Hello,
it seems that Microsoft not only removed the 1394b support but also the
irm support in xp sp2 (the contender bit is not set).
has anyone similar experince?
Uwe Kirst
[snip]
Hello,
it seems that Microsoft not only removed the 1394b support but also the
irm support in xp sp2 (the contender bit is not set).
has anyone similar experince?Uwe Kirst
Yes, I can confirm this as well. Since the IRM is responsible for
implementing the channels_available, bandwidth_available and
broadcast_channel registers, would this not break 1394 products that are not
IRM capable?
Philip Lukidis
Philip,
You are almost right, that will prevent products that are not IRM-capable
from functioning, but only if there are no other products on the bus that
are IRM-capable. But you knew that 
However, it is very easy for a device to implement IRM. The requirements are
to expose the registers for the remaining bandwidth and the allocated
channels and to supervise the lock operations on them. You also need to
reset them to the original values when a bus reset is detected. That’s
about all there is to it…
Glad to see you, btw
Mat
-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Philip Lukidis
Sent: Wednesday, August 18, 2004 4:59 PM
To: Windows System Software Devs Interest List
Subject: Re: [ntdev] 1394 +sp2
[snip]
Hello,
it seems that Microsoft not only removed the 1394b support but also the
irm support in xp sp2 (the contender bit is not set).
has anyone similar experince?Uwe Kirst
Yes, I can confirm this as well. Since the IRM is responsible for
implementing the channels_available, bandwidth_available and
broadcast_channel registers, would this not break 1394 products that are not
IRM capable?
Philip Lukidis
Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256
You are currently subscribed to ntdev as: xxxxx@encentrus.com
To unsubscribe send a blank email to xxxxx@lists.osr.com
> You are almost right, that will prevent products that are not IRM-capable
from functioning, but only if there are no other products on the bus that
are IRM-capable. But you knew that
The miniDV camcorders (like Canon ZR) were already IRM-capable as early as in
1999.
Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com
> Philip,
You are almost right, that will prevent products that are not IRM-capable
from functioning, but only if there are no other products on the bus that
are IRM-capable. But you knew thatHowever, it is very easy for a device to implement IRM. The requirements
are
to expose the registers for the remaining bandwidth and the allocated
channels and to supervise the lock operations on them. You also need to
reset them to the original values when a bus reset is detected. That’s
about all there is to it…Glad to see you, btw
Mat
Yes, you’re right, but I was thinking of the most basic topology possible,
(i.e. the device in question and the host controller node), given that
typically one must guarantee that one’s product must work a 1394 controller
card and one’s device.
Yes, you’re right, it would not be hard to implement. But of course if the
product in question was already released, well, costs would be incurred for
a device update. What’s funny is this IRM change is not present in SP2 RC2
(build 2149). That’s a pretty large change to occur between RC2 and RTM.
Likewise good to see you Matt.
Philip Lukidis
Hello,
I’m now thinking wether to implement or not a IRM in my firewire device.
If I would implement everything that is needed for an IRM (Bandwidth
available register, Channels available register, Topologiy map, Speed
map and so on)
would XP SP2 in that case use all the information it gets from my IRM?
I mean, would for example report XP the bus speed it gets from my IRM?
(GetMaxSpeedBetweenDevice; GetLocalHostInfo6) instead of looking at it’s
own Self ID packets?
I’m asking this explicit because that would be a workaround for the S100
limit of SP2 if the speed map of my IRM shows speed S400 instead of S800.
(A S400 speed limit is much more exceptable than a S100 limit)
Uwe Kirst
Maxim S. Shatskih wrote:
>You are almost right, that will prevent products that are not IRM-capable
>from functioning, but only if there are no other products on the bus that
>are IRM-capable. But you knew that
>
>The miniDV camcorders (like Canon ZR) were already IRM-capable as early as in
1999.Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com
Questions? First check the Kernel Driver FAQ at http://www.osronline.com/article.cfm?id=256
You are currently subscribed to ntdev as: xxxxx@gmx.de
To unsubscribe send a blank email to xxxxx@lists.osr.com