usb multicard reader is not stopping ?

  • Thread starter Thread starter robm
  • Start date Start date
R

robm

when i click on stop device for a lexar usb 2.0 multicard reader ,the device
disappears from USB devices and the generic drives go awa then a window pops
up and says safe to remove the Card/Device

*BUT* within 2 seconds after the "safe to remove card " popup the USB
device, generic storage and the SD Card are all reloaded/re-initiallized
into the USB device tree,

should not re-load the devices until i dis/re-connect the Card Reader as i
understand ?

so the problem is i never get a chance to pull the SD/CF cards before they
are reloaded and re-connected after the stop operation which is supposedly a
un-safe state to pull SD card ?

I had this device connected to a PC (now dead) that worked as expected, the
Stop caused the USB card reader and the generic storage for SD/CF cards to
disappear from USB device tree and the device remained off dis-connected
until i pulled and re-connected the card-reader USB cable

any ideas or settings to try and fix this problem.

currently it seems the Win2K recognizes and installs "Generic Storage"
driver for the Card Reader i loaded the LEXAR driver but it does not seem to
become involved as removing LEXAR driver gives no different behavior.

maybe it's a device driver assignment / assocition problme ?

help greatly needed

robm
 
I see the same thing happen with several different USB memory devices. It
appears to be Explorer logging the device back in after it's been ejected.
This doesn't seem to cause any problems. Any changes have already been
written to the device. I think we just have to live with it.
 
thanks for reply

my biggest concern is the warning that one should not pull a card from USB
card reader while the card is mounted/loaded in the USB storage device tree
?

since i do not understand the inner workings of the USB device manager i
hope that the real issue is, as you suggest, that Stop/Ejection just forces
any cached writes to the mem card device and closes open files etc and that
the reload into device tree is just a benign or non-invasive operation

so you are convinced there is no worry with pulling a card that has been
mounted (so to speak) by USB storage driver as long as no writes or open
requests have occurred on the storage device ??

The peculiar thing is that this worked as expected on a previous PC but
after a bit of investigation my previous PC only supported USB v1.1 and the
new PC supports USB v2.0 so that may have been was and am using (W2k + SP4
+ rollup 1 + latest updates)

thanks again for advice
rob

Gary Chanson said:
I see the same thing happen with several different USB memory devices. It
appears to be Explorer logging the device back in after it's been ejected.
This doesn't seem to cause any problems. Any changes have already been
written to the device. I think we just have to live with it.

--
-GJC [MS Windows SDK MVP]
-Software Consultant (Embedded systems and Real Time Controls)
- http://www.mvps.org/ArcaneIncantations/consulting.htm
(e-mail address removed)


robm said:
when i click on stop device for a lexar usb 2.0 multicard reader ,the device
disappears from USB devices and the generic drives go awa then a window pops
up and says safe to remove the Card/Device

*BUT* within 2 seconds after the "safe to remove card " popup the USB
device, generic storage and the SD Card are all reloaded/re-initiallized
into the USB device tree,

should not re-load the devices until i dis/re-connect the Card Reader as i
understand ?

so the problem is i never get a chance to pull the SD/CF cards before they
are reloaded and re-connected after the stop operation which is supposedly a
un-safe state to pull SD card ?

I had this device connected to a PC (now dead) that worked as expected, the
Stop caused the USB card reader and the generic storage for SD/CF cards to
disappear from USB device tree and the device remained off dis-connected
until i pulled and re-connected the card-reader USB cable

any ideas or settings to try and fix this problem.

currently it seems the Win2K recognizes and installs "Generic Storage"
driver for the Card Reader i loaded the LEXAR driver but it does not seem to
become involved as removing LEXAR driver gives no different behavior.

maybe it's a device driver assignment / assocition problme ?

help greatly needed

robm
Click to expand...
Click to expand...
 
robm said:
thanks for reply

my biggest concern is the warning that one should not pull a card from USB
card reader while the card is mounted/loaded in the USB storage device tree
?

since i do not understand the inner workings of the USB device manager i
hope that the real issue is, as you suggest, that Stop/Ejection just forces
any cached writes to the mem card device and closes open files etc and that
the reload into device tree is just a benign or non-invasive operation

so you are convinced there is no worry with pulling a card that has been
mounted (so to speak) by USB storage driver as long as no writes or open
requests have occurred on the storage device ??

The peculiar thing is that this worked as expected on a previous PC but
after a bit of investigation my previous PC only supported USB v1.1 and the
new PC supports USB v2.0 so that may have been was and am using (W2k + SP4
+ rollup 1 + latest updates)
Click to expand...

That may be significant. Of three USB memory devices I have, I think I've
only seen this happen on the two which are USB 2.0 devices. I can't be sure
though because the third also uses a different driver because it's a memory
card reader.

I have never seen this scenario cause corruption and I don't think it ever
will because the only time there is a risk is when there is unsaved cached
data. As long as you don't write to the device after the eject operation, it
should be safe.
 
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