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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 3F5D9C432C0 for ; Tue, 3 Dec 2019 22:45:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0D6A92073C for ; Tue, 3 Dec 2019 22:45:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575413143; bh=cUBxm5bpX3BNZcvYOv8A70HiYFqDP/A/TSE0hj9URx0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=iRYWMCDA0AkPwuiTU1QDm7zAlwSwY79AyRdZ8XRpaNKYM3l7Nf2V4gCm/z4xHEG3h cSdxFljKUR349UUNvPFkQ1HOEzRrSckWNf27NTS2w4Ez6tXksSQVVJlbcklqMJ75Vy r73b8LGGcnvb6AGchtyE8yn13F/UAQhmcxfvEaHg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728822AbfLCWpl (ORCPT ); Tue, 3 Dec 2019 17:45:41 -0500 Received: from mail.kernel.org ([198.145.29.99]:34262 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729075AbfLCWpg (ORCPT ); Tue, 3 Dec 2019 17:45:36 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7434720803; Tue, 3 Dec 2019 22:45:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575413135; bh=cUBxm5bpX3BNZcvYOv8A70HiYFqDP/A/TSE0hj9URx0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nyxwLgA4x6EXFweshLoXkl5WwJbVI7sdNUxg/Cl4YaZtRhb8kkEhRnlBI1dTHCEIo NOWpyrIW7Lwtxe5NKIYrq8U1APkBrlnAXWOjgbRc1nHa3S+VEdOhyU6g4lVkabDhja cstrrUBF1mZnXfsGBA5ScFzrze6IrRYiJp5T0Qa8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , Alexandre Belloni , Stephen Boyd , Sasha Levin Subject: [PATCH 4.19 013/321] clk: at91: avoid sleeping early Date: Tue, 3 Dec 2019 23:31:19 +0100 Message-Id: <20191203223427.809547362@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191203223427.103571230@linuxfoundation.org> References: <20191203223427.103571230@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Alexandre Belloni [ Upstream commit 658fd65cf0b0d511de1718e48d9a28844c385ae0 ] 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 Signed-off-by: Sasha Levin --- drivers/clk/at91/clk-main.c | 5 ++++- drivers/clk/at91/sckc.c | 20 ++++++++++++++++---- 2 files changed, 20 insertions(+), 5 deletions(-) diff --git a/drivers/clk/at91/clk-main.c b/drivers/clk/at91/clk-main.c index 2f97a843d6d6b..fb5c14af8cc8d 100644 --- a/drivers/clk/at91/clk-main.c +++ b/drivers/clk/at91/clk-main.c @@ -354,7 +354,10 @@ static int clk_main_probe_frequency(struct regmap *regmap) regmap_read(regmap, AT91_CKGR_MCFR, &mcfr); if (mcfr & 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; diff --git a/drivers/clk/at91/sckc.c b/drivers/clk/at91/sckc.c index ab6ecefc49ad8..43ba2a8b03faf 100644 --- a/drivers/clk/at91/sckc.c +++ b/drivers/clk/at91/sckc.c @@ -74,7 +74,10 @@ static int clk_slow_osc_prepare(struct clk_hw *hw) 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; } @@ -197,7 +200,10 @@ static int clk_slow_rc_osc_prepare(struct clk_hw *hw) 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; } @@ -310,7 +316,10 @@ static int clk_sam9x5_slow_set_parent(struct clk_hw *hw, u8 index) 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; } @@ -443,7 +452,10 @@ static int clk_sama5d4_slow_osc_prepare(struct clk_hw *hw) return 0; } - 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); osc->prepared = true; return 0; -- 2.20.1