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chick
8 Posts |
 Posted - 06 Nov 2003 : 13:21:28
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Occasionally, our Bitsy-X board can no longer write to a particular CF card, although it can still read from the CF. This has happened twice, both times with SanDisk cards. The CF card can be still be read/written with a desktop PC card reader. Reformatting the card doesn't help.
Has anyone seen this before? |
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rwhaley
628 Posts |
Posted - 06 Nov 2003 : 13:41:15
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This hasn't been seen before.
Can you please provide more details:
Which socket are you using: PCMCIA or CF on the connector board?
What card model are you using? (Output from 'cardctl ident' would be good).
How are you mounting the card? Which partitions of the card are you mounting?
How are the partitions formatted? (Output from 'mount' would be good).
What commands or programs are you using when you try to write to the card?
What error messages or codes do you get when you try to write to the card?
How full is partition? (Output from 'df' would be good.)
Any other details that might be helpful would be appreciated.
Are you willing to lend the card to us so we can try to figure out why it's no longer working?
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akidder
1519 Posts |
Posted - 06 Nov 2003 : 13:45:52
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I haven't seen this issue, either. I agree with Robert that it would be helpful to have a card or two to test with here, especially if there's a way we can reproduce the issue reliably.
Let us know what will work for you.
-Drew |
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Renyi
26 Posts |
Posted - 18 May 2004 : 23:30:32
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It happened to our GM board (CE build 3.33) as well. When our program downloaded data to CF card, everything (create file, write data and close file)seemed OK, but sometimes there was just no file acturally generated.
One of our customers using our program in their kiosk machines also complained that they lost credit card transaction data sometimes. I checked their data files and figured that the problematic CF card actually generated a data file and even recorded some transactions, but all of a sudden it stopped writting.
The ugly thing here is that the CF card doesn't report any errors when it fails to write and this will cause our customer to lose money.
Does anybody have any idea? |
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akidder
1519 Posts |
Posted - 19 May 2004 : 13:42:11
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Thanks for your note, Renyi. Are you able to reproduce this condition at your facility? We have not seen this kind of behavior here, but we may not be using the system the same way you are.
The commonality between your issue, Renyi, and "chick's" is that you are both using Windows CE. However, chick is using .NET on the PXA255 BitsyX, while you are using 3.0 on the SA-1110 CPU. Both products use the SA-1111 for CF bus control.
The only issue we know about right now with CF cards is that some systems can't read cards that are formatted with Windows XP. That isn't the issue here. Is it possible that the system is turning off or going to sleep before the data could be flushed from the CF card's RAM buffer into its flash memory?
Your best bet for your application at this time is probably to implement a read-back function to confirm that the data you wrote can be read back. If you find a card that fails, ship us the card and a test application that shows the problem, and we'll be glad to investigate! |
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Renyi
26 Posts |
Posted - 19 May 2004 : 17:53:16
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Thanks for your quick reply, Andrew. Acturally that's what I plan to do to add a read-back function. But one more question here. At what point, does CF card flush data from RAM buffer into flash memory, does it flush data when I close the file?
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akidder
1519 Posts |
Posted - 20 May 2004 : 11:53:16
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Thanks, Renyi. I'm not aware of any disk caching that CE performs.
CompactFlash and other solid-state removable media achieve quick data transfers by placing the incoming data in buffers. This allows seemingly high data transfer rates for small data blocks (e.g. a photo) even though the underlying storage medium is the slower flash memory.
I'm not aware of any means for forcing a device to flush its cache; I susplect that the devices write the data into flash as quickly as they can.
If someone else has details about this "feature" of CF cards, please chime in!
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Renyi
26 Posts |
Posted - 22 Sep 2004 : 23:36:25
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Hi,
Our customer complained again. This time they lost transaction files after an OS error. Don't know what OS error. What happened is the machine popped up an error message box for some unknown reason, stayed intact for about 20s, then WDT kicked in, machine got reset, wait until reset finished, unpluged the CF card, checked it in PC and found transaction files missing.
The machine is running on GMaster CE build 3.40 I believe.
Anyone have similar experience? or any clues? |
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Renyi
26 Posts |
Posted - 23 Sep 2004 : 12:13:38
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Hi,
My guess is when some certain kinds of system errors happen, the CF card is left in an inconsistent state and at next bootup is formatted automatically by OS due to inconsistent state (corrupted state?). Is that possible? Does anybody know where to find detailed information about how CF card works? for example, when the device flush its cashe? |
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