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SCSI Miniport Driver's HwScsiEnableInterruptsCallback Routine

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A HwScsiEnableInterruptsCallback routine finishes processing an interrupt-driven I/O operation without inhibiting I/O operations for other devices in the machine.

When the HwScsiEnableInterruptsCallback routine gets control, all system device interrupts are enabled except from the HBA because the HwScsiInterrupt routine disabled interrupts on the HBA before it called ScsiPortNotification. Thus, the miniport driver's HwScsiInterrupt routine cannot be called and cannot disturb the context data it set up about the current operation while the HwScsiEnableInterruptsCallback routine is running.

A HwScsiEnableInterruptsCallback routine should do the following:

  1. Use the context that was set up for the operation in the input device extension to complete processing of the request that caused the interrupt.

  2. Call ScsiPortNotification with the NotificationTypeRequestComplete and the just-satisfied SRB.

  3. Call ScsiPortNotification with the NotificationTypeNextRequest, or with NextLuRequest if the HBA supports tagged queuing or multiple requests per logical unit.

  4. Call ScsiPortNotification with a pointer to the device extension, the NotificationTypeCallDisableInterrupts, and the miniport driver's HwScsiDisableInterruptsCallback routine, described in SCSI Miniport Driver's HwScsiDisableInterruptsCallback Routine.

  5. Return control.

The NT-based operating system ScsiPortNotification routine calls the HwScsiDisableInterruptsCallback routine with a subset of the system device interrupts disabled. No device interrupt with a system-assigned hardware priority (IRQL) less than or equal to the HBA's can occur.

See Managing Hardware Priorities for more information.