Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753117AbdFSSfl (ORCPT + 2 others); Mon, 19 Jun 2017 14:35:41 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:52149 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753086AbdFSSfi (ORCPT ); Mon, 19 Jun 2017 14:35:38 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net Cc: Adrian Hunter , Ulf Hansson , Jiri Slaby , Willy Tarreau Subject: [PATCH 3.10 200/268] mmc: sdhci: Do not disable interrupts while waiting for clock Date: Mon, 19 Jun 2017 20:31:39 +0200 Message-Id: <1497897167-14556-201-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1497897167-14556-1-git-send-email-w@1wt.eu> References: <1497897167-14556-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: From: Adrian Hunter commit e2ebfb2142acefecc2496e71360f50d25726040b upstream. 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 Signed-off-by: Ulf Hansson Tested-by: Ludovic Desroches Signed-off-by: Jiri Slaby Signed-off-by: Willy Tarreau --- 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 836e2ac..16d7f93 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -1220,7 +1220,9 @@ clock_set: return; } timeout--; - mdelay(1); + spin_unlock_irq(&host->lock); + usleep_range(900, 1100); + spin_lock_irq(&host->lock); } clk |= SDHCI_CLOCK_CARD_EN; -- 2.8.0.rc2.1.gbe9624a