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=ham 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 11E8AC43603 for ; Wed, 4 Dec 2019 18:02:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D058F2073B for ; Wed, 4 Dec 2019 18:02:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575482577; bh=cUBxm5bpX3BNZcvYOv8A70HiYFqDP/A/TSE0hj9URx0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=BpjZDDlFrjkb/CsIvEfiZ8FcDGl1x/AAuCEluOjRDhA/+anub6zXjPyvUO+jw2ouF iSKmB0Z8UvWn2r/+tCOm73zbBclmlgn/Bf1q3uSLFh/iwiORhZtQGDbdHxxTJRpc8I VcWFasmcUltQc7Gf5Hpy5L05UHE+KhbMLGd+v1xc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729952AbfLDSC4 (ORCPT ); Wed, 4 Dec 2019 13:02:56 -0500 Received: from mail.kernel.org ([198.145.29.99]:45674 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729944AbfLDSCy (ORCPT ); Wed, 4 Dec 2019 13:02:54 -0500 Received: from localhost (unknown [217.68.49.72]) (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 3680C206DF; Wed, 4 Dec 2019 18:02:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575482573; bh=cUBxm5bpX3BNZcvYOv8A70HiYFqDP/A/TSE0hj9URx0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ooGSiKPoBClAUwwsDayXXRIMKCCIXLF2IpjOrokfnEXc7sYH5fJ2tl6tHhFFumQgh Obl0i0aN7AUTCztom4nw1CJ3xmY+iZsVIoFSOFZwpSjzOcIG+r21gi6JZGdZMuW4w4 hXbxXH66ZLms8bqS8CYhiHmsNYCTDaYXoRCP+zCU= 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 4.14 008/209] clk: at91: avoid sleeping early Date: Wed, 4 Dec 2019 18:53:40 +0100 Message-Id: <20191204175322.181704522@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191204175321.609072813@linuxfoundation.org> References: <20191204175321.609072813@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