From patchwork Tue Sep 15 20:45:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jaegeuk Kim X-Patchwork-Id: 11777693 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 19A40618 for ; Tue, 15 Sep 2020 20:52:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 000372080C for ; Tue, 15 Sep 2020 20:52:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600203164; bh=biBRsrW4Fs+Y3FfatFGMejxQwq4kpwq0ahfzBoNIGAM=; h=From:To:Cc:Subject:Date:List-ID:From; b=1E6oZrdw8bbYkXgXYdFvT+JNM6JXrsck6T89rF6SL6F6WafxvxMDyseZMrmeF9B/H m6nFyFoavqfpy0qrAepi/7C95eDUhPA+v3awxA+NB6qAyio1DoMXItUShQ4dAElRmV r4cea348OshbQYAA2UuZBcKXbWhMKA74jdT8cwHE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728047AbgIOUqq (ORCPT ); Tue, 15 Sep 2020 16:46:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:42646 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726454AbgIOUqg (ORCPT ); Tue, 15 Sep 2020 16:46:36 -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 3A4F120809; Tue, 15 Sep 2020 20:46:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600202796; bh=biBRsrW4Fs+Y3FfatFGMejxQwq4kpwq0ahfzBoNIGAM=; h=From:To:Cc:Subject:Date:From; b=TcTPD5CjNScvnACas/DuxQfwIjEVgKejo6dLSYhm84AuwpnT25q9TzTumsFBiJbCq 0ltWf08wjOzM7tYCAoEJ6QMl1yuBlSB9OZ/ca/xZNMSyB0B3cLS6X5Pil/J2KyoWpB /+pt0YNu3CMzHZHBvVJXIxUlgKqGHqzwXplGgKCU= 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 Subject: [PATCH 1/6] scsi: ufs: atomic update for clkgating_enable Date: Tue, 15 Sep 2020 13:45:27 -0700 Message-Id: <20200915204532.1672300-1-jaegeuk@kernel.org> X-Mailer: git-send-email 2.28.0.618.gf4bc123cb7-goog MIME-Version: 1.0 Sender: linux-scsi-owner@vger.kernel.org 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 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; }