From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752281AbdFAQVE (ORCPT ); Thu, 1 Jun 2017 12:21:04 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33282 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752082AbdFAPoy (ORCPT ); Thu, 1 Jun 2017 11:44:54 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Charles Keepax" , "Nicholas Mc Guire" , "Stephen Boyd" Date: Thu, 01 Jun 2017 16:43:15 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 019/212] clk: wm831x: fix usleep_range with bad range In-Reply-To: X-SA-Exim-Connect-IP: 82.70.136.246 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.44-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Nicholas Mc Guire commit ed784c532a3d0959db488f40a96c5127f63d42dc upstream. The delay here is not in atomic context and does not seem critical with respect to precision, but usleep_range(min,max) with min==max results in giving the timer subsystem no room to optimize uncritical delays. Fix this by setting the range to 2000,3000 us. Fixes: commit f05259a6ffa4 ("clk: wm831x: Add initial WM831x clock driver") Signed-off-by: Nicholas Mc Guire Acked-by: Charles Keepax Signed-off-by: Stephen Boyd Signed-off-by: Ben Hutchings --- drivers/clk/clk-wm831x.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/clk/clk-wm831x.c +++ b/drivers/clk/clk-wm831x.c @@ -102,7 +102,8 @@ static int wm831x_fll_prepare(struct clk if (ret != 0) dev_crit(wm831x->dev, "Failed to enable FLL: %d\n", ret); - usleep_range(2000, 2000); + /* wait 2-3 ms for new frequency taking effect */ + usleep_range(2000, 3000); return ret; }