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=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 0F7D6C47254 for ; Sat, 2 May 2020 17:16:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E20CC20787 for ; Sat, 2 May 2020 17:16:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="gV2H5xW2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728412AbgEBRQB (ORCPT ); Sat, 2 May 2020 13:16:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55964 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1728342AbgEBRQA (ORCPT ); Sat, 2 May 2020 13:16:00 -0400 Received: from mail-wr1-x442.google.com (mail-wr1-x442.google.com [IPv6:2a00:1450:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7F3CDC061A0C; Sat, 2 May 2020 10:16:00 -0700 (PDT) Received: by mail-wr1-x442.google.com with SMTP id k1so15696290wrx.4; Sat, 02 May 2020 10:16:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=3PIv3g2HbrGzdAz/fXXsONdZmu8F6RevQt0D1oDmLho=; b=gV2H5xW2mTm8uTHZxOra8ob6JuAmi+h8HkRMipd8wXZ39Cl03adTXtuChzdjwVBSqF T7DTCpK499L13ogQPCODo8zyTDIWQ76Tz5oqsTfbpYK6PG9lo7kHlb2q9swyz2N8HdXU I/91hszWw5NKt63LjSaIHT+1bKVHdthB2Gh+gAJKYd8BaDK5sVG32omy1ajV5qdQu1jR pSOTekjzBaOHFNJJGxQgRiP2Kv7YSXmGmDNTZ0XouvsoW9j755qByUUsKtTm82DtFs3+ WJGEXXPvnnhguH+LqS0Lk/X7kFXITvV9HJMXY11u/TvpixyqRllu2AnH4NxUpFNqt8HN F/sQ== 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:mime-version :content-transfer-encoding; bh=3PIv3g2HbrGzdAz/fXXsONdZmu8F6RevQt0D1oDmLho=; b=r8MK6SM/943HCYeOoEMPzfRNZaVnBqA2dPBaYm7gYgyhYzQIZ61yQdbX0CjsQ/JMw6 Gk1RaMd9gmtfjn+x23QgGSypRU9viV6cFnnt3Saky4up8NGZyQzGmfjqCqtMYtsqKB9z 5CVZ56+zVQ6VoxevXTzo2AI3/FAfI33ZQkg7RdpqMxD4yg7pU+eEPVHMe84+nl261Q2k mNeYlS9P2Z72NziwrLEcZ5B6f3Di8GcdJ0LmvX8hb8zAf4n54R7/ZtB69NwMmIZUgHqy qAdEUwV2QWZ2t97Yjqo7/Lx2bX4zxjf4nOC03cK8/zMjTXxdwOjYBo9csiZ4wIhB0mjt tXWA== X-Gm-Message-State: AGi0PubWyG2GXjBDryUJG4G0IT3k0J3680KaTUVzbfXG38sL49w2CrOj YBvmtW8TAJwBqtRC5gPS8F4= X-Google-Smtp-Source: APiQypJbj1yl/89EsQl/nrkDrS2TuUaoAtTtpOQQOr9z/uF7PiIxOkiRtxQr8HtZ77MS6EtBt2jRAA== X-Received: by 2002:a5d:6a8b:: with SMTP id s11mr9916966wru.258.1588439753785; Sat, 02 May 2020 10:15:53 -0700 (PDT) Received: from localhost.localdomain ([188.24.130.199]) by smtp.gmail.com with ESMTPSA id k14sm10142090wrp.53.2020.05.02.10.15.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 02 May 2020 10:15:53 -0700 (PDT) From: Cristian Ciocaltea To: Manivannan Sadhasivam , =?UTF-8?q?Andreas=20F=C3=A4rber?= , Vinod Koul Cc: Dan Williams , dmaengine@vger.kernel.org, linux-actions@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 1/1] dmaengine: owl: Use correct lock in owl_dma_get_pchan() Date: Sat, 2 May 2020 20:15:51 +0300 Message-Id: X-Mailer: git-send-email 2.26.2 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 When the kernel is built with lockdep support and the owl-dma driver is used, the following message is shown: [ 2.496939] INFO: trying to register non-static key. [ 2.501889] the code is fine but needs lockdep annotation. [ 2.507357] turning off the locking correctness validator. [ 2.512834] CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.6.3+ #15 [ 2.519084] Hardware name: Generic DT based system [ 2.523878] Workqueue: events_freezable mmc_rescan [ 2.528681] [<801127f0>] (unwind_backtrace) from [<8010da58>] (show_stack+0x10/0x14) [ 2.536420] [<8010da58>] (show_stack) from [<8080fbe8>] (dump_stack+0xb4/0xe0) [ 2.543645] [<8080fbe8>] (dump_stack) from [<8017efa4>] (register_lock_class+0x6f0/0x718) [ 2.551816] [<8017efa4>] (register_lock_class) from [<8017b7d0>] (__lock_acquire+0x78/0x25f0) [ 2.560330] [<8017b7d0>] (__lock_acquire) from [<8017e5e4>] (lock_acquire+0xd8/0x1f4) [ 2.568159] [<8017e5e4>] (lock_acquire) from [<80831fb0>] (_raw_spin_lock_irqsave+0x3c/0x50) [ 2.576589] [<80831fb0>] (_raw_spin_lock_irqsave) from [<8051b5fc>] (owl_dma_issue_pending+0xbc/0x120) [ 2.585884] [<8051b5fc>] (owl_dma_issue_pending) from [<80668cbc>] (owl_mmc_request+0x1b0/0x390) [ 2.594655] [<80668cbc>] (owl_mmc_request) from [<80650ce0>] (mmc_start_request+0x94/0xbc) [ 2.602906] [<80650ce0>] (mmc_start_request) from [<80650ec0>] (mmc_wait_for_req+0x64/0xd0) [ 2.611245] [<80650ec0>] (mmc_wait_for_req) from [<8065aa10>] (mmc_app_send_scr+0x10c/0x144) [ 2.619669] [<8065aa10>] (mmc_app_send_scr) from [<80659b3c>] (mmc_sd_setup_card+0x4c/0x318) [ 2.628092] [<80659b3c>] (mmc_sd_setup_card) from [<80659f0c>] (mmc_sd_init_card+0x104/0x430) [ 2.636601] [<80659f0c>] (mmc_sd_init_card) from [<8065a3e0>] (mmc_attach_sd+0xcc/0x16c) [ 2.644678] [<8065a3e0>] (mmc_attach_sd) from [<8065301c>] (mmc_rescan+0x3ac/0x40c) [ 2.652332] [<8065301c>] (mmc_rescan) from [<80143244>] (process_one_work+0x2d8/0x780) [ 2.660239] [<80143244>] (process_one_work) from [<80143730>] (worker_thread+0x44/0x598) [ 2.668323] [<80143730>] (worker_thread) from [<8014b5f8>] (kthread+0x148/0x150) [ 2.675708] [<8014b5f8>] (kthread) from [<801010b4>] (ret_from_fork+0x14/0x20) [ 2.682912] Exception stack(0xee8fdfb0 to 0xee8fdff8) [ 2.687954] dfa0: 00000000 00000000 00000000 00000000 [ 2.696118] dfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 2.704277] dfe0: 00000000 00000000 00000000 00000000 00000013 00000000 The obvious fix would be to use 'spin_lock_init()' on 'pchan->lock' before attempting to call 'spin_lock_irqsave()' in 'owl_dma_get_pchan()'. However, according to Manivannan Sadhasivam, 'pchan->lock' was supposed to only protect 'pchan->vchan' while 'od->lock' does a similar job in 'owl_dma_terminate_pchan()'. Therefore, this patch substitutes 'pchan->lock' with 'od->lock' and removes the 'lock' attribute in 'owl_dma_pchan' struct. Fixes: 47e20577c24d ("dmaengine: Add Actions Semi Owl family S900 DMA driver") Signed-off-by: Cristian Ciocaltea Reviewed-by: Manivannan Sadhasivam Acked-by: Andreas Färber --- Changes in v4: * Change patch title from 'dma: actions: Fix lockdep splat for owl-dma' to 'dmaengine: owl: Use correct lock in owl_dma_get_pchan()' * Add Fixes and Acked-by tags in the commit message Changes in v3: * Get rid of the kerneldoc comment for the removed struct attribute * Add the Reviewed-by tag in the commit message Changes in v2: * Improve the fix as suggested by Manivannan Sadhasivam: substitute 'pchan->lock' with 'od->lock' and get rid of the 'lock' attribute in 'owl_dma_pchan' struct * Update the commit message to reflect the changes drivers/dma/owl-dma.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/drivers/dma/owl-dma.c b/drivers/dma/owl-dma.c index c683051257fd..66ef70b00ec0 100644 --- a/drivers/dma/owl-dma.c +++ b/drivers/dma/owl-dma.c @@ -175,13 +175,11 @@ struct owl_dma_txd { * @id: physical index to this channel * @base: virtual memory base for the dma channel * @vchan: the virtual channel currently being served by this physical channel - * @lock: a lock to use when altering an instance of this struct */ struct owl_dma_pchan { u32 id; void __iomem *base; struct owl_dma_vchan *vchan; - spinlock_t lock; }; /** @@ -437,14 +435,14 @@ static struct owl_dma_pchan *owl_dma_get_pchan(struct owl_dma *od, for (i = 0; i < od->nr_pchans; i++) { pchan = &od->pchans[i]; - spin_lock_irqsave(&pchan->lock, flags); + spin_lock_irqsave(&od->lock, flags); if (!pchan->vchan) { pchan->vchan = vchan; - spin_unlock_irqrestore(&pchan->lock, flags); + spin_unlock_irqrestore(&od->lock, flags); break; } - spin_unlock_irqrestore(&pchan->lock, flags); + spin_unlock_irqrestore(&od->lock, flags); } return pchan; -- 2.26.2