PRB: Filtering of PCMCIA Device IRQ Request Mask
PSS ID Number: 195317
Article Last Modified on 10/15/2002
The information in this article applies to:
- Microsoft Win32 Device Driver Kit (DDK) Windows 95
This article was previously published under Q195317
SYMPTOMS
PCMCIA devices might appear to be unable to use all the possible IRQs
specified in the device's BASIC_LOG_CONF IRQ Request Mask. For example, the
BASIC_LOG_CONF IRQ Request Mask might specify FFFF, but the
FILTERED_LOG_CONF and ALLOC_LOG_CONF will likely show a value other than
FFFF, which limits the range of possible IRQs for the device.
CAUSE
The Windows socket driver walks through and tests all 16 IRQs and writes an
entry in the software section of the registry for the socket
(HKLM\System\CurrentControlSet\Services\Class\PCMCIA\XXXX) named IRQMask.
if the registry entry already exists, the socket driver does not go through
this process. This IRQMask is used to filter the BASIC_LOG_CONF IRQ Request
Mask. The filtering is dependent upon IRQ usage by other devices in the
system. The filtering is not affected by tuple data or INF overrides.
STATUS
This behavior is by design.
REFERENCES
Windows 95 DDK: PCMCIA; PnP
Keywords: kbBug kbDebug kbprb KB195317
Technology: kbAudDeveloper kbWin32DDK95 kbWin32DDKSearch kbWin32sSearch kbWin95search kbWinDDKSearch