From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nguyen Viet Dung Date: Thu, 04 Feb 2016 00:52:17 +0000 Subject: Re: [bug] kernel panic if writting data to mmc after suspendding Message-Id: <56B2A0C1.9050808@jinso.co.jp> List-Id: References: <566A21D2.4080009@jinso.co.jp> <566E2AC0.8060800@jinso.co.jp> <5678C081.5090001@jinso.co.jp> In-Reply-To: <5678C081.5090001@jinso.co.jp> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit To: Ulf Hansson , Geert Uytterhoeven , Linux MMC List Cc: Linux-sh list , "ltsi-dev@lists.linuxfoundation.org" , =?UTF-8?B?U2ltb24g44GV44KT?= , Geert Uytterhoeven , "Shimoda, Yoshihiro" , Hisao Munakata Hi Ulf I want to test this problem withc your patch. Please sent pacthset for me. I have checked below link but detail of patch haven't. Best regard, Nguyen Viet Dung On 2015年12月22日 12:16, Nguyen Viet Dung wrote: > Hi Geert > > Thank for your reply. > > On 2015年12月18日 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 => 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 >>> driver, 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 into >> 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 >> while ago. >> http://marc.info/?l=linux-mmc&m8245085523815&w=2 >> >> Whether that fixes the problem reported here, I have no idea. Although >> 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