Messages in this thread | | | Subject | Re: [PATCH v5 4/5] Driver core: platform: Add devm_platform_get_irqs_affinity() | From | John Garry <> | Date | Wed, 9 Dec 2020 19:04:02 +0000 |
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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@huawei.com/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
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