From mboxrd@z Thu Jan 1 00:00:00 1970 From: Aaron Lu Subject: SDIO driver return -ENOSYS behaviour change? Date: Thu, 27 Feb 2014 17:10:48 +0800 Message-ID: <530F0118.2010501@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mga01.intel.com ([192.55.52.88]:49536 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750844AbaB0JK7 (ORCPT ); Thu, 27 Feb 2014 04:10:59 -0500 Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Ulf Hansson Cc: NeilBrown , "linux-mmc@vger.kernel.org" Hi Ulf, I was tracking some SDIO suspend problem and came across this. As Neil mentioned here: http://lkml.org/lkml/2012/3/25/20 Quote: " SDIO (and possible MMC in general) has a protocol where the suspend method can return -ENOSYS and this means "There is no point in suspending, just turn me off". " It seems that the following commit: commit 810caddba42a54fe5db4e2664757a9a334ba359c Author: Ulf Hansson Date: Mon Jun 10 17:03:37 2013 +0200 mmc: core: Validate suspend prerequisites for SDIO at SUSPEND_PREPARE Changed this behaviour? For example, the libertas SDIO driver's suspend callback still returns -ENOSYS and before this commit, that error code will result in the SDIO device being removed; after this commit, that would result in an error code returned to PM core and a failure in system suspend. I'm not sure if I understand this correctly as I do not have any SDIO card to test. Can you please take a look at this? If this is indeed the case, do we need to maintain this behaviour? I need to know this answer as that would affect the way I'm going to solve my problem. Thanks.