question on USB,Is the Hub's fault?

NTDEV
1

Hi all:
I have a strange question on USB.
I modify the DDK sample driver VideoCap to work with my camera, but different thing happened:
1)device plug in the host directly : it works well, but when we pull it out, and then plug again, the host can’t recognize it as a usb device but a unknow one. And if we disable the device, and then re-enable, the icon is marked with a yellow “!”, and the host ask us to reboot the computer.
2)device plug in a HUB : everything is OK!!! Is the Hub’s fault?
How could this happened?
Thanks!
K.Y

b???.???????&?v?'?ׯj?.n?Qyȩf??]?:.?˛???m??֛???zf???%y?ޞ?^?˛??^r*Lzfެ?…???l??ܢ

2

May be you are running into this problem
http://support.microsoft.com/support/kb/articles/q264/9/46.asp
http:

-Eliyas

-----Original Message-----
From: Kamasamikon [mailto:xxxxx@bhnec.nec.co.jp]
Sent: Wednesday, April 25, 2001 10:55 PM
To: NT Developers Interest List
Subject: [ntdev] question on USB,Is the Hub’s fault?

Hi all:

I have a strange question on USB.

I modify the DDK sample driver VideoCap to work with my camera,
but different thing happened:

1)device plug in the host directly : it works well, but when we
pull it out, and then plug again, the host can’t recognize it as a usb
device but a unknow one. And if we disable the device, and then
re-enable, the icon is marked with a yellow “!”, and the host ask us to
reboot the computer.

2)device plug in a HUB : everything is OK!!! Is the Hub’s
fault?

How could this happened?

Thanks!

K.Y

b嫮绠范\够?v诘譲菋&蔴畫~讬:.炈洷殊m?澲洉╀zf?y炞^拷菛±矉+
(???r??z{e?˛???m?m?{]z???&j)@u?Ӣ?칻?&ޱ??i?Z?G?j)m?W???u?칻-E?"?Ǧm??(Z?X???,??&</http:>

3

Hi Eliyas:
Thank you so much! :slight_smile:
But i still don’t know why everything is OK when we use a HUB!
Regards!
K.Y

----- Original Message -----
From: “Eliyas Yakub”
To: “NT Developers Interest List”
Sent: Friday, April 27, 2001 1:11 AM
Subject: [ntdev] RE: question on USB,Is the Hub’s fault?

> May be you are running into this problem
> http://support.microsoft.com/support/kb/articles/q264/9/46.asp
> http:
>
>
>
> -Eliyas
>
>
>
>
>
> -----Original Message-----
> From: Kamasamikon [mailto:xxxxx@bhnec.nec.co.jp]
> Sent: Wednesday, April 25, 2001 10:55 PM
> To: NT Developers Interest List
> Subject: [ntdev] question on USB,Is the Hub’s fault?
>
>
>
> Hi all:
>
> I have a strange question on USB.
>
> I modify the DDK sample driver VideoCap to work with my camera,
> but different thing happened:
>
> 1)device plug in the host directly : it works well, but when we
> pull it out, and then plug again, the host can’t recognize it as a usb
> device but a unknow one. And if we disable the device, and then
> re-enable, the icon is marked with a yellow “!”, and the host ask us to
> reboot the computer.
>
> 2)device plug in a HUB : everything is OK!!! Is the Hub’s
> fault?
>
> How could this happened?
>
> Thanks!
>
> K.Y
>
>
>
>
>
> b嫮绠范\够?v诘譲菋&蔴畫~讬:.炈洷殊m?澲洉╀zf?y炞^拷菛±矉+
> bvj]y{.n +zwZnV隊[hz{]z 4 lˢ
(???r??z{e?˛???m?m?{]z???&j)@u?Ӣ?칻?&ޱ??i?Z?G?j)m?W???u?칻-E?"?Ǧm??(Z?X???,??&</http:>

4

Hi Eliyas:
Thank you so much! :slight_smile:
1)
In your http://support.microsoft.com/support/kb/articles/q264/9/46.asp, it said:
“To work around this problem, either exit the application that is using the device, or restart the system.” But in fact, we didn’t run
the application at all. Is there any other implied system application that uses the device handle?
2)
I still don’t know why everything is OK when we use a HUB!
And Can I make the system issue IRP_MN_REMOVE_DEVICE so that we can avoid this? if yes, how should we do ??

Regards!
K.Y

----- Original Message -----
From: “Eliyas Yakub”
To: “NT Developers Interest List”
Sent: Friday, April 27, 2001 1:11 AM
Subject: [ntdev] RE: question on USB,Is the Hub’s fault?

> May be you are running into this problem
> http://support.microsoft.com/support/kb/articles/q264/9/46.asp
> http:
>
>
>
> -Eliyas
>
>
>
>
>
> -----Original Message-----
> From: Kamasamikon [mailto:xxxxx@bhnec.nec.co.jp]
> Sent: Wednesday, April 25, 2001 10:55 PM
> To: NT Developers Interest List
> Subject: [ntdev] question on USB,Is the Hub’s fault?
>
>
>
> Hi all:
>
> I have a strange question on USB.
>
> I modify the DDK sample driver VideoCap to work with my camera,
> but different thing happened:
>
> 1)device plug in the host directly : it works well, but when we
> pull it out, and then plug again, the host can’t recognize it as a usb
> device but a unknow one. And if we disable the device, and then
> re-enable, the icon is marked with a yellow “!”, and the host ask us to
> reboot the computer.
>
> 2)device plug in a HUB : everything is OK!!! Is the Hub’s
> fault?
>
> How could this happened?
>
> Thanks!
>
> K.Y
>
>
>
>
>
> b嫮绠范\够?v诘譲菋&蔴畫~讬:.炈洷殊m?澲洉╀zf?y炞^拷菛±矉+
> bvj]y{.n +zwZnV隊[hz{]z 4 lˢ
(???r??z{e?˛???m?m?{]z???&j)@u?Ӣ?칻?&ޱ??i?Z?G?j)m?W???u?칻-E?"?Ǧm??(Z?X???,??&</http:>