From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Nicholas Piggin <npiggin@gmail.com>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jslaby@suse.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH 09/15] tty: hvc: remove unexplained "just in case" spin delay
Date: Tue, 1 May 2018 00:55:52 +1000 [thread overview]
Message-ID: <20180430145558.4308-10-npiggin@gmail.com> (raw)
In-Reply-To: <20180430145558.4308-1-npiggin@gmail.com>
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@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 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
next prev parent reply other threads:[~2018-04-30 14:55 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-30 14:55 [PATCH 00/15] hvc and powerpc opal console latency reduction Nicholas Piggin
2018-04-30 14:55 ` [PATCH 01/15] powerpc/powernv: opal_put_chars partial write fix Nicholas Piggin
2018-07-24 13:59 ` [01/15] " Michael Ellerman
2018-04-30 14:55 ` [PATCH 02/15] powerpc/powernv: Fix OPAL console driver OPAL_BUSY loops Nicholas Piggin
2018-04-30 14:55 ` [PATCH 03/15] powerpc/powernv: opal-kmsg standardise OPAL_BUSY handling Nicholas Piggin
2018-04-30 14:55 ` [PATCH 04/15] powerpc/powernv: opal-kmsg use flush fallback from console code Nicholas Piggin
2018-05-04 5:16 ` Michael Ellerman
2018-05-04 5:37 ` Nicholas Piggin
2018-05-07 10:36 ` Michael Ellerman
2018-05-08 3:40 ` Nicholas Piggin
2018-04-30 14:55 ` [PATCH 05/15] powerpc/powernv: Implement and use opal_flush_console Nicholas Piggin
2018-04-30 14:55 ` [PATCH 06/15] powerpc/powernv: Remove OPALv1 support from opal console driver Nicholas Piggin
2018-04-30 14:55 ` [PATCH 07/15] powerpc/powernv: move opal console flushing to udbg Nicholas Piggin
2018-04-30 14:55 ` [PATCH 08/15] powerpc/powernv: implement opal_put_chars_atomic Nicholas Piggin
2018-05-01 9:48 ` Benjamin Herrenschmidt
2018-05-01 10:37 ` Nicholas Piggin
2018-05-07 10:35 ` Michael Ellerman
2018-05-08 3:36 ` Nicholas Piggin
2018-04-30 14:55 ` Nicholas Piggin [this message]
2018-04-30 14:55 ` [PATCH 10/15] tty: hvc: use mutex instead of spinlock for hvc_structs lock Nicholas Piggin
2018-08-13 11:22 ` [10/15] " Michael Ellerman
2018-04-30 14:55 ` [PATCH 11/15] tty: hvc: hvc_poll break hv read loop Nicholas Piggin
2018-08-13 11:23 ` [11/15] " Michael Ellerman
2018-04-30 14:55 ` [PATCH 12/15] tty: hvc: hvc_poll may sleep Nicholas Piggin
2018-08-13 11:23 ` [12/15] " Michael Ellerman
2018-04-30 14:55 ` [PATCH 13/15] tty: hvc: hvc_write " Nicholas Piggin
2018-08-13 11:23 ` [13/15] " Michael Ellerman
2018-04-30 14:55 ` [PATCH 14/15] tty: hvc: introduce the hv_ops.flush operation for hvc drivers Nicholas Piggin
2018-08-13 11:23 ` [14/15] " Michael Ellerman
2018-04-30 14:55 ` [PATCH 15/15] powerpc/powernv: provide a console flush operation for opal hvc driver Nicholas Piggin
2018-08-21 10:35 ` [15/15] " Michael Ellerman
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