[linux-dvb] DST/BT878 module customization (.. was: Critical points about ...)

Markus Rechberger mrechberger at gmail.com
Wed May 2 19:33:00 CEST 2007

On 5/2/07, Manu Abraham <abraham.manu at gmail.com> wrote:
> Uwe Bugla wrote:
> > -------- Original-Nachricht --------
> > Datum: Wed, 02 May 2007 17:30:32 +0400
> > Von: Manu Abraham <abraham.manu at gmail.com>
> > An: Trent Piepho <xyzzy at speakeasy.org>
> > CC: Simon Arlott <simon at fire.lp0.eu>, Linux Kernel Mailing list
> <linux-kernel at vger.kernel.org>, torvalds at linux-foundation.org, Jan
> Engelhardt <jengelh at linux01.gwdg.de>, helge.hafting at aitel.hist.no,
> akpm at linux-foundation.org, Linux DVB <linux-dvb at linuxtv.org>
> > Betreff: Re: [linux-dvb] DST/BT878 module customization (.. was:
> Critical	points	about ...)
> >
> >> Trent Piepho wrote:
> >>> On Tue, 1 May 2007, Simon Arlott wrote:
> >>>> On 30/04/07 22:17, Markus Rechberger wrote:
> >>>>> From my side I do not see any problem with that patch, if someone else
> >>>>> has a problem with it please state out the reason.
> >>>> I have no problem with the patch since it has nothing to do with my DVB
> >>>> card but you're only encouraging Uwe to be abusive since it seems to
> >>>> help get him what he wants:
> >>> I've been aware of the problem with dst not fully using the dvb
> >> customization
> >>> systems(*) for a long time.  It came up when dvb_attach() et al were
> >> first
> >>> being integrated, well before any rejected patches or strongly worded
> >> emails
> >>> or whatever from certain people that I'm aware of.
> >>>
> >> Well, your understanding of the device is quite limited and hence your
> >> comments and patches.
> >>
> >> The DST as it refers to is an embedded system a x86 Compatible RISC core
> >> [1] running at 20Mhz with 4MB Flash and 1MB RAM. The device has it's own
> >> IO and 2 DMA channels. What we have is a PQFP device
> >>
> >> This is the case in most cases. On some cheaper cards the embedded
> >> system is replaced by an 8 bit host microcontroller, to cut down costs
> >> where all the features are not required for a specific model
> >>
> >> Additionally this embedded system has a fast shovelling engine for the
> >> MPEG2 TS routing in between the
> >> This embedded system is connected to an actual
> >> (1) DVB frontend [2]
> >> (2) DVB CA interface [3]
> >> (3) Analog tuner
> >> (4) Audio interfaces
> >>
> >> These features are not the characteristics of a DVB Frontend. Here there
> >> is a DVB frontend like the normal ones which is hidden behind another
> >> pseudo bridge (So you don't have *any* access to the frontend at large)
> >>
> >> It is not necessary that *all* the dst cards (there are around ~15
> >> different variants of the same) do have the very same feature set.
> >>
> >> It does support DVB-S/DSS/DVB-C/DVB-T/ATSC depending on the cards. In
> >> fact it is a combo driver supporting the entire devices using a common
> >> command set
> >>
> >> In such a case it has more characteristics of the PCI bridge and in fact
> >> heavily tied to it and has it's own advantages.
> >>
> >>> I saw some discussion about dst by Markus, Mauro, and Andrew Morton, and
> >> since
> >>> I already know about the issues here, I felt I should post a patch for
> >> them
> >>> any other reasonable developers who might spend time on this.
> >>>
> >> I would think that it would be *extremely* rude for a person to send in
> >> patches for a device that which you don't understand at all, when it is
> >> for limiting the capability of the said device
> >
> > Hi Manu,
> > now if this is your evalution about it all, then let me tell you that I
> feel deeply sorry about it.
> >
> > Fact is:
> > Noone ever intended to send in patches limiting the capability of the said
> device (DST): I never did, Trent never did, Markus, Mauro, Andrew and others
> never did...
> >
> > Instead of this we all have very different knowledge and understanding
> levels, with you obviously being the one with the most elaborate and
> sophisticated level.
> >
> > So please why, instead of marking other people as "rude" whose solutions
> you do not appreciate at all, don't you just pick up the pratical proposals
> of other persons, even if you do not like them for some reasons, and at
> least try to raise them up to a far more better level?
> > Thus you definitely could avoid a lots of flaming, misunderstanding, and
> other counterproductive things to happen...
> > And this would conform to practising the synergetic principle, wouldn't
> it?
> >
> > Just one hint to help you: I remember a mail from Johannes in which he
> told me that you started up this whole development thing from a zero level
> some two or three years  ago. And Johannes not forgot to state that in the
> beginning you were nothing but nerving... (now add a smiley behind this,
> please, I'd deeply appreciate you to do).
> >
> > Above that:
> > 1. Taking part in testing the mm-tree and eliminating horrible bugs in it
> I never experienced but positive and warm compromise solutions in the end.
> Experiencing this is highly enlarging one's own personality.
> > 2. If you start up at zero (like you did once too - see above and ask
> Johannes if you do not remember at all) it is no good start at all if your
> humble effort is being thrown off after the first or second reject. That's
> highly discouraging, and if it happens very often the bad experience remains
> in one's own subjective perception filter.
> i did really start very small during those early stages. Johannes did
> help me a lot in many areas, he gave me a lot of valuable information,
> for which i am thankful to him. The same goes to Ralph Metzler and many
> others who gave me a big hand to bootup. Can't forget Andrew, Marcel et
> all in this regard (I did try to pass on such information to some
> people, they thought i was trying to sabotage their project etc.

Instead of describing what the matter was why don't you just try to
get forward now without playing the rebellian here, we sorted out a
way and accept it now.
Afterwards let's discuss what you want to change to get your changes in.

I really have the impression that you try to limit to give away useful
information, and afterwards you wonder why people don't understand
what you mean.
You should also describe the impact on other things (eg. your upcoming
work), don't expect that anyone on any mailinglist here knows what
code you host somewhere on your private servers at home.

> I stopped responding publicly as you might have seen. At one point i did
> throw away all DVB development, i did write the same on the #linuxtv IRC
> channel, did send a mail to Johannes too on that) It was just one user
> who got me back again on it, a North American DVB user
> In many cases it would be very nerving to work on hardware that is
> extremely undocumented. Sometimes you will have to wait for weeks for a
> certain person (persons who worked on the chips etc. On top of this
> people who worked on the devices will move away to newer organizations.
> Currently facing the same with another chip) to be free to provide an
> answer for the question. In short requires a lot of patience. On top of
> this when someone flames you in the little time one has.. well, many a
> times i lost my temper, yes.
> Sorry, if i was real bad.
> > 3. When I wrote patches since then I never gave up until there weren't any
> > a. fuzz factors
> > b. rejections
> > anymore. Instead I highly tried to put Andrew's "The perfect
> patch"-guidelines into practice. Although this kind of perfection reduces
> maintainers to gatekeepers in some cases - the borders of what is what and
> who is who are highly mutual...
> >
> > So the basic thing is just:
> > 1. To understand that everyone develops, independent from the knowledge
> and understanding level.
> > 2. To understand that everyone has good ideas at least sometimes,
> independent from knowledge and understanding level.
> >
> > And, even if you do not want to understand it out of whatever reason, it
> is no fun for any person to sound or act "abusive".
> > We're all just trying to search and find solutions, that's all.
> >
> > Above that I want to thank you for the theoretical introduction that you
> gave.
> > And I hope it helps after all.
> > But I am still very sad that the cx878 project died the way it died, so
> very close before its maturity to be implied into Mercurial tree. I did my
> best to help, but in the end I nothing but wasted time - and after all, I do
> not remember where the repository resides, after thaddatil.net has been down
> for months now... What a pity!
> No, the cx878 project never died. thadathil.net was hosted at my office.
> When the office moved a bit and some other complications, thadathil.net
> went offline. on top of that, at work i was given additional
> responsibilities for which i was struggling real hard. work with regards
> to DVB i just do it in my spare time, but i try to steal away some time
> from office work as well.
> Christoph usually used to review all my code as well as some others.
> With the upcoming KDE4, he was working more with kaffeine and had little
> time, himself.
> And as you might be aware i was working with a new delivery system
> DVB-S2. When one works with a new delivery system, the existing API
> proved too restrictive. Then working on which i trampled onto many
> issues (not even referring to the new delivery system, or the issues
> with the demodulator, mind you S2 is a bit complex and can really
> confuse people.) with DVB-CORE itself, which led to another API update
> other than multiproto, the Adapter API extensions. while on this again
> stumbled where advanced operations where performed at the in kernel
> demuxer, not forgetting an additional DSS demuxer is also needed in
> kernel for DSS support.

Is there any proposal available which describes these changes?

> With all these and struggling hard with 4 hours sleep, well i couldn't
> take all those flames (More than what you see on the ML's many people
> tend to send private mails for some reason or the other for help.
> Normally i don't reject anyone's request), you can say i was kind of
> worn out. Above all these some developers were very "unfriendly", some
> did mischief (politics) too, which led to a larger rift.

Try to get all parties satisfied here, if you don't want dvb_attach
for the DST/BT878 to be used here explain why so that everyone
understands it, I don't see that anything gets locked out because the
current code uses a very similar method at the moment (yes I know that
it's no frontend, but it's not even implemented as something really
If you have future plans about it write about them, and write why they
will hurt your work.


> So i chose to remain silent. That's all.
> During this period, Julian was kind enough to provide me hosting for my
> requirements. I will try to get thadathil.net up soon (many people used
> to have firmware downloads from there, also some people had access there
> for hosting test repo's and so on)
> Well, that was a long rant
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Markus Rechberger

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