From patchwork Mon Oct 5 22:36:32 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jaegeuk Kim X-Patchwork-Id: 11817829 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D8B076CB for ; Mon, 5 Oct 2020 22:36:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BF21320796 for ; Mon, 5 Oct 2020 22:36:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601937404; bh=TKL2MsscyE/vIAfUltMtJXP6uFHSkqzpM4DPoVgZ1Tw=; h=From:To:Cc:Subject:Date:List-ID:From; b=QIhurMufHodT57FjuvCsX+fmXbA9W1PBLisJSHPyPExcYkT5RlT9i0u+DY+Xh1+9O aWAJ9G3moAbc0dAYGTFtDpBJKjM4H7Fcb+hxEdxnkEl8TQFdsDJMl7J5FBIEW0cuXZ zaE+SkNITq9V33PKTfPyC227r0M4hpM6NROMOwns= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726604AbgJEWgh (ORCPT ); Mon, 5 Oct 2020 18:36:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:56780 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725917AbgJEWgh (ORCPT ); Mon, 5 Oct 2020 18:36:37 -0400 Received: from localhost (unknown [104.132.1.66]) (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 2D02B2078A; Mon, 5 Oct 2020 22:36:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601937397; bh=TKL2MsscyE/vIAfUltMtJXP6uFHSkqzpM4DPoVgZ1Tw=; h=From:To:Cc:Subject:Date:From; b=zDlMHnRqW36LuoFxud7eaHvZumJlikFASkuU8WD3CCiGHGy2eNkDGzi9gV9xYQLVN BL0e8uFjmLNklLV5OkcXVhp6Gz6Cj6YSZbLzFldclDzBYe78vrrjjTzrxmIGBmlgsY 35XeRlJ84TbKfygbL7ovaaXZfSuiPnxmfHqHXagI= From: Jaegeuk Kim To: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, kernel-team@android.com Cc: Jaegeuk Kim , Alim Akhtar , Avri Altman , Can Guo Subject: [PATCH 1/4] scsi: ufs: atomic update for clkgating_enable Date: Mon, 5 Oct 2020 15:36:32 -0700 Message-Id: <20201005223635.2922805-1-jaegeuk@kernel.org> X-Mailer: git-send-email 2.28.0.806.g8561365e88-goog MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org From: Jaegeuk Kim When giving a stress test which enables/disables clkgating, we hit device timeout sometimes. This patch avoids subtle racy condition to address it. Cc: Alim Akhtar Cc: Avri Altman Cc: Can Guo Signed-off-by: Jaegeuk Kim --- drivers/scsi/ufs/ufshcd.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 1d157ff58d817..d929c3d1e58cc 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -1791,19 +1791,19 @@ static ssize_t ufshcd_clkgate_enable_store(struct device *dev, return -EINVAL; value = !!value; + + spin_lock_irqsave(hba->host->host_lock, flags); if (value == hba->clk_gating.is_enabled) goto out; - if (value) { - ufshcd_release(hba); - } else { - spin_lock_irqsave(hba->host->host_lock, flags); + if (value) + hba->clk_gating.active_reqs--; + else hba->clk_gating.active_reqs++; - spin_unlock_irqrestore(hba->host->host_lock, flags); - } hba->clk_gating.is_enabled = value; out: + spin_unlock_irqrestore(hba->host->host_lock, flags); return count; }