> We've been working on a project that uses the TS-7390 and we're finding a
> weird bug that is causing the SD card driver to get screwed up. I believe
> it's a bug in either the tsuart drivers or the tssdcard driver. I can
> reproduce the problem with a brand new SD card, after dd'ing the
> 512mbsd-latest.dd file from the TS FTP site to it (which contains the latest
> tsuart and tssdcard drivers).
>
> It seems that when reading simultaneously from ttts0 and the SD card, the SD
> card gets messed up and starts returning corrupt data whenever reading from
> it. The file system starts exhibiting strange behavior showing empty
> directories and incorrect file content, but the data on the card itself is
> fine once I reboot.
>
>
I am unconvinced by the stability of the sdcard driver.
I'm not sure about the 7350 - but on the TS7400 there is a design issue
(or rather lack of clarity): The port_b4 gpio line doubles up as the
dmaenable line for dma channel 0. This is undocumented - and caused a
problem with a board I designed. The issue arises when using dma
enabled on the driver and channel 0 is used.
The driver software for the 8 bit CPLD interfaces (7250 and 7400)
contain a busy wait loop in them to stop faulty signaling on them. Im
not sure about the 16 bit interfaces (e.g. the 73 series) - but there
may be an equivalent loop or a race condition in that loop in the driver.
Id suggest checking that the two external DMA signaling lines aren't
attached to any circuitry you may be using.
Does anyone fancy co-operating on reverse engineering and open sourcing
the SDcard driver?
Is doing that legal?
-Brett
------------------------------------
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/ts-7000/
<*> Your email settings:
Individual Email | Traditional
<*> To change settings online go to:
http://groups.yahoo.com/group/ts-7000/join
(Yahoo! ID required)
<*> To change settings via email:
<*> To unsubscribe from this group, send an email to:
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
|