Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754829AbdDJPtJ (ORCPT ); Mon, 10 Apr 2017 11:49:09 -0400 Received: from mx2.suse.de ([195.135.220.15]:38091 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754509AbdDJPei (ORCPT ); Mon, 10 Apr 2017 11:34:38 -0400 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Adrian Hunter , Ulf Hansson , Jiri Slaby Subject: [PATCH 3.12 093/142] mmc: sdhci: Do not disable interrupts while waiting for clock Date: Mon, 10 Apr 2017 17:32:54 +0200 Message-Id: <597590a08a087c2d795a840283203c4a431ea080.1491838390.git.jslaby@suse.cz> X-Mailer: git-send-email 2.12.2 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1505 Lines: 46 From: Adrian Hunter 3.12-stable review patch. If anyone has any objections, please let me know. =============== 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 --- 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 4e697ea67ae2..c3070ab2a05c 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -1232,7 +1232,9 @@ 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; -- 2.12.2