Hi Thomas,
On Tue, Jul 27, 2021 at 08:27:07PM +0200, Thomas Zimmermann wrote:
DRM's IRQ helpers are only helpful for old, non-KMS drivers. Move the code behind CONFIG_DRM_LEGACY. Convert KMS drivers to Linux IRQ interfaces.
DRM provides IRQ helpers for setting up, receiving and removing IRQ handlers. It's an abstraction over plain Linux functions. The code is mid-layerish with several callbacks to hook into the rsp drivers. Old UMS driver have their interrupts enabled via ioctl, so these abstractions makes some sense. Modern KMS manage all their interrupts internally. Using the DRM helpers adds indirection without benefits.
Most KMs drivers already use Linux IRQ functions instead of DRM's abstraction layer. Patches 1 to 12 convert the remaining ones. The patches also resolve a bug for devices without assigned interrupt number. DRM helpers don't test for IRQ_NOTCONNECTED, so drivers do not detect if the device has no interrupt assigned.
Before diving into a review of these.. Any specific reason devm_request_irq is not used?
Sam