From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nguyen Viet Dung Subject: Re: [bug] kernel panic if writting data to mmc after suspendding Date: Tue, 22 Dec 2015 12:16:17 +0900 Message-ID: <5678C081.5090001@jinso.co.jp> References: <566A21D2.4080009@jinso.co.jp> <566E2AC0.8060800@jinso.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from www1246.sakura.ne.jp ([219.94.162.56]:56005 "EHLO www1246.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750985AbbLVDQU (ORCPT ); Mon, 21 Dec 2015 22:16:20 -0500 In-Reply-To: Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Ulf Hansson , Geert Uytterhoeven Cc: Linux-sh list , Linux MMC List , "ltsi-dev@lists.linuxfoundation.org" , =?UTF-8?B?U2ltb24g44GV44KT?= , Geert Uytterhoeven , =?UTF-8?B?U+mWizEyL+WdguaIuFND?= , "Shimoda, Yoshihiro" , =?UTF-8?B?TWFnbnVzIOOBleOCkw==?= , Hisao Munakata Hi Geert Thank for your reply. On 2015=E5=B9=B412=E6=9C=8818=E6=97=A5 19:27, Ulf Hansson wrote: > On 18 December 2015 at 10:33, Geert Uytterhoeven wrote: >> Hi Dung-san, >> >> CC Ulf >> >> On Mon, Dec 14, 2015 at 3:34 AM, Nguyen Viet Dung wrote: >>> While is testting LTSI-v4.1.13-rc1, we have found the following the= failure >>> of mmcif. >>> 1. mount mmc block >>> 2. write data to mmc block >>> 3. suspend/resume >>> 4. write data to mmc block one again =3D> happen kernel panic >>> (Probability in this test procedure is 100%) >>> >>> We have used git bisect to find cause of failure in LTS-v4.1.13 to >>> LTSI-v4.1.13-rc1 >>> and have found commit which cause failure. >>> (On LTS-v4.1.13 has not this failure) >>> drivers: sh: Disable PM runtime for multi-platform ARM with genpd >>> commit :cbc41d0a761bffb3166a413a3c77100a737c0cd7 >> That means there's a bug in Runtime PM handling of the sh_mmcif driv= er, or >> in the MMC subsystem. >> >> Usually such bugs cause a kernel hang on register access, not a NULL= pointer >> dereference, though. > Agree! > > I doubt the bisected commit is where the *real* issue is. Looking int= o > the details for how system PM and runtime PM is deployed in sh_mmcif, > I believe some improvements are needed. > > Actually, I made an attempt to modernize the PM code for sh_mmcif a w= hile ago. > http://marc.info/?l=3Dlinux-mmc&m=3D138245085523815&w=3D2 > > Whether that fixes the problem reported here, I have no idea. Althoug= h > if not, it should move the code to a position where it becomes easier > to properly fix this issue. > > I am willing to help and rebase that patchset, but I require help in > testing since I haven't been able to get a hold of a HW. Can I count > on that? Yes , I can help you test. If you have rebased patchset, phease tell me. Best regards, Nguyen Viet Dung