RE: How to stop reloading the driver when the USB dev ice is plugged i n same slot ?

NTDEV
1

Sri,
That is quite strange. I wonder if something is not getting installed
correctly, or is your hardware not returning consistent results? You might
check your devices behavior with a bus analyzer.

-J

At 01:58 PM 1/15/2003, you wrote:

Hi Doron

Thanks for the reply.

Presently I am trying with same port . Normally I don’t see reload everytime
. But some times I see this problem . And also this problem is more on some
machines . Don’t know why ?

And another thing , After I unplug my device and plug it back immediately,
some times I see OS reloading driver again as if it is a new device . I am
not able to understand this behaviour . Is this also by design ?

thanks in advance
sri.

-----Original Message-----
From: Doron Holan [mailto:xxxxx@windows.microsoft.com]
Sent: Wednesday, January 15, 2003 3:46 PM
To: NT Developers Interest List
Subject: [ntdev] RE: How to stop reloading the driver when the USB
device is plugged i n same slot ?

If the usb device has no serial number, the OS cannot uniquely identify
the device. This means that each time it is plugged into a new port, a
new device node is created and installed. For there to be no reinstall
when the device moves around on the machine, the device must be uniquely
identifiable within the system. What you are seeing is by design.

In short, there is no way to solve this problem other then to give your
device a unique serial number.

d

-----Original Message-----
From: Deevi, Srinivasa [mailto:xxxxx@microtune.com]
Sent: Wednesday, January 15, 2003 3:42 PM
To: NT Developers Interest List
Subject: [ntdev] How to stop reloading the driver when the USB device is
plugged i n same slot ?

Hi all,

I have a question about how to stop reloading the same driver in windows
2k/xp environment . The firmware does not send any serial number in its
descriptors . I believe that when the device is not sending any serial
number , the OS should not ask for driver again as if it is a new device
.
what makes OS to think that this is a new device ? Anybody has any idea
how
to solve this problem ?

thanks in advance
sri.

You are currently subscribed to ntdev as: xxxxx@windows.microsoft.com
To unsubscribe send a blank email to xxxxx@lists.osr.com

You are currently subscribed to ntdev as: xxxxx@microtune.com
To unsubscribe send a blank email to xxxxx@lists.osr.com

You are currently subscribed to ntdev as: zeppelin@io.com
To unsubscribe send a blank email to xxxxx@lists.osr.com

2

I believe I am doing something similar in my driver, and I have not had any
trouble with it trying to reload drivers for the child devices. Again, I
think that the re-enumeration is not seeing consistent results.

-J

At 03:50 PM 1/15/2003, you wrote:

Hi Doron

Thanks for the reply.

Our driver is kind of bus driver which has multiple child devices ( like USB
Audio , HID keypad devices ) .The child devices are treated as class devices
, the bus driver handles all enquiry about descriptors for the child devices
. After checking the setupapi.log files , I found that the child devices are
getting reenumerated again as if it is a new device . It happens when two
devices connected , and one device is plugged out and plugged in fast . I
could not find any special reason of reloading devices in setupapi.log file.
Should I send a serial number for the child device also during enumeration
in our bus driver ? If it is required, how should I handle this when
multiple usb devices are plugged in the driver ?

Thanks in advance
sri.

-----Original Message-----
From: Doron Holan [mailto:xxxxx@windows.microsoft.com]
Sent: Wednesday, January 15, 2003 4:06 PM
To: NT Developers Interest List
Subject: [ntdev] RE: How to stop reloading the driver when the USB dev
ice is plugged i n same slot ?

Perhaps your device is having enumeration errors. See if the VID and
PID are what you expect them to be, %windir%\setupapi.log will have the
generated hwid’s. it should also contain enough info to find out why
this is a new device; if not you could turn up setupapi debugging (see
the ddk) and try to repro.

d

-----Original Message-----
From: Deevi, Srinivasa [mailto:xxxxx@microtune.com]
Sent: Wednesday, January 15, 2003 3:59 PM
To: NT Developers Interest List
Subject: [ntdev] RE: How to stop reloading the driver when the USB dev
ice is plugged i n same slot ?

Hi Doron

Thanks for the reply.

Presently I am trying with same port . Normally I don’t see reload
everytime
. But some times I see this problem . And also this problem is more on
some
machines . Don’t know why ?

And another thing , After I unplug my device and plug it back
immediately,
some times I see OS reloading driver again as if it is a new device . I
am
not able to understand this behaviour . Is this also by design ?

thanks in advance
sri.

-----Original Message-----
From: Doron Holan [mailto:xxxxx@windows.microsoft.com]
Sent: Wednesday, January 15, 2003 3:46 PM
To: NT Developers Interest List
Subject: [ntdev] RE: How to stop reloading the driver when the USB
device is plugged i n same slot ?

If the usb device has no serial number, the OS cannot uniquely identify
the device. This means that each time it is plugged into a new port, a
new device node is created and installed. For there to be no reinstall
when the device moves around on the machine, the device must be uniquely
identifiable within the system. What you are seeing is by design.

In short, there is no way to solve this problem other then to give your
device a unique serial number.

d

-----Original Message-----
From: Deevi, Srinivasa [mailto:xxxxx@microtune.com]
Sent: Wednesday, January 15, 2003 3:42 PM
To: NT Developers Interest List
Subject: [ntdev] How to stop reloading the driver when the USB device is
plugged i n same slot ?

Hi all,

I have a question about how to stop reloading the same driver in windows
2k/xp environment . The firmware does not send any serial number in its
descriptors . I believe that when the device is not sending any serial
number , the OS should not ask for driver again as if it is a new device
.
what makes OS to think that this is a new device ? Anybody has any idea
how
to solve this problem ?

thanks in advance
sri.

You are currently subscribed to ntdev as: xxxxx@windows.microsoft.com
To unsubscribe send a blank email to xxxxx@lists.osr.com

You are currently subscribed to ntdev as: xxxxx@microtune.com
To unsubscribe send a blank email to xxxxx@lists.osr.com

You are currently subscribed to ntdev as: xxxxx@windows.microsoft.com
To unsubscribe send a blank email to xxxxx@lists.osr.com

You are currently subscribed to ntdev as: xxxxx@microtune.com
To unsubscribe send a blank email to xxxxx@lists.osr.com

You are currently subscribed to ntdev as: zeppelin@io.com
To unsubscribe send a blank email to xxxxx@lists.osr.com