INTMS/INTMC not being used in NVME interrupt handling

From: Bharat Kumar Gogada
Date: Wed May 16 2018 - 08:02:41 EST


Hi,

As per NVME specification:
7.5.1.1 Host Software Interrupt Handling
It is recommended that host software utilize the Interrupt Mask Set and Interrupt Mask Clear (INTMS/INTMC)
registers to efficiently handle interrupts when configured to use pin based or MSI messages.

In kernel 4.14, drivers/nvme/host/pci.c function nvme_isr
doesn't use these registers.

Any reason why these registers are not used in nvme interrupt handler ?

Why NVMe driver is not using any bottom half and processing all completion queues
in interrupt handler ?

Regards,
Bharat