Hello! MSDN documentation (http://msdn.microsoft.com/en-us/library/ff536730(VS.85).aspx) states that PortCls should revoke mappings at KSSTATE_STOP. But for my WavePci miniports, neither in XP SP3, Vista SP2 nor Win7, PortCls does not revoke mappings when stream state is changed to KSSTATE_STOP (RevokeMappings is not called at all when the system is being prepared to hibernation). Thus, a stream is placed to the STOP state but still has mappings acquired. AC'97 example (up to Win7 WDK) contains the following comment in KSSTATE_STOP processing: // Just pause DMA. If we have mappings left in our queue, // portcls will call RevokeMappings to destroy them. Is such behavior a bug of PortCls or is it another "hint" that MS have not mentioned in their documentation? Should a miniport driver release all acquired mappings itself on a transition to KSSTATE_STOP? I think a stream should keep no mappings in the stopped state. Regards, Eugene ****************** WDMAUDIODEV addresses: Post message: mailto:wdmaudiodev@xxxxxxxxxxxxx Subscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=subscribe Unsubscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=unsubscribe Moderator: mailto:wdmaudiodev-moderators@xxxxxxxxxxxxx URL to WDMAUDIODEV page: http://www.wdmaudiodev.com/