[PATCH] TT S2-1600 allow more current for diseqc

[PATCH] TT S2-1600 allow more current for diseqc

[Guy Martin]

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Hi linux-media,

The following patch increases the current limit for the isl6423 chip
on the TT S2-1600 card. This allows DiSEqC to work with more complex
and current demanding configurations.

Signed-off-by: Guy Martin <gmsoft@tuxicoman.be>

Regards,
  Guy

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diff -r 7c0b887911cf linux/drivers/media/dvb/ttpci/budget.c
--- a/linux/drivers/media/dvb/ttpci/budget.c	Mon Apr 05 22:56:43 2010 -0400
+++ b/linux/drivers/media/dvb/ttpci/budget.c	Sun Apr 11 13:46:43 2010 +0200
@@ -461,7 +461,7 @@
 };
 
 static struct isl6423_config tt1600_isl6423_config = {
-	.current_max		= SEC_CURRENT_515m,
+	.current_max		= SEC_CURRENT_800m,
 	.curlim			= SEC_CURRENT_LIM_ON,
 	.mod_extern		= 1,
 	.addr			= 0x08,

Re: [PATCH] TT S2-1600 allow more current for diseqc

[André Weidemann]

Hello Guy,
On 11.04.2010 23:18, Guy Martin wrote:

>
> Hi linux-media,
>
> The following patch increases the current limit for the isl6423 chip
> on the TT S2-1600 card. This allows DiSEqC to work with more complex
> and current demanding configurations.
>
> Signed-off-by: Guy Martin<gmsoft@tuxicoman.be>




I am sorry for the late reply.
I advise not to pull this change into the kernel sources.
The card has only been testet with the a maximum current of 515mA.
Anything above is outside the specification for this card.

Kind Regards
  André

Re: [PATCH] TT S2-1600 allow more current for diseqc

[Guy Martin]

On Wed, 28 Apr 2010 09:45:39 +0200
André Weidemann <Andre.Weidemann@web.de> wrote:

> I advise not to pull this change into the kernel sources.
> The card has only been testet with the a maximum current of 515mA.
> Anything above is outside the specification for this card.


I'm currently running two of these cards in the same box with this
patch.
Actually, later on I've even set curlim = SEC_CURRENT_LIM_OFF because
sometimes diseqc wasn't working fine and that seemed to solve the
problem.

I used to have skystar2 cards before and I did not run into those
issues. Diseqc just worked fine.

For reference each tt s2 is plugged to a diseqc switch with 4 output,
each output connected to a quad lnb.

Is there another way to solve this ?
Maybe add a module parameter for people who want to override the
default ?

Regards,
  Guy

Re: [PATCH] TT S2-1600 allow more current for diseqc

[André Weidemann]

Hello Guy,

On 28.04.2010 10:33, Guy Martin wrote:

> On Wed, 28 Apr 2010 09:45:39 +0200
> André Weidemann<Andre.Weidemann@web.de>  wrote:
>
>> I advise not to pull this change into the kernel sources.
>> The card has only been testet with the a maximum current of 515mA.
>> Anything above is outside the specification for this card.
>
>
> I'm currently running two of these cards in the same box with this
> patch.
> Actually, later on I've even set curlim = SEC_CURRENT_LIM_OFF because
> sometimes diseqc wasn't working fine and that seemed to solve the
> problem.
>
> I used to have skystar2 cards before and I did not run into those
> issues. Diseqc just worked fine.
>
> For reference each tt s2 is plugged to a diseqc switch with 4 output,
> each output connected to a quad lnb.


How come there is such a high current drain to drive the switch plus the 
LNBs? From what I understand, the switch should only power one LNB at a 
time. Usually the switch plus the LNB should not drain more than 
300-400mA, or am I wrong here?

> Is there another way to solve this ?
> Maybe add a module parameter for people who want to override the
> default ?


I think this could be done. Nevertheless, the card would still operate 
outside its specification.

Regards
  André

Re: [PATCH] TT S2-1600 allow more current for diseqc

[Guy Martin]

Hi Andre,

On Wed, 28 Apr 2010 14:29:10 +0200
André Weidemann <Andre.Weidemann@web.de> wrote:

> 
> How come there is such a high current drain to drive the switch plus
> the LNBs? From what I understand, the switch should only power one
> LNB at a time. Usually the switch plus the LNB should not drain more
> than 300-400mA, or am I wrong here?

This is what I understood as well. It's cheap switch and LNBs so
that may explain it :)

I don't know how I can measure the current being drained tho. I only
found out that increasing the limit made my setup work.

It may be as well that the isl6423 driver doesnt' set the limit
correctly and configures a lower current limit than what is expected.


> 
> > Is there another way to solve this ?
> > Maybe add a module parameter for people who want to override the
> > default ?
> 
> 
> I think this could be done. Nevertheless, the card would still
> operate outside its specification.


Ok I'll work on a patch in that direction. Probably an integer parameter
with multiple possible values allowing to choose the limit or disable
it and add a big fat warning along the way.

Cheers,
  Guy

Re: [PATCH] TT S2-1600 allow more current for diseqc

[Manu Abraham]

On Wed, Apr 28, 2010 at 12:33 PM, Guy Martin <gmsoft@tuxicoman.be> wrote:
> On Wed, 28 Apr 2010 09:45:39 +0200
> André Weidemann <Andre.Weidemann@web.de> wrote:
>
>> I advise not to pull this change into the kernel sources.
>> The card has only been testet with the a maximum current of 515mA.
>> Anything above is outside the specification for this card.
>
>
> I'm currently running two of these cards in the same box with this
> patch.
> Actually, later on I've even set curlim = SEC_CURRENT_LIM_OFF because
> sometimes diseqc wasn't working fine and that seemed to solve the
> problem.

I would advise to not do this: since disabling current limiting etc
will cause a large problem in the case of a short circuit thereby no
protection to the hardware. In such an event, it could probably damage
the tracks carrying power on the card as well as the tracks on the
motherboard, and in some cases the gold finches themselves and or the
PCI connector.

Generally, there are only a few devices capable of sourcing > 0.5A, So
I wonder ....

Regards,
Manu

Re: [PATCH] TT S2-1600 allow more current for diseqc

[hermann pitton]

Hi,

Am Mittwoch, den 28.04.2010, 17:13 +0400 schrieb Manu Abraham:
> On Wed, Apr 28, 2010 at 12:33 PM, Guy Martin <gmsoft@tuxicoman.be> wrote:
> > On Wed, 28 Apr 2010 09:45:39 +0200
> > André Weidemann <Andre.Weidemann@web.de> wrote:
> >
> >> I advise not to pull this change into the kernel sources.
> >> The card has only been testet with the a maximum current of 515mA.
> >> Anything above is outside the specification for this card.
> >
> >
> > I'm currently running two of these cards in the same box with this
> > patch.
> > Actually, later on I've even set curlim = SEC_CURRENT_LIM_OFF because
> > sometimes diseqc wasn't working fine and that seemed to solve the
> > problem.
> 
> I would advise to not do this: since disabling current limiting etc
> will cause a large problem in the case of a short circuit thereby no
> protection to the hardware. In such an event, it could probably damage
> the tracks carrying power on the card as well as the tracks on the
> motherboard, and in some cases the gold finches themselves and or the
> PCI connector.
> 
> Generally, there are only a few devices capable of sourcing > 0.5A, So
> I wonder ....
> 
> Regards,
> Manu

for the few devices I do have, you seem to be for sure right.

All the Creatix stuff drawing up to 900mA on a potentially dual isl6405
has direct voltage from the PSU over an extra floppy connector.

Max. 500mA should be sufficient with a DiSEqC 1.2 compliant rotor.
Nothing else should come above that limit.

I wonder, if someone close in reading specs just now, can tell if 900mA
can be sufficient for two rotors ;)

Andre, BTW, assuming you still have a CTX944 (md8800 Quad), can you
measure if the 16be:0008 device really does switch between 13 and 18V.

Mine does not, but is also not in the original PC and the 0007 and 0008
devices are swapped on the PCI bus compared to that one.

Seen from my limited skills, it should not make any difference. So I
don't know why some did report all is fine on 0008 and I can only say it
hangs on 18V after init from the i2c capable 0007 device and on exit it
powers down properly, that's all, but _never_ is on 13V.

Be aware, that RF loopthrough between the two DVB-S tuners is
enabled ...

Thanks,
Hermann

Re: [PATCH] TT S2-1600 allow more current for diseqc

[André Weidemann]

Hi Hermann,
On 30.04.2010 02:31, hermann pitton wrote:

> Hi,
>
> Am Mittwoch, den 28.04.2010, 17:13 +0400 schrieb Manu Abraham:
>> On Wed, Apr 28, 2010 at 12:33 PM, Guy Martin<gmsoft@tuxicoman.be>  wrote:
>>> On Wed, 28 Apr 2010 09:45:39 +0200
>>> André Weidemann<Andre.Weidemann@web.de>  wrote:
>>>
>>>> I advise not to pull this change into the kernel sources.
>>>> The card has only been testet with the a maximum current of 515mA.
>>>> Anything above is outside the specification for this card.
>>>
>>>
>>> I'm currently running two of these cards in the same box with this
>>> patch.
>>> Actually, later on I've even set curlim = SEC_CURRENT_LIM_OFF because
>>> sometimes diseqc wasn't working fine and that seemed to solve the
>>> problem.
>>
>> I would advise to not do this: since disabling current limiting etc
>> will cause a large problem in the case of a short circuit thereby no
>> protection to the hardware. In such an event, it could probably damage
>> the tracks carrying power on the card as well as the tracks on the
>> motherboard, and in some cases the gold finches themselves and or the
>> PCI connector.
>>
>> Generally, there are only a few devices capable of sourcing>  0.5A, So
>> I wonder ....
>>
>> Regards,
>> Manu
>
> for the few devices I do have, you seem to be for sure right.
>
> All the Creatix stuff drawing up to 900mA on a potentially dual isl6405
> has direct voltage from the PSU over an extra floppy connector.
>
> Max. 500mA should be sufficient with a DiSEqC 1.2 compliant rotor.
> Nothing else should come above that limit.
>
> I wonder, if someone close in reading specs just now, can tell if 900mA
> can be sufficient for two rotors ;)
>
> Andre, BTW, assuming you still have a CTX944 (md8800 Quad), can you
> measure if the 16be:0008 device really does switch between 13 and 18V.

You seem to mistake me for someone else. I do not have a CTX944 and 
never had.

Regards
  André

Re: [PATCH] TT S2-1600 allow more current for diseqc

[hermann pitton]

Hi André,

Am Freitag, den 30.04.2010, 07:44 +0200 schrieb André Weidemann:
> Hi Hermann,
[snip]
> >
> > Andre, BTW, assuming you still have a CTX944 (md8800 Quad), can you
> > measure if the 16be:0008 device really does switch between 13 and 18V.
> 
> You seem to mistake me for someone else. I do not have a CTX944 and 
> never had.
> 
> Regards
>   André

yes, sorry, over the years with tda10086 questions and those about BBC
HD reception I confused Weidemann with Weymann (Helmut), who had such a
device in 2005.

Cheers,
Hermann