why the usb camera pop-up a dialog ask me to install driver,but i have already install the usb driver,and i find in my regedit have several link in the same GUID ,I don’t know why the usb ask me install driver? is this the problem of the hardware usb chips driver or my camera usb driver have some bug?
zhonghong200@163.com wrote:
why the usb camera pop-up a dialog ask me to install driver,but i have already install the usb driver,and i find in my regedit have several link in the same GUID ,I don’t know why the usb ask me install driver? is this the problem of the hardware usb chips driver or my camera usb driver have some bug?
If you do not have a serial number in your descriptors, then every time
you plug the camera into a different USB port for the first time, it
will be seen as a brand new device, and you will get a driver popup.
That’s the way Windows works.
The solution, if that annoys you, is to put a serial number in your
descriptors, something you should be doing anyway.
–
Tim Roberts, xxxxx@probo.com
Providenza & Boekelheide, Inc.
thank you Tim Roberts,you are Enthusiasm and helpful.
every time i plug the camera into a different usb port for the first time, it get a driver popup.
may i ask you another question, you say must have a serial number in my descriptors.This operation is in the hardware usb chip driver or in my PC Camera driver,thank you very much indeed.
how to add a serial number in my descriptors?
Descriptors were written in your device . it can be queried in your camera driver .
*serial number* indicating a unique device instance .Google on it .
you must make sure that you really want this descriptor and ask the hardware engineer to add that.
Consider passing the WHQL or verifying the driver as well.
And just so you are aware, every device you produce and sell must have its own unique serial number which may add to your manufacturing costs.
d
dent from a phpne with no keynoard
-----Original Message-----
From: xxxxx@hotmail.com
Sent: November 04, 2010 7:47 PM
To: Windows System Software Devs Interest List
Subject: RE:[ntdev] why the usb camera pop-up a dialog ask me to install driver,but i already install
Descriptors were written in your device . it can be queried in your camera driver .
serial number indicating a unique device instance .Google on it .
you must make sure that you really want this descriptor and ask the hardware engineer to add that.
Consider passing the WHQL or verifying the driver as well.
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zhonghong200@163.com wrote:
every time i plug the camera into a different usb port for the first time, it get a driver popup.
Yes. Assuming you don’t have a serial number, that is exactly how
Windows works.
may i ask you another question, you say must have a serial number in my descriptors.This operation is in the hardware usb chip driver or in my PC Camera driver,thank you very much indeed.
It is one of the USB descriptors in the device, usually stored in
firmware. You should have been able to figure that out. If it was part
of the driver, how could it affect the driver installation process?
–
Tim Roberts, xxxxx@probo.com
Providenza & Boekelheide, Inc.
Doron Holan wrote:
And just so you are aware, every device you produce and sell must have its own unique serial number which may add to your manufacturing costs.
Well, although the recommendation is a very strong one, all you can
really say is that it SHOULD have its own unique serial number.
Although some device classes mandate a serial number (like mass
storage), the general USB spec does not.
–
Tim Roberts, xxxxx@probo.com
Providenza & Boekelheide, Inc.
On 11/05/2010 06:01 PM, Tim Roberts wrote:
Although some device classes mandate a serial number (like mass
storage), the general USB spec does not.
As I read it, Doron’s statement is conditional:
-
a USB device does not need to define a USB “Serial Number”
(iSerial string descriptor index == zero) -
but IF a USB device DOES define such a “Serial Number”
AND IF it is used on Windows, THEN the “Serial Number”
needs to be unique (=different for each device).
Otherwise Windows gets severe hiccups and BSODs.
Actually I have seen at least one device where the “USB serial number”
was not unique (a PMP bought in China).
As long as you never ever connect two of these at the same time to a
Windows PC, you are fine. Otherwise strange things can happen.
> Although some device classes mandate a serial number (like mass
storage), the general USB spec does not.
The most funny thing is Wi-Fi adapter without the USB serial (but with unique MAC for sure).
–
Maxim S. Shatskih
Windows DDK MVP
xxxxx@storagecraft.com
http://www.storagecraft.com
thank you ,my friends.