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=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, T_DKIMWL_WL_HIGH,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 E07BDC004C9 for ; Tue, 7 May 2019 06:03:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A47D7205C9 for ; Tue, 7 May 2019 06:03:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557209008; bh=2hlKV15dkf6OVVVvZVumgaT6f7V2OIqq3kDJNscJRKQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Qm29tWYyqJFBr5/4gFGFksLYozM4ThabjecnW0fROWgFg1r6SS4SR0kxkXloVcvCW EhTSSDTE8Jzh0WZesFa32scRycsrapE9E4e1z9VJvXIMoBJpVsbjarOKjuCXua2Q5X o6pMV9sOCffId7pvkxAextx12OOpR2T3mib+Yykg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727109AbfEGGD1 (ORCPT ); Tue, 7 May 2019 02:03:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:55152 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727703AbfEGFfH (ORCPT ); Tue, 7 May 2019 01:35:07 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 39F9020C01; Tue, 7 May 2019 05:35:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557207307; bh=2hlKV15dkf6OVVVvZVumgaT6f7V2OIqq3kDJNscJRKQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MQMsMX5TCfjXTKlSJp7jh6eGTExqJfB7Pzy3vtYzw1FQLLzYVYRLjdVFcOdfDbecL ykeum5fLAMlVpCPXrPmMm9cihWkNWGt7WtfMRrPviL6JuYtYJ6tDNXrl/p+EurK6xZ WexRM+1DvXqhSzDJgLduUkZPAhbcQ+FXPHdWRoNc= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Stefan Wahren , Aaro Koskinen , Vinod Koul , Sasha Levin , dmaengine@vger.kernel.org Subject: [PATCH AUTOSEL 5.0 76/99] dmaengine: bcm2835: Avoid GFP_KERNEL in device_prep_slave_sg Date: Tue, 7 May 2019 01:32:10 -0400 Message-Id: <20190507053235.29900-76-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190507053235.29900-1-sashal@kernel.org> References: <20190507053235.29900-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Stefan Wahren [ Upstream commit f147384774a7b24dda4783a3dcd61af272757ea8 ] The commit af19b7ce76ba ("mmc: bcm2835: Avoid possible races on data requests") introduces a possible circular locking dependency, which is triggered by swapping to the sdhost interface. So instead of reintroduce the race condition again, we could also avoid this situation by using GFP_NOWAIT for the allocation of the DMA buffer descriptors. Reported-by: Aaro Koskinen Signed-off-by: Stefan Wahren Fixes: af19b7ce76ba ("mmc: bcm2835: Avoid possible races on data requests") Link: http://lists.infradead.org/pipermail/linux-rpi-kernel/2019-March/008615.html Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin --- drivers/dma/bcm2835-dma.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c index ae10f5614f95..bf5119203637 100644 --- a/drivers/dma/bcm2835-dma.c +++ b/drivers/dma/bcm2835-dma.c @@ -674,7 +674,7 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_slave_sg( d = bcm2835_dma_create_cb_chain(chan, direction, false, info, extra, frames, src, dst, 0, 0, - GFP_KERNEL); + GFP_NOWAIT); if (!d) return NULL; -- 2.20.1