Breton M. Saunders napsal(a):
>
>
> Daniel Smolik wrote:
> > Doug napsal(a):
> >
> >>
> >>
> >> --- In <ts-7000%40yahoogroups.com>
> <ts-7000%40yahoogroups.com>,
> >> "Breton M. Saunders" <> wrote:
> >>
> >> Hey Brett,
> >>
> >> > I am unconvinced by the stability of the sdcard driver.
> >>
> >> Me too. We first noticed this problem because it was causing corrupted
> >> versions of shared libraries to be loaded into RAM, causing a strange
> >> program crash. We also saw other odd behavior (playsound was cutting
> out
> >> on some sounds and making the sounds stutter, and saying invalid format
> >> on others). When we loaded our program from the NAND instead of the SD
> >> card all was fine. Hopefully it's an easy fix, we'll see...anyway,
> we've
> >> seen a lot of random weird behavior with the SD card and we're hoping
> >> this problem I reported is the root cause of it. We tried to reduce it
> >> down to a simple test case so it would be easy to reproduce.
> >>
> >> > 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.
> >>
> >> Thanks for the ideas...we'll definitely check on this on Monday to make
> >> sure. We've seen this problem on two TS-7390 boards, and on one of them
> >> I believe all we had hooked up externally was the two wires to the TS
> >> uart and an ethernet cable, so I dunno.
> >>
> >> > Does anyone fancy co-operating on reverse engineering and open
> sourcing
> >> > the SDcard driver?
> >> > Is doing that legal?
> >>
> >> Not sure on the legality of it. I think it would be easier to just take
> >> the binary blob as is and port the open source portion of the driver to
> >> newer kernel versions perhaps? It would be an interesting thing to try
> >> (either method).
> >>
> >>
> > But it is lot of work I spend lot of time to try port wrapper from
> 2.6.21 to 28 but it is not possible.
> > There are lot of internal changes in kernel BIO layer. I mean that
> wrapper driver must be rewritten from scratch.
> >
> Actually, I have repaired the wrapper for use with 2.6.27 - as I'm not
> convinced the memory management is correct in the later kernels yet -
> maybe someone can correct me on this.
>
> I also reverse engineered the blob part from object module for use on
> the ts7400 about 10 months ago. The reverse engineered blob works only
> on - rev 0 8 bit CPLD controllers (e.g. 7250 and 7400, not 73xx nor
> 78xx) - but one may infer from the blob dump that the 16 bit interfaces
> are fairly similar, and likely several oddities (e.g. hardware bugs) are
> fixed.
>
Great work. If you want tester I would like to help. I have
7400,7250,7800,7250-128,7200.
Regards
Dan
> Nothing is sacred in the controller blob - all of the SD commands are
> published; so TS's argument about not releasing the driver because they
> paid for access to secure documents doesn't apply anymore (it may have
> at one time). I suspect that TS's argument against publishing the
> driver source code is more of exposing bugs in the CPLD implementation,
> and/or showing their ugly code. If they would chill out and come clean
> with the code then we (the collective community) could get it working,
> burn in tested and supported on modern (e.g. usable) kernels.
>
> I have tested my implementation with Bonnie++, and it does seem to work
> on 10MiB test files - although I haven't done much more sophisticated
> burn-in testing. My driver also works with DMA reads, DMA writes are
> unsupported (similarly to the ts implementation).
>
> My main question - and primarily one for the GNU's lawyers is whether or
> not I can release the code under a GNU license.
>
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