAL console commit 6.5 years ago.
> The firmware console has hardened sufficiently to remove it.
> 

Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.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 e151cfacf2a7..436b98258e60 100644
> --- a/drivers/tty/hvc/hvc_opal.c
> +++ b/drivers/tty/hvc/hvc_opal.c
> @@ -307,14 +307,8 @@ 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;
> -		}
>  	}
>  }
>

Patch

diff --git a/drivers/tty/hvc/hvc_opal.c b/drivers/tty/hvc/hvc_opal.c
index e151cfacf2a7..436b98258e60 100644
--- a/drivers/tty/hvc/hvc_opal.c
+++ b/drivers/tty/hvc/hvc_opal.c
@@ -307,14 +307,8 @@  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;
-		}
 	}
 }