From patchwork Mon Mar 20 17:50:29 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adrian Hunter X-Patchwork-Id: 9634963 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id A5F6C602D6 for ; Mon, 20 Mar 2017 18:18:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9DC20205AD for ; Mon, 20 Mar 2017 18:18:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 927B526D05; Mon, 20 Mar 2017 18:18:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 32E0E205AD for ; Mon, 20 Mar 2017 18:18:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756545AbdCTSSu (ORCPT ); Mon, 20 Mar 2017 14:18:50 -0400 Received: from mga01.intel.com ([192.55.52.88]:15128 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756528AbdCTR7j (ORCPT ); Mon, 20 Mar 2017 13:59:39 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=intel.com; i=@intel.com; q=dns/txt; s=intel; t=1490032778; x=1521568778; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=2c5uhq2+K3G5W5z9UiZyNBJJMJzA29UJF0oD3APy/tg=; b=itRj8CXE6EpMlrMbhaie22W8pxcy2Ngf+bWOJJpdsCmB2otXN4OC0PCb EobbZGwF5MH3C/H3BfEY8nngfsEdaw==; Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Mar 2017 10:56:34 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.36,195,1486454400"; d="scan'208";a="1124975091" Received: from ahunter-desktop.fi.intel.com ([10.237.72.168]) by fmsmga001.fm.intel.com with ESMTP; 20 Mar 2017 10:56:30 -0700 From: Adrian Hunter To: Ulf Hansson Cc: linux-mmc , Al Cooper , Jaedon Shin , Haibo Chen , Dong Aisheng , Shawn Lin , Douglas Anderson , Zach Brown , Ludovic Desroches , Jisheng Zhang , Yangbo Lu , Jaehoon Chung , Weijun Yang , Barry Song , Peter Griffin , Lee Jones , Jon Hunter , Harjani Ritesh Subject: [PATCH 01/25] mmc: sdhci: Do not disable interrupts while waiting for clock Date: Mon, 20 Mar 2017 19:50:29 +0200 Message-Id: <1490032253-6030-2-git-send-email-adrian.hunter@intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1490032253-6030-1-git-send-email-adrian.hunter@intel.com> References: <1490032253-6030-1-git-send-email-adrian.hunter@intel.com> Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Disabling interrupts for even a millisecond can cause problems for some devices. That can happen when sdhci changes clock frequency because it waits for the clock to become stable under a spin lock. The spin lock is not necessary here. Anything that is racing with changes to the I/O state is already broken. The mmc core already provides synchronization via "claiming" the host. Although the spin lock probably should be removed from the code paths that lead to this point, such a patch would touch too much code to be suitable for stable trees. Consequently, for this patch, just drop the spin lock while waiting. Signed-off-by: Adrian Hunter Cc: stable@vger.kernel.org --- drivers/mmc/host/sdhci.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 6fdd7a70f229..9c1a099afbbe 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -1362,7 +1362,9 @@ void sdhci_enable_clk(struct sdhci_host *host, u16 clk) return; } timeout--; - mdelay(1); + spin_unlock_irq(&host->lock); + usleep_range(900, 1100); + spin_lock_irq(&host->lock); } clk |= SDHCI_CLOCK_CARD_EN;