[Mesa-dev] [PATCH 0/7] vulkan: Add VK_EXT_display_control and VK_EXT_display_surface_counter

[Keith Packard]

Here's a couple of reasonably straightforward extensions implemented
for both anv and radv drivers.

VK_EXT_display_surface_counter is a very simple extension which
adds an API, vkGetPhysicalSurfaceCapabilities2EXT, to extend the
existing vkGetPhysicalDeviceSurfaceCapabilitiesKHR and
vkGetPhysicalDeviceSurfaceCapablities2KHR interfaces.

The new interface uses a slightly different structure that includes a
new flags word, "supportedSurfaceCounters". This new field describes
the counters available from the underlying WSI layer. As this
extension doesn't provide any counters itself, each WSI layer
initializes this to zero for now.

VK_EXT_display_control is an extension specific to display surfaces
(those created via the KHR_display extension). This extension adds
DPMS support and fences which signal when vblank or monitor hotplug
events happen.

I've implemented the DPMS support and the vblank fence stuff; I
haven't bothered hooking up the monitor hotplug bits, although it
would be fairly simple.

To make the fences work on anv, I had to refactor the existing fence
waiting code to add the ability to spin waiting for any of a set of
heterogeneous fences (a mixture of syncobj and bo fences) to become
ready; this mirrors the same functionality in the radv driver,
although anv hadn't needed it before as it only supported homogenous
fence types (either all syncobj or all bo).

I've created a separate patch for this refactoring to try and reduce
the difficulty in reviewing that part.

-keith