From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:51070 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932268AbdC1LGi (ORCPT ); Tue, 28 Mar 2017 07:06:38 -0400 Subject: Patch "mmc: sdhci: Do not disable interrupts while waiting for clock" has been added to the 4.4-stable tree To: adrian.hunter@intel.com, gregkh@linuxfoundation.org, ludovic.desroches@microchip.com, ulf.hansson@linaro.org Cc: , From: Date: Tue, 28 Mar 2017 13:05:25 +0200 Message-ID: <1490699125176249@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled mmc: sdhci: Do not disable interrupts while waiting for clock to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mmc-sdhci-do-not-disable-interrupts-while-waiting-for-clock.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From e2ebfb2142acefecc2496e71360f50d25726040b Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Mon, 20 Mar 2017 19:50:29 +0200 Subject: mmc: sdhci: Do not disable interrupts while waiting for clock 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: Greg Kroah-Hartman --- drivers/mmc/host/sdhci.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -1274,7 +1274,9 @@ 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; Patches currently in stable-queue which might be from adrian.hunter@intel.com are queue-4.4/mmc-sdhci-do-not-disable-interrupts-while-waiting-for-clock.patch