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Archived from groups: microsoft.public.development.device.drivers,microsoft.public.win32.programmer.kernel,microsoft.public.windowsxp.device_driver.dev (More info?)
Hi
The first time I call IoGetDeviceObjectPointer on \Device\Serial0 the
function call do not fail.
Any attempts to open the COM port from user mode app. fails, which is fine.
But when I stop the driver i stil can't open the COM port from a user mode
app. ??
In my DriverUnload function I do call ObDereferenceObject() on the
fileobject returned by IoGetDeviceObjectPointer.
Any further attempts to call IoGetDeviceObjectPointer on \Device\Serial0
fails, (with error code 3221225506) which according to the DDK help files,
can't be returned ?
Isn't IoGetDeviceObjectPointer a combination of ZwCreateFile,
ObReferenceObjectByHandle, IoGetRelatedDeviceObject, ZwClose ??
So why can't I reopen the COM port ??
Thomas
Hi
The first time I call IoGetDeviceObjectPointer on \Device\Serial0 the
function call do not fail.
Any attempts to open the COM port from user mode app. fails, which is fine.
But when I stop the driver i stil can't open the COM port from a user mode
app. ??
In my DriverUnload function I do call ObDereferenceObject() on the
fileobject returned by IoGetDeviceObjectPointer.
Any further attempts to call IoGetDeviceObjectPointer on \Device\Serial0
fails, (with error code 3221225506) which according to the DDK help files,
can't be returned ?
Isn't IoGetDeviceObjectPointer a combination of ZwCreateFile,
ObReferenceObjectByHandle, IoGetRelatedDeviceObject, ZwClose ??
So why can't I reopen the COM port ??
Thomas