Re: finding the parent of a device
From: Peter Wieland [MSFT] (peterwie_at_online.microsoft.com)
Date: 06/24/04
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Date: Thu, 24 Jun 2004 09:34:07 -0700
that will only work if the function driver sends unrecognized I/O controls
to the lower devices, which is not guaranteed.
-p
-- This posting is provided "AS IS" with no warranties, and confers no rights. "shahar" <shahar@discussions.microsoft.com> wrote in message news:1D539EDF-5B28-49C7-801A-27B169B97376@microsoft.com... > The only way I can think about detecting if a device is connected by USB > is to build a bus filter that attaches to every new PDO it sees when > IRP_MN_QUERY_DEVICE_RELATIONS returns. > This way it will be able to see all the IRP's for all the device tree > under the USB, > and by querying a device stack for a device interface that is implemented > by my driver I can detect if the device is connected to the USB. > this is realy realy ugly, can you think of a better way ? > > > "Doron Holan [MS]" wrote: > >> The more generic answer outside of storage, is that given a PDO, there is >> no >> way to find it's parent FDO in a standardized manner. >> >> d >> >> -- >> Please do not send e-mail directly to this alias. this alias is for >> newsgroup purposes only. >> This posting is provided "AS IS" with no warranties, and confers no >> rights. >> >> >> "Peter Wieland [MSFT]" <peterwie@online.microsoft.com> wrote in message >> news:%23pg0oNfWEHA.3972@TK2MSFTNGP12.phx.gbl... >> > Have you tried using IOCTL_STORAGE_QUERY_PROPERTY to get the device >> > descriptor for the disk you're talking to? It contains a field that >> > could >> > tell you the underlying bus type (assuming the drivers running the >> > device >> > set it) >> > >> > why only support USB? Why not smart-cards? Why not SD media? >> > >> > -p >> > >> > -- >> > This posting is provided "AS IS" with no warranties, and confers no >> rights. >> > "shahar" <shahar@discussions.microsoft.com> wrote in message >> > news:E2AA1E9D-3F74-4CD6-A0CF-183A299AB329@microsoft.com... >> > >I need to distinguish a USB disk from a IDE disk from a SCSI disk. >> > > >> > > "Peter Wieland [MSFT]" wrote: >> > > >> > >> why does it matter how it's connected? Either you've identified >> > >> your >> > >> disk-on-key device by its inquiry data, or you have no idea what the >> > >> device >> > >> is. Were you going to add code that distingushed a USB hard-disk >> > >> from >> a >> > >> smart-card from an SD card from a disk-on-key? >> > >> >> > >> If you're trying to just work with your device there are plenty of >> > >> ways >> > >> to >> > >> do it that will work better than trying to walk through the chain of >> > >> connected devices to see if one happens to be a USB hub. >> > >> >> > >> if you have a different goal you'll probably get better advice if >> > >> you >> > >> tell >> > >> us what the goal is, rather than asking how you implement a single >> > >> solution. >> > >> >> > >> -p >> > >> >> > >> -- >> > >> This posting is provided "AS IS" with no warranties, and confers no >> > >> rights. >> > >> "shahar" <shahar@discussions.microsoft.com> wrote in message >> > >> news:12DB0C3E-7994-4F4C-BE4A-E025C0625588@microsoft.com... >> > >> > But when for example I plug my disk-on-key to the USB hub, >> > >> > three devices are created: >> > >> > 1) A mass storage device with enumerator name USB >> > >> > 2) A disk drive device with enumerator name USBSTOR >> > >> > 3) A storage volume device with enumerator name STORAGE >> > >> > let's say my driver has a pointer to the storage volume's PDO, >> > >> > how can I know that this storage volume device is connected to a >> > >> > USB >> > >> > hub >> > >> > and not to the IDE for example ? >> > >> > the enumerator name can't help me in this case. >> > >> > knowing that the enumerator name is STORAGE says nothing about the >> > >> > parent >> > >> > of the device... >> > >> > Is there a way to get a pointer to PDO of the creator of some >> > >> > other >> PDO >> > >> > ? >> > >> > >> > >> > "Doron Holan [MS]" wrote: >> > >> > >> > >> >> you should never *ever* *ever* (did i say ever? i mean it!) send >> > >> >> a >> > >> >> query >> > >> >> device relations / BusRelations to the driver in question. this >> > >> >> irp >> > >> >> is >> > >> >> strictly for the pnp subsystem to send. >> > >> >> >> > >> >> why? >> > >> >> >> > >> >> because if there is a state change based on the relations >> > >> >> reported >> (a >> > >> >> new >> > >> >> PDO or the removal of one), you cannot enact that change. You >> > >> >> cannot >> > >> >> create >> > >> >> a new stack nor invoke a surprise removal on the removed PDO. >> > >> >> State >> > >> >> get's >> > >> >> lost, the driver who reported the change in its relations gets >> > >> >> put >> > >> >> into a >> > >> >> weird state and things go south really quickly. >> > >> >> >> > >> >> what you want is to ask the DO in question who its enumerator is, >> > >> >> IoGetDeviceProperty(..., DevicePropertyEnumeratorName, ..) will >> return >> > >> >> a >> > >> >> strig of the enumerator. So for a usb device it would be L"USB", >> for >> > >> >> a >> > >> >> parallel device probably L"LPT". >> > >> >> >> > >> >> d >> > >> >> >> > >> >> -- >> > >> >> Please do not send e-mail directly to this alias. this alias is >> > >> >> for >> > >> >> newsgroup purposes only. >> > >> >> This posting is provided "AS IS" with no warranties, and confers >> > >> >> no >> > >> >> rights. >> > >> >> >> > >> >> >> > >> >> "shahar" <shahar@discussions.microsoft.com> wrote in message >> > >> >> news:4B8B0986-1DA0-4CFB-9AFB-B9DF98046642@microsoft.com... >> > >> >> > When I want to know who are the children of a device I can send >> > >> >> > an >> > >> >> IRP_MN_QUERY_DEVICE_RELATIONS request to it with "type = >> > >> >> BusRelations", >> > >> >> but >> > >> >> how to I make the reversed operation ? >> > >> >> > Let's say I have a printer DO, how can I know if it is >> > >> >> > connected >> to >> > >> >> > a >> > >> >> parallel port or to a USB hub ? >> > >> >> >> > >> >> >> > >> >> >> > >> >> > >> >> > >> >> > >> > >> >> >>
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