MMC1 keeps getting set to read-only...
 

For some reason, my N800 keeps setting (or just thinking that) my MMC1 card (removable SD) to read-only. But, when I Get Info on the card, the checkbox is not checked. (And, since it is read-only, I can't even check/uncheck the checkbox).

This has happened on two cards so far with no action on my part -- it just turns out to be read-only at some point.

Has anyone ever experienced this?

Also, I have been given a few ways to try to change the card's filesystem back to read/write, but I was wondering if anyone here has the "right" way to do this.

Thanks,
Tim

Re: MMC1 keeps getting set to read-only...
 

I can't help, but I can commiserate. It happens to me all the time. And it seems intermittent. When the N800 claims the card is read-only, I have been able to connect to a PC via USB and write to it.

Wierd!

Re: MMC1 keeps getting set to read-only...
 

When cards go to read-only it's usually because of some physical problem with the card.

Re: MMC1 keeps getting set to read-only...
 

my SDHC 8 gig card seems to have this issue, both with the old 2007 and new 2007, both with modified kernel.....
opening and closing the little door on the front seems to change things...

Doesn't matter though, I put my (hundreds of hours of) music on via USB and use the 4 gig non-sdhc in the internal slot to save stuff....

For me, it is definetely an SDHC issue (I think).
Often, the physical switch on my SD card (the SDHC card), when switched to "read only" works for saving, and when switched to "write" does not....

who knows....

check the external switch on the actual card though.

DCarter

Re: MMC1 keeps getting set to read-only...
 

No, the switch is fine.

And, as I said, this has happened with two cards -- both good before placing in the MMC1 (removable) slot.

But, this being said... Windows sees the card as read/write -- and has no trouble using the card.

This is a 4GB card, though... Ugh. Any other suggestions?

Tim

Re: MMC1 keeps getting set to read-only...
 

Because Nokia explicitly stated that 2gig cards were supported,
and made no mention, claim, or guarantee that a 4gig card would work,

and because I can save to all my cards (big, small, SDHC or not)
via terminal commands,

I have to assume this is a "File Manager" problem,
that Maemo software app. is the weak link here.

DCarter

Re: MMC1 keeps getting set to read-only...
 

My 770 with the unofficial OS 2007 shows a similar problem:

I cannot modify the filesystem on the MMC with the filemanager anymore.
The card is OK (fscked already), and it happens to every MMC inserted into the
770. The funny thing is that all applications on the 770 can read and write the card. Only the filemanager keeps telling that it's not writable.

I guess it's time to reflash the device... :(

Re: MMC1 keeps getting set to read-only...
 

Interesting. Ok, makes sense.

-T.

Re: MMC1 keeps getting set to read-only...
 

Sorry to put a fly in the ointment -- but my card is a 1 GB RS-MMC.

-F

Re: MMC1 keeps getting set to read-only...
 

And you have the same issue?

Does the card still work on a PC?

-T.

Re: MMC1 keeps getting set to read-only...
 

Yes...

-F

Re: MMC1 keeps getting set to read-only...
 

I'm going to add this thread to the bug tracker and see what I find out.

Tim

Re: MMC1 keeps getting set to read-only...
 

I've had cards that refuse to mount in the N800, the info bubble says "card is corrupt" but when I pop the card into a Windows XP card reader XP mounts it just fine with no hint of corruption. Interestingly, if I then insert the card back into the N800 the card is mounted without a problem.

It's as if something is being "corrupted" in the vfat filesystem which trips up the N800, and Windows will reset the "corruption" without a murmur. This suggests the N800/Linux vfat implementation is perhaps incomplete or over sensitive to some benign feature in the filesystem.

Re: MMC1 keeps getting set to read-only...
 

I have been suffering this memory card corruption issue too. Now lately my 4GB SD card that was working relatively good has become unusable.

I suspect the card is now bad because it does corrupt even when using with a PC USB card reader. I just copied a bunch of files to it and after that, without removing the card, I run disk check... and it found lots of errors and lost file fragments. Before it worked fine.

The question is that could it be that it has just wore out? I used to use that card with N800 and I had lots of MaemoMapper map files stored on it. I had formatted the card about 5 times total and copied the map files (over 20 thousand individual files) to it after each format... What I think that in that kind of use the FAT table (located in some certain memory address range) gets written each time any file is copied or deleted from the card. Once this is done some "tens of thousands times" it exceeds the life time of the memory cells located in the FAT table area.

This is just speculation from my part, but if there is someone who knows exactly how the FAT table updates are handled by the file system. Are all or some of those memory cells written each time any file change has happened?

Before I know for sure I'm not very confident starting to copy my map files to my new 8GB card... and destroy it... :eek: I'd rather use smaller and cheap card that I can afford to replace every once in a while... and use the big card for big and not frequently updated files only.

Re: MMC1 keeps getting set to read-only...
 

I did some research and looks like the FAT table flash wear out is very possible...
http://ej.iop.org/links/rSET_iM8K/Dh...nf6_48_248.pdf

Unless there is some built in wear out mechanism, the flash can easily wear out if the FAT table is updated frequently, such as when using Maemo Mapper.

Anybody have any more insight? Do (some/all?) SD cards have this wear out (load balancing) mechanism built in hardware, or is it the responsibility of SD card controller? Does N800 memory card controller has such code?

Re: MMC1 keeps getting set to read-only...
 

I'm pretty sure most (if not all) flash memory cards have built-in wear levelling these days - it's a feature built into the card itself so the controller/OS doesn't have to concern itself with this function, although some filesystems (such as jffs2 which is the filesystem used for the flash memory built into the 770/N800) are optimised to minimise updates where possible.

There is a discussion in bugzilla where a Nokia claims the flash memory in the device should be good for 30+ years assuming it is used every day. With a filesystem that is not optimised for flash it might be possible to assume that the lifetime of the card will be less than 30 years, but probably longer than a couple of years (which would be fine with me). I'll try and find a link...

EDIT: Bug #598 discusses wear levelling.

EDIT2: This wiki entry claims that SD and CF cards have built-in wear-levelling and error correction circuitry... no mention of MMC though. :(

Re: MMC1 keeps getting set to read-only...
 

FYI, all of my issues stemmed from brand new cards.

-T.

Re: MMC1 keeps getting set to read-only...
 

The last post in this thread appears old so maybe these problems are no longer occurring for most, but here's a recent similar experience. I've a Nokia N800 with the 128 mbyte card that came with it and a 6 gig SanDisk microSDHC. I had flashed OS2008 to it and was enjoying it when suddenly both cards borked with the same symptom. Apparently read-only without the ability to set or clear the read-only flag. These cards could be written on another machine with a USB SD card reader.

Taking another post advice I backed up a the 6 gig card and reformatted it with the N800. After that it said it was corrupt. The offered repair did not fix it. A reformat did not work. I removed it to another computer and it appeared fine. I reformatted it and wrote a bunch of files to it but it again said it was corrupt in the N800.

I finally REFLASHED 0S2008 and now all seems well again, the cards are again readable. Hope this was an isolated incident.

..prollymolly

Re: MMC1 keeps getting set to read-only...
 

Interesting. I just had a similar problem the other day with 'read-only' memory memory message for the card in the internal slot. I have a reg 4g sd in there.
By pure newb happenstance, I disabled the 'virtual memory' which I had at 128mbs and suddenly it was not an issue anymore.

Might that be a factor? Virtual memory?

Just my two cents worth.

Re: MMC1 keeps getting set to read-only...
 

Hello, sorry to be a newby, but I have excatly same problem with my 1gb sd in internal slot. Except that I have no extra virtual memory on my memory cards...

Re: MMC1 keeps getting set to read-only...
 

what worked for me was to open the folder in 2 different windows and select uncheck read, hit apply, and stay on the properties screen, then go to the second window and put files on it from there.

Re: MMC1 keeps getting set to read-only...
 

Interestingly, this happened to me with the N900 last week.

I'm planning to flash to 1.2009.42-11.002 today, but the problem is that I cannot make backups as long as the cards are read-only...

Re: MMC1 keeps getting set to read-only...
 

Any idea on how to resolve this?

Re: MMC1 keeps getting set to read-only...
 

I had the same error, only way I was able to resolve was by reformatting mmc1. I backed up my data before I followed these steps:

http://talk.maemo.org/showthread.php...081#post452081

Re: MMC1 keeps getting set to read-only...
 

You could try to do fsck to the filesystem on mmc1,

umount <filesystem>
fsck <filesystem>
mount <filesystem>

I had a dirty filesystem on Mydocs on my n900 and do a fsck fixed it.

Re: MMC1 keeps getting set to read-only...
 

out of topic, but i have the same issue, but on my n900. would this issue with n800 the same with n900? thanks'

it kinda annoys me coz i need to plug it on my win7 laptop and do a "scan and fix" option every time this happens.

EDIT: bergie posted above, ouch!

Re: MMC1 keeps getting set to read-only...
 

I have same issue. The problem came a few days ago and now it occurs every time I connect N900 through USB. This is kind of stupid 'cause I can't event use Backup tool to create a backup before formatting the partition. I wish I could show the screenshot with the damn error message, but I can't even save it.

Re: MMC1 keeps getting set to read-only...
 

Managed to fix it with:
and yeah, here is it:
http://i33.tinypic.com/z0t2h.png

Re: MMC1 keeps getting set to read-only...
 

[QUOTE=sph;787819]Managed to fix it with:

this fix the read-only problem right? not formating? thanks :)

Re: MMC1 keeps getting set to read-only...
 

yes, it will fix errors without formating.

Re: MMC1 keeps getting set to read-only...
 

hi!

after doing a fix for emmc or mmc1 that became read-only, .REC files appeared on my drives. can those be deleted without any ill effects?

nokia n900

thanks.