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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 EB8EDC55186 for ; Wed, 22 Apr 2020 10:05:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C518D2076C for ; Wed, 22 Apr 2020 10:05:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587549945; bh=A2UMnMA1ZND4qAGm1dxuSMBHu5SS4sAQGoBYRUZdWV0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=FAaJHYhwXXvETksXBT8UFGzw74IPp1IX+DQjkgYmNYoXfQd6kZ7M47/uPeY1UxDaI LFhlV4MI97ox+tSPNUVSFWvRNiNYgehBV9/jwauAa68vPuTjjmQtrswzEKS+nyrjmg 9IHGgts+Tdk0zbE42OB/xaX13OlcVgytHSEsE7HM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728224AbgDVKFp (ORCPT ); Wed, 22 Apr 2020 06:05:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:57014 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728206AbgDVKFk (ORCPT ); Wed, 22 Apr 2020 06:05:40 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0611820575; Wed, 22 Apr 2020 10:05:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587549940; bh=A2UMnMA1ZND4qAGm1dxuSMBHu5SS4sAQGoBYRUZdWV0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ujhdazpmTuRHFd4r/8bQDGUCNIN1FBln58n56/esmTK9ND6m9dakKQ0mjXc/ZVtAu 1bu7l7VqVavLGsYuisbmLSaQu1L6QJ8I3WllDw8qXDoLSGjjVBsd7hzs5lOO+mJy2X jUKOiko1YbVVoZMVdhpS40Z7p61bWxmcrM1y29Rk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hongwu Su , Asutosh Das , Bean Huo , Stanley Chu , Can Guo , "Martin K. Petersen" Subject: [PATCH 4.9 070/125] scsi: ufs: Fix ufshcd_hold() caused scheduling while atomic Date: Wed, 22 Apr 2020 11:56:27 +0200 Message-Id: <20200422095044.605451973@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200422095032.909124119@linuxfoundation.org> References: <20200422095032.909124119@linuxfoundation.org> User-Agent: quilt/0.66 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 From: Can Guo commit c63d6099a7959ecc919b2549dc6b71f53521f819 upstream. The async version of ufshcd_hold(async == true), which is only called in queuecommand path as for now, is expected to work in atomic context, thus it should not sleep or schedule out. When it runs into the condition that clocks are ON but link is still in hibern8 state, it should bail out without flushing the clock ungate work. Fixes: f2a785ac2312 ("scsi: ufshcd: Fix race between clk scaling and ungate work") Link: https://lore.kernel.org/r/1581392451-28743-6-git-send-email-cang@codeaurora.org Reviewed-by: Hongwu Su Reviewed-by: Asutosh Das Reviewed-by: Bean Huo Reviewed-by: Stanley Chu Signed-off-by: Can Guo Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/ufs/ufshcd.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -682,6 +682,11 @@ start: */ if (ufshcd_can_hibern8_during_gating(hba) && ufshcd_is_link_hibern8(hba)) { + if (async) { + rc = -EAGAIN; + hba->clk_gating.active_reqs--; + break; + } spin_unlock_irqrestore(hba->host->host_lock, flags); flush_work(&hba->clk_gating.ungate_work); spin_lock_irqsave(hba->host->host_lock, flags);