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=-8.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 342ABC11F67 for ; Thu, 1 Jul 2021 20:25:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 198F961410 for ; Thu, 1 Jul 2021 20:25:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234399AbhGAU2Q (ORCPT ); Thu, 1 Jul 2021 16:28:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56614 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234376AbhGAU2O (ORCPT ); Thu, 1 Jul 2021 16:28:14 -0400 Received: from mail-ot1-x334.google.com (mail-ot1-x334.google.com [IPv6:2607:f8b0:4864:20::334]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 953FBC061762; Thu, 1 Jul 2021 13:25:43 -0700 (PDT) Received: by mail-ot1-x334.google.com with SMTP id t24-20020a9d7f980000b029046f4a1a5ec4so7862387otp.1; Thu, 01 Jul 2021 13:25:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=HKqWSYAw82wkbQb4Q9rpOf6Rzfc8rpUQdtixYTB6Xug=; b=K6Wop/WYm3LBArGs2St5nHMQ6E/PjbobEcxSA5D+GHCcQuVq5Do1OwPJKzz9JvfarD rSpANKv+DJk5rGRpTWVPNOa5ecr/2f7h+N32TlAXgYXBTFzJxVxLpalpEPuiPL+2WcoZ fvsAMDEQHCl/RMF7bDSQ5EbuieQiXB7I/a02KdGfJRuDF7mAEIYFpbuifQUkWYlIO3nF YkbtMk6s7DrY79xfEKz3DdOdlnbejiHyvt/W2AtzwYoolQ9nGt+nFSv+7uvMOpbZxVTG G7/Fz4sTqGEYOeb6Q4/zpQQS8lNXEdC+ReukjRBWgrgLdZFyPgaRAeg71tUiGnikJF7o 7ZwQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=HKqWSYAw82wkbQb4Q9rpOf6Rzfc8rpUQdtixYTB6Xug=; b=XfLh/s7bYGd+qqYRb6Rcu3IhN2t0gQEb/f+ZNWQoOlyi497VYD1PHA00iQ8MjVp7xU sNKHbkfylPUflU6tssqghqkxSuZeUXb6fSlgIJkf5H95xasXqRRQgd1dvpwVPoLAzNdt aGO6UKcAx3/QBeVYsh95yYBDH+Vew16DZDF0vHodmWdVtkqDNPtDcCARamRpDaAK80ca nW+4wJOv9C4RiEVcAnkHiyCRejzkdWIPM8v9W09yenS2wF19bxVljf5PtygEJwoWwxdJ kDjfE1qOdDtA1ikFG8rjm2//ryMsd5uphPlMyRmLpd9s+D6IPF0LqhrU5Ni4r/qym3N5 qOEQ== X-Gm-Message-State: AOAM533IQ5e4x08sMARht0zT2M9lwkFconx0BFDmPB09InvWmpFxyuo7 5obD4RIG3PfgzJi904/T8GpQuk40LsQ= X-Google-Smtp-Source: ABdhPJxbB5Kww3hYnu7vJrtKW5rPQ5KozsuVH/SGKSsrpAlj+tPI1lYQs2ly5JQ3p0izlW1T70B9GA== X-Received: by 2002:a05:6830:241d:: with SMTP id j29mr1477463ots.371.1625171142913; Thu, 01 Jul 2021 13:25:42 -0700 (PDT) Received: from localhost ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id y5sm159294otq.5.2021.07.01.13.25.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 01 Jul 2021 13:25:42 -0700 (PDT) Sender: Guenter Roeck Date: Thu, 1 Jul 2021 13:25:40 -0700 From: Guenter Roeck To: Martin Blumenstingl Cc: mturquette@baylibre.com, sboyd@kernel.org, linux-clk@vger.kernel.org, narmstrong@baylibre.com, jbrunet@baylibre.com, khilman@baylibre.com, linux-kernel@vger.kernel.org, linux-amlogic@lists.infradead.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v3 2/3] clk: divider: Switch from .round_rate to .determine_rate by default Message-ID: <20210701202540.GA1085600@roeck-us.net> References: <20210627223959.188139-1-martin.blumenstingl@googlemail.com> <20210627223959.188139-3-martin.blumenstingl@googlemail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210627223959.188139-3-martin.blumenstingl@googlemail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 28, 2021 at 12:39:58AM +0200, Martin Blumenstingl wrote: > .determine_rate is meant to replace .round_rate. The former comes with a > benefit which is especially relevant on 32-bit systems: since > .determine_rate uses an "unsigned long" (compared to a "signed long" > which is used by .round_rate) the maximum value on 32-bit systems > increases from 2^31 (or approx. 2.14GHz) to 2^32 (or approx. 4.29GHz). > Switch to a .determine_rate implementation by default so 32-bit systems > can benefit from the increased maximum value as well as so we have one > fewer user of .round_rate. > > Reviewed-by: Jerome Brunet > Signed-off-by: Martin Blumenstingl In next-20210701: 0.000000] 8<--- cut here --- [ 0.000000] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [ 0.000000] pgd = (ptrval) [ 0.000000] [00000000] *pgd=00000000 [ 0.000000] Internal error: Oops: 80000005 [#1] SMP ARM [ 0.000000] Modules linked in: [ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.13.0-next-20210701 #1 [ 0.000000] Hardware name: Freescale i.MX6 Ultralite (Device Tree) [ 0.000000] PC is at 0x0 [ 0.000000] LR is at clk_core_determine_round_nolock+0xb4/0xe0 [ 0.000000] pc : [<00000000>] lr : [] psr: a00000d3 [ 0.000000] sp : c1701e48 ip : 00000000 fp : c1f6b340 [ 0.000000] r10: c1f6b33c r9 : d082007c r8 : c1709a18 [ 0.000000] r7 : 05e69ec0 r6 : 00000000 r5 : c1701e58 r4 : c2090480 [ 0.000000] r3 : 00000000 r2 : c1701e64 r1 : 05e69ec0 r0 : c208fe80 [ 0.000000] Flags: NzCv IRQs off FIQs off Mode SVC_32 ISA ARM Segment none [ 0.000000] Control: 10c5387d Table: 8000406a DAC: 00000051 [ 0.000000] Register r0 information: slab kmalloc-64 start c208fe80 pointer offset 0 size 64 [ 0.000000] Register r1 information: non-paged memory [ 0.000000] Register r2 information: non-slab/vmalloc memory [ 0.000000] Register r3 information: NULL pointer [ 0.000000] Register r4 information: slab kmalloc-192 start c2090480 pointer offset 0 size 192 [ 0.000000] Register r5 information: non-slab/vmalloc memory [ 0.000000] Register r6 information: NULL pointer [ 0.000000] Register r7 information: non-paged memory [ 0.000000] Register r8 information: non-slab/vmalloc memory [ 0.000000] Register r9 information: 0-page vmalloc region starting at 0xd0820000 allocated at of_iomap+0x4c/0x68 [ 0.000000] Register r10 information: non-slab/vmalloc memory [ 0.000000] Register r11 information: non-slab/vmalloc memory [ 0.000000] Register r12 information: NULL pointer [ 0.000000] Process swapper/0 (pid: 0, stack limit = 0x(ptrval)) [ 0.000000] Stack: (0xc1701e48 to 0xc1702000) [ 0.000000] 1e40: c2090480 c1700000 00000000 c07c5480 05e69ec0 00000000 [ 0.000000] 1e60: ffffffff 179a7b00 c208d500 e6ff0344 c208ff00 05e69ec0 d0820080 00000000 [ 0.000000] 1e80: 0000001c c07c55c0 c1f6b324 c2012c04 d0820080 c163c310 c1f6b340 00000000 [ 0.000000] 1ea0: 00000804 d0820074 0000001c 00000000 c186052c c109a5b0 c186052c c0caf26c [ 0.000000] 1ec0: cbdc67ac d0820000 c2012c04 d0820060 d0820048 d0820028 cbdcc0cc d0820018 [ 0.000000] 1ee0: d0820020 d0820038 d0820030 c2012c04 c1701f1c 00000000 c2005e80 c1701f1c [ 0.000000] 1f00: 00000004 c2005e88 cbdcc0cc cbdcc138 00000001 c162a4e4 c1700000 c1700000 [ 0.000000] 1f20: 00000000 c2005e88 c2005e88 cbdc5884 00000000 c1701fc8 c17093cc c0838f44 [ 0.000000] 1f40: c1600dd0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 0.000000] 1f60: 00000000 00000000 00000000 00000000 00000000 e6ff0344 00000000 c1902000 [ 0.000000] 1f80: c1663a80 00000012 c1700000 c1709380 00000000 c170caa8 c14cb424 c1604d34 [ 0.000000] 1fa0: c1902000 c1600e0c ffffffff ffffffff 00000000 c1600588 00000000 c1700000 [ 0.000000] 1fc0: 00000000 c1663a80 e6fa0e44 00000000 00000000 c1600330 00000051 10c0387d [ 0.000000] 1fe0: ffffffff 8833b000 410fc075 10c5387d 00000000 00000000 00000000 00000000 [ 0.000000] [] (clk_core_determine_round_nolock) from [] (clk_core_set_rate_nolock+0x184/0x294) [ 0.000000] [] (clk_core_set_rate_nolock) from [] (clk_set_rate+0x30/0x64) [ 0.000000] [] (clk_set_rate) from [] (imx6ul_clocks_init+0x2798/0x2a44) [ 0.000000] [] (imx6ul_clocks_init) from [] (of_clk_init+0x180/0x26c) [ 0.000000] [] (of_clk_init) from [] (time_init+0x20/0x30) [ 0.000000] [] (time_init) from [] (start_kernel+0x4c8/0x6cc) [ 0.000000] [] (start_kernel) from [<00000000>] (0x0) [ 0.000000] Code: bad PC value [ 0.000000] ---[ end trace 7009a0f298fd39e9 ]--- [ 0.000000] Kernel panic - not syncing: Attempted to kill the idle task! Bisct points to this patch as culprit. Reverting it fixes the problem. Guenter