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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5975DC433EF for ; Thu, 14 Apr 2022 21:15:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343832AbiDNVRW (ORCPT ); Thu, 14 Apr 2022 17:17:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40214 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237304AbiDNVRV (ORCPT ); Thu, 14 Apr 2022 17:17:21 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7D2A1C6EE9; Thu, 14 Apr 2022 14:14:55 -0700 (PDT) Received: from [IPV6:2a00:5f00:102:0:10b3:10ff:fe5d:4ec1] (unknown [IPv6:2a00:5f00:102:0:10b3:10ff:fe5d:4ec1]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: dmitry.osipenko) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id 54D001F47CE5; Thu, 14 Apr 2022 22:14:51 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1649970894; bh=45lr61m9iGCAZVul+Bks15jmw1Puw71mKHjjKMgF/kM=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=Z1NujI6mIKhUzAdDTLgfe8GrUrwpKOSR6x8xb5pLrzSROOZ3WVyixGEZewDfcBvnD P063OzaVG/nS32pSgW2G+PASJqmH+kkKOxtrga3gqPlpZuj7dKiJ2pJPGTzVbEhgl3 iq6LpeR7t/3zcsxh9OvEpdEj1mPR7VIUUS3Bc8vYvVxGCmrG1R+sZpqRNCxU5h69lh z2zqC2s4wGNkyrcZNtZ8nxNAMls04YXtSQhrjpyjLEwfcmvXr/KciGv62UvQoqwd3z qxReZqmSGaVfC9deQI+E8mU2/q/bO2G2vPP2w4iVrZukDQ1WtTTV3hKVDfHJp0ABwm +3QvheM+aNOAA== Message-ID: <274d09f6-2d07-920b-661b-95d899262c9b@collabora.com> Date: Fri, 15 Apr 2022 00:14:47 +0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: [Patch v7 2/4] memory: tegra: Add MC error logging on tegra186 onward Content-Language: en-US To: Ashish Mhetre , digetx@gmail.com, krzysztof.kozlowski@linaro.org, thierry.reding@gmail.com, jonathanh@nvidia.com, robh+dt@kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-tegra@vger.kernel.org, krzysztof.kozlowski+dt@linaro.org Cc: vdumpa@nvidia.com, Snikam@nvidia.com References: <20220413094012.13589-1-amhetre@nvidia.com> <20220413094012.13589-3-amhetre@nvidia.com> <534dbd19-b43b-63e6-69e0-3441dd224ef0@nvidia.com> From: Dmitry Osipenko In-Reply-To: <534dbd19-b43b-63e6-69e0-3441dd224ef0@nvidia.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-tegra@vger.kernel.org On 4/14/22 08:31, Ashish Mhetre wrote: > > > On 4/14/2022 2:43 AM, Dmitry Osipenko wrote: >> External email: Use caution opening links or attachments >> >> >> On 4/13/22 12:40, Ashish Mhetre wrote: >>> +irqreturn_t tegra30_mc_handle_irq(int irq, void *data) >>>   { >>>        struct tegra_mc *mc = data; >>> +     unsigned int bit, channel; >>>        unsigned long status; >>> -     unsigned int bit; >>> >>> -     /* mask all interrupts to avoid flooding */ >>> -     status = mc_readl(mc, MC_INTSTATUS) & mc->soc->intmask; >>> +     if (mc->soc->num_channels) { >>> +             u32 global_status; >>> +             int err; >>> + >>> +             global_status = mc_ch_readl(mc, MC_BROADCAST_CHANNEL, >>> MC_GLOBAL_INTSTATUS); >> >> This will crash if mc->bcast_ch_regs = ERR_PTR(-EINVAL) for older dtbs. > > Actually interrupts won't occur till we write MC_INTMASK register from > broadcast channel with appropriate intmask value. I have added check in > tegra_mc_probe() while registering irq which will write MC_INTMASK from > broadcast only when mc->bcast_ch_regs is initialized i.e. > !IS_ERR(mc->bcast_ch_regs). > So interrupt handler won't be triggered at all if > mc->bcast_ch_regs = ERR_PTR(-EINVAL). > Should be cleaner to set mc->bcast_ch_regs to NULL anyways. The ERR_PTR doesn't add much value and only makes code less readable.