From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B3E7C43603 for ; Tue, 17 Dec 2019 00:53:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6A1A824679 for ; Tue, 17 Dec 2019 00:53:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728039AbfLQAxo (ORCPT ); Mon, 16 Dec 2019 19:53:44 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:35430 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727125AbfLQAvo (ORCPT ); Mon, 16 Dec 2019 19:51:44 -0500 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1ih15L-0003Mi-Di; Tue, 17 Dec 2019 00:51:35 +0000 Received: from ben by deadeye with local (Exim 4.93-RC7) (envelope-from ) id 1ih15J-0005ap-CP; Tue, 17 Dec 2019 00:51:33 +0000 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, Denis Kirjanov , "Uwe Kleine-=?UTF-8?Q?K=C3=B6nig?=" , "Stephen Boyd" , "Alexandre Belloni" Date: Tue, 17 Dec 2019 00:47:11 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 097/136] clk: at91: avoid sleeping early In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.80-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Alexandre Belloni commit 658fd65cf0b0d511de1718e48d9a28844c385ae0 upstream. It is not allowed to sleep to early in the boot process and this may lead to kernel issues if the bootloader didn't prepare the slow clock and main clock. This results in the following error and dump stack on the AriettaG25: bad: scheduling from the idle thread! Ensure it is possible to sleep, else simply have a delay. Reported-by: Uwe Kleine-König Signed-off-by: Alexandre Belloni Link: https://lkml.kernel.org/r/20190920153906.20887-1-alexandre.belloni@bootlin.com Fixes: 80eded6ce8bb ("clk: at91: add slow clks driver") Tested-by: Uwe Kleine-König Signed-off-by: Stephen Boyd [bwh: Backported to 3.16: - Drop changes in clk_sama5d4_slow_osc_prepare() - Adjust filename, context] Signed-off-by: Ben Hutchings --- drivers/clk/at91/clk-main.c | 5 ++++- drivers/clk/at91/clk-slow.c | 20 ++++++++++++++++---- 2 files changed, 20 insertions(+), 5 deletions(-) --- a/drivers/clk/at91/clk-main.c +++ b/drivers/clk/at91/clk-main.c @@ -374,7 +374,10 @@ static int clk_main_probe_frequency(stru tmp = pmc_read(pmc, AT91_CKGR_MCFR); if (tmp & AT91_PMC_MAINRDY) return 0; - usleep_range(MAINF_LOOP_MIN_WAIT, MAINF_LOOP_MAX_WAIT); + if (system_state < SYSTEM_RUNNING) + udelay(MAINF_LOOP_MIN_WAIT); + else + usleep_range(MAINF_LOOP_MIN_WAIT, MAINF_LOOP_MAX_WAIT); } while (time_before(prep_time, timeout)); return -ETIMEDOUT; --- a/drivers/clk/at91/clk-slow.c +++ b/drivers/clk/at91/clk-slow.c @@ -83,7 +83,10 @@ static int clk_slow_osc_prepare(struct c writel(tmp | AT91_SCKC_OSC32EN, sckcr); - usleep_range(osc->startup_usec, osc->startup_usec + 1); + if (system_state < SYSTEM_RUNNING) + udelay(osc->startup_usec); + else + usleep_range(osc->startup_usec, osc->startup_usec + 1); return 0; } @@ -202,7 +205,10 @@ static int clk_slow_rc_osc_prepare(struc writel(readl(sckcr) | AT91_SCKC_RCEN, sckcr); - usleep_range(osc->startup_usec, osc->startup_usec + 1); + if (system_state < SYSTEM_RUNNING) + udelay(osc->startup_usec); + else + usleep_range(osc->startup_usec, osc->startup_usec + 1); return 0; } @@ -311,7 +317,10 @@ static int clk_sam9x5_slow_set_parent(st writel(tmp, sckcr); - usleep_range(SLOWCK_SW_TIME_USEC, SLOWCK_SW_TIME_USEC + 1); + if (system_state < SYSTEM_RUNNING) + udelay(SLOWCK_SW_TIME_USEC); + else + usleep_range(SLOWCK_SW_TIME_USEC, SLOWCK_SW_TIME_USEC + 1); return 0; }