Date: Fri, 25 Oct 2013 14:38:24 -0700 From: Steven Lee <ssl.qlt@gmail.com> To: freebsd-arm@freebsd.org Subject: Fwd: Dreamplug stable/10 usb - sd file transfer corruption error - cache related? Message-ID: <CALD1=P=H0PwDh%2B2ix9RkszCuOsv8ucmk=8pSYYRwN__i0veSZw@mail.gmail.com> In-Reply-To: <CALD1=PkqJAmwzfq4Go_zQrc7nVMMzC=B%2BpTvT9rnCFkQ7rTJew@mail.gmail.com> References: <CALD1=P=gWosQsTTYt=hpkasP8y1rH3oH6y0n-y=APP_X0S%2BYFQ@mail.gmail.com> <1382734990.1170.132.camel@revolution.hippie.lan> <CALD1=PkqJAmwzfq4Go_zQrc7nVMMzC=B%2BpTvT9rnCFkQ7rTJew@mail.gmail.com>
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---------- Forwarded message ---------- From: Steven Lee <ssl.qlt@gmail.com> 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@freebsd.org> 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 <ian@freebsd.org> 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 > >
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