On 09/12/2020 18:32, Greg KH wrote:
On Wed, Dec 02, 2020 at 06:36:56PM +0800, John Garry wrote:
Drivers for multi-queue platform devices may also want managed interrupts
for handling HW queue completion interrupts, so add support.
Hi Greg,
Why would a platform device want all of this? Shouldn't such a device
be on a "real" bus instead?
For this HW version, the device is on the system bus, directly
addressable by the CPU.
Motivation is that I wanted to switch the HW completion queues to use
managed interrupts.
What in-kernel driver needs this complexity? I can't take new apis
without a real user in the tree, sorry.
It's in the final patch in the series
https://lore.kernel.org/linux-scsi/1606905417-183214-1-git-send-email-john.garry@xxxxxxxxxx/T/#m0df7e7cd6f0819b99aaeb6b7f8939ef1e17b8a83.
I don't anticipate a huge number of users of this API in future, as most
multi-queue devices are PCI devices; so we could do the work of this API
in the driver itself, but the preference was not to export genirq
functions like irq_update_affinity_desc() or
irq_create_affinity_masks(), and rather have a common helper in the core
platform code.
Thanks,
John
