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=-12.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 52665C2D0A8 for ; Mon, 28 Sep 2020 08:48:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0CBE921531 for ; Mon, 28 Sep 2020 08:48:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="tW1BN7cy" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726497AbgI1IsA (ORCPT ); Mon, 28 Sep 2020 04:48:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43608 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726328AbgI1IsA (ORCPT ); Mon, 28 Sep 2020 04:48:00 -0400 Received: from mail-pj1-x1043.google.com (mail-pj1-x1043.google.com [IPv6:2607:f8b0:4864:20::1043]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 942E8C0613CE for ; Mon, 28 Sep 2020 01:48:00 -0700 (PDT) Received: by mail-pj1-x1043.google.com with SMTP id mn7so230906pjb.5 for ; Mon, 28 Sep 2020 01:48:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id; bh=wY/Phh7haMCfrTDSqngzJDGR4pk8ZSUHFlVi1FrntNA=; b=tW1BN7cydHn8bciyQaMKZ51ecy0MhjdVxSWTovppv/D74ZDTobDVJ2HUeOgH6w+c/j U4S6rFlt/0Ym+XqpJ4b9S+ygvml27p3t1rLCUrAiAePqVGfvdgO85F/5H2m1GIpLqJJm sK2jICuluuxBGOtDL5twBNxIQqclFgY9q/TyrzlRDxR1pwJEcxBzP0aWgtItW7RF8A7R aTbasQaNJ2ffSJ6wudKkStpLWuBppzIf8gPBcpFF+ygNay8/5SGAGoQFSNQhUSs6quPh cQSddtkGeY7gWkn6mE85GMYYvZLeNqifBIknRvD+C+1YpdIhJamerVYyxiAtrrH2Eei+ GM6Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=wY/Phh7haMCfrTDSqngzJDGR4pk8ZSUHFlVi1FrntNA=; b=q4CPR0CEqtBbE4mSg12ZPFa4iUzNd0W3cc6RjD47D/jF4gfmNMW3laqsc1oLZXcgPA kwmZ4i2sRhtR5zI9ZaSmIFWQVz0wuHRAj4D+aoqeuvxMdzMwZuHhVPU/tNEFAWAKBdL8 oTeemyVLk9bIjtos3vMNnujPc9QGlNLGG7nswG827XqCt9emBWrpXPuZB7zr+hh6uYTL 9xpHq3goLNtyv8jRlYr3Ne2KceuthvSMM0IiswcaQ66e5Od2oFlLDCDko6XPWKgCSVQk rTshjIqWJWJooXYASqUvM7FQZu88uZQufqtgzj2Pd2D2wWRP36bAjcHQHPqjoDR+SKMp mUqg== X-Gm-Message-State: AOAM531MBYucAMNzoMIzERdBBrZOqw4Lp9tnLdskvbFAqUdEzIgKsM6u PNKJdl3sLTzAD0LavdeHatSUew== X-Google-Smtp-Source: ABdhPJye6u3HOi8ZQVN02jipYNmuwO9krjvzCg+PZj+Fb/NHiBRugHZMXouOiOECLimIC0oDDjZmzA== X-Received: by 2002:a17:90a:9505:: with SMTP id t5mr380570pjo.121.1601282880163; Mon, 28 Sep 2020 01:48:00 -0700 (PDT) Received: from localhost.localdomain (li519-153.members.linode.com. [66.175.222.153]) by smtp.gmail.com with ESMTPSA id u18sm623181pgk.18.2020.09.28.01.47.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 28 Sep 2020 01:47:59 -0700 (PDT) From: Jun Nie To: sboyd@codeaurora.org, mturquette@baylibre.com, linux-clk@vger.kernel.org Cc: shawn.guo@linaro.org, Jun Nie Subject: [PATCH] clk: emit warning if fail to get parent clk Date: Mon, 28 Sep 2020 16:47:44 +0800 Message-Id: <20200928084744.32478-1-jun.nie@linaro.org> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org Emit warning if fail to get parent clk to expose potential issue earlier. For example, clk_hw_get_rate() will return 0 for a clock without parent core while parent number is not zero. This cause opp always think it is switching frequency from 0 to some other frequency. Crash may happen if we switch from high frequency to low frequency and lower CPU voltage before clk rate switching. Signed-off-by: Jun Nie --- drivers/clk/clk.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 1a27e99ccb17..78b21b888e56 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -424,6 +424,7 @@ static void clk_core_fill_parent_index(struct clk_core *core, u8 index) { struct clk_parent_map *entry = &core->parents[index]; struct clk_core *parent = ERR_PTR(-ENOENT); + int emit_warn = 0; if (entry->hw) { parent = entry->hw->core; @@ -443,6 +444,12 @@ static void clk_core_fill_parent_index(struct clk_core *core, u8 index) /* Only cache it if it's not an error */ if (!IS_ERR(parent)) entry->core = parent; + else if (parent != ERR_PTR(-EPROBE_DEFER)) + emit_warn = 1; + + if (emit_warn || (!parent && core->num_parents)) + pr_warn("Fail to get indexed %d parent for clk %s.", + index, core->name); } static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core, -- 2.17.1