From owner-freebsd-arm@FreeBSD.ORG Fri Oct 25 22:01:06 2013 Return-Path: Delivered-To: freebsd-arm@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTP id 8AB17E80 for ; Fri, 25 Oct 2013 22:01:06 +0000 (UTC) (envelope-from ian@FreeBSD.org) Received: from mho-02-ewr.mailhop.org (mho-02-ewr.mailhop.org [204.13.248.72]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 4C91D24FB for ; Fri, 25 Oct 2013 22:01:06 +0000 (UTC) Received: from c-24-8-230-52.hsd1.co.comcast.net ([24.8.230.52] helo=damnhippie.dyndns.org) by mho-02-ewr.mailhop.org with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.72) (envelope-from ) id 1VZpRJ-000AXb-9m; Fri, 25 Oct 2013 22:01:05 +0000 Received: from [172.22.42.240] (revolution.hippie.lan [172.22.42.240]) by damnhippie.dyndns.org (8.14.3/8.14.3) with ESMTP id r9PM13WE047127; Fri, 25 Oct 2013 16:01:03 -0600 (MDT) (envelope-from ian@FreeBSD.org) X-Mail-Handler: Dyn Standard SMTP by Dyn X-Originating-IP: 24.8.230.52 X-Report-Abuse-To: abuse@dyndns.com (see http://www.dyndns.com/services/sendlabs/outbound_abuse.html for abuse reporting information) X-MHO-User: U2FsdGVkX1/5D4aY0JIqcZtfPv3omr/I Subject: Re: Fwd: Dreamplug stable/10 usb - sd file transfer corruption error - cache related? From: Ian Lepore To: Steven Lee In-Reply-To: References: <1382734990.1170.132.camel@revolution.hippie.lan> Content-Type: text/plain; charset="us-ascii" Date: Fri, 25 Oct 2013 16:01:02 -0600 Message-ID: <1382738462.1170.153.camel@revolution.hippie.lan> Mime-Version: 1.0 X-Mailer: Evolution 2.32.1 FreeBSD GNOME Team Port Content-Transfer-Encoding: 7bit Cc: freebsd-arm@FreeBSD.org X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Porting FreeBSD to the StrongARM Processor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 25 Oct 2013 22:01:06 -0000 That old advice was based on bugs in old code that has been fixed. I've just been double-checking that the various fixes are in 10 (some of them were things I submitted a PR for before I became a committer). I'm not sure about the usb driver, but there have been big changes in the dma cache coherency code between 9 and 10, although much of that is the fixes I was alluding to. Basically what you're doing is a usb->usb copy, I'll see if I can recreate the corruption on my dreamplug here the same way. -- Ian On Fri, 2013-10-25 at 14:38 -0700, Steven Lee wrote: > ---------- Forwarded message ---------- > From: Steven Lee > Date: Fri, Oct 25, 2013 at 2:37 PM > Subject: Re: Dreamplug stable/10 usb - sd file transfer corruption error - > cache related? > To: Ian Lepore > > > Ian, thanks for your reply. > > I am using the DREAMPLUG-1001 stock kernel config, and you are right the > internal sd card shows up as a usb device, /dev/da0. > > As I mentioned, I tried modifying pmap.c as per one of your suggestions to > an earlier poster / problem, but it didn't seem to help the issue. I > changed the pmap_pte_init_arm10() function to look like the > pmap_pte_init_arm9() function. > > Any other thoughts about things to try? Since it seems like this is a > regression between 9 and 10, are you aware of any specific cache related > changes to the usb driver between the branches? > > - Steve > > > On Fri, Oct 25, 2013 at 2:03 PM, Ian Lepore wrote: > > > On Fri, 2013-10-25 at 13:37 -0700, Steven Lee wrote: > > > Hello, > > > > > > In the process of upgrading my Dreamplug from the stable/9 branch to the > > > stable/10 branch, I have run into a fairly > > > significant file corruption problem. The steps that create this problem > > > are as follows: > > > > > > 1. Cross-compile the kernel and buildworld from the stable/10 branch on a > > > separate host. > > > 2. Install the kernel and installworld on a usb stick drive > > > 3. Boot the Dreamplug from the usb drive > > > > > > There are no problems that show up to this point, the Dreamplug boots > > with > > > no errors. > > > > > > 4. Copy the kernel from the usb drive to the internal sd card > > > 5. Copy the root filesystem from the usb drive to the internal sd card > > > using (dump | restore) > > > > > > It is at step 5 that the error manifests itself, as I found that > > > approximately 20 shell scripts in the /etc/rc.d directory > > > had been randomly corrupted with strings of null characters (in groups of > > > 32). I assume that the rest of the file system > > > was compromised in a similar fashion. The bug is repeatable, however the > > > corruption is somewhat random, so > > > each time different files are corrupted in different places. > > > > > > When I followed the exact same steps from the stable/9 branch, the > > problem > > > did not occur, so there is clearly some > > > type of regression error between the 9 and 10 branches. > > > > > > After searching through the arm mailing list, I attempted to work around > > > the problem by: > > > - mounting the file systems with -o noclusterr -o noclusterrw > > > - mounting the file systems with -o sync > > > - as per comments on bug arm/158950, attempted to modify the pmap.c > > > functions to change the cache from > > > write-back mode to write-through mode > > > > > > but all of these attempts were ineffective. > > > > > > Given that I am relatively new to FreeBSD, I was hoping to get any > > insights > > > as to any next steps that might make > > > sense in terms of either working around the problem, narrowing down the > > > bug, or any obvious rookie mistakes I > > > am making before I give up and revert back to the 9 branch. > > > > > > Thanks for your help! > > > > > > Regards, > > > > On my dreamplug (model 1001) both the internal and external sd cards are > > actually usb devices (they show up as /dev/da0 and da1, not mmcsd0/1). > > I'm not sure if that's true on all models or not. > > > > Are you using the stock kernel config (DREAMPLUG-1001)? If not, have > > you got "option USB_HOST_ALIGN=32" in your kernel config? > > > > Corruption in 32 byte chunks is almost always partial cacheline flush > > problems, but I haven't seen that happen on dreamplug for a long time > > (and when I did see it, it was with a sata drive). > > > > -- Ian > > > > > _______________________________________________ > freebsd-arm@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-arm > To unsubscribe, send any mail to "freebsd-arm-unsubscribe@freebsd.org"