From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755764AbdC1MpV (ORCPT ); Tue, 28 Mar 2017 08:45:21 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:34010 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755707AbdC1MpQ (ORCPT ); Tue, 28 Mar 2017 08:45:16 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Adrian Hunter , Ulf Hansson , Ludovic Desroches Subject: [PATCH 4.9 60/88] mmc: sdhci-pci: Do not disable interrupts in sdhci_intel_set_power Date: Tue, 28 Mar 2017 14:31:15 +0200 Message-Id: <20170328122751.129584502@linuxfoundation.org> X-Mailer: git-send-email 2.12.1 In-Reply-To: <20170328122748.656530096@linuxfoundation.org> References: <20170328122748.656530096@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Adrian Hunter commit 027fb89e61054b4aedd962adb3e2003dec78a716 upstream. Disabling interrupts for even a millisecond can cause problems for some devices. That can happen when Intel host controllers wait for the present state to propagate. 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 Signed-off-by: Ulf Hansson Tested-by: Ludovic Desroches Signed-off-by: Greg Kroah-Hartman --- drivers/mmc/host/sdhci-pci-core.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/mmc/host/sdhci-pci-core.c +++ b/drivers/mmc/host/sdhci-pci-core.c @@ -412,6 +412,8 @@ static void sdhci_intel_set_power(struct if (mode == MMC_POWER_OFF) return; + spin_unlock_irq(&host->lock); + /* * Bus power might not enable after D3 -> D0 transition due to the * present state not yet having propagated. Retry for up to 2ms. @@ -424,6 +426,8 @@ static void sdhci_intel_set_power(struct reg |= SDHCI_POWER_ON; sdhci_writeb(host, reg, SDHCI_POWER_CONTROL); } + + spin_lock_irq(&host->lock); } static const struct sdhci_ops sdhci_intel_byt_ops = {