From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Sun, 29 Jul 2018 11:41:31 +0200 From: Tomas Janousek To: Ming Lei Cc: Patrick Steinhardt , Jens Axboe , linux-block , Linux Kernel Mailing List Subject: Re: [PATCH] block: fix NPE when resuming SCSI devices using blk-mq Message-ID: <20180729094131.4kwuukzgfgtisgya@notes.lisk.in> References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 In-Reply-To: List-ID: Hi, On Fri, Jul 13, 2018 at 09:41:41PM +0800, Ming Lei wrote: > Now runtime PM is disabled for blk-mq/scsi_mq, not sure how this issue is > triggered on your machine. While Patrick did miss the following patch: * 765e40b675a9 ("block: disable runtime-pm for blk-mq"; July 2017). there is at least one other way to trigger it -- enable laptop-mode-tools or tlp which enable runtime-pm for all devices. The "disable runtime-pm for blk-mq" only disables it _by_default_, but doesn't prevent it from being enabled again from user-space, which it is unless one manually blacklists sd devices from runtime-pm enablement. It's bitten a few people already: https://github.com/rickysarraf/laptop-mode-tools/issues/123 (I found this thread because I'm also getting the NULL pointer dereference at 00000000000001a8 on resume from suspend.) -- Tomáš Janoušek, a.k.a. Pivník, a.k.a. Liskni_si, http://work.lisk.in/