On Fri, Jan 17, 2025 at 10:45:56AM -0600, Lucas De Marchi wrote: > [...] > > > > > > diff --git a/drivers/gpu/drm/xe/Kconfig b/drivers/gpu/drm/xe/Kconfig > > > > > > index b51a2bde73e29..50cf80df51900 100644 > > > > > > --- a/drivers/gpu/drm/xe/Kconfig > > > > > > +++ b/drivers/gpu/drm/xe/Kconfig > > > > > > @@ -59,6 +59,20 @@ config DRM_XE_DISPLAY > > > > > > help > > > > > > Disable this option only if you want to compile out display support. > > > > > > > > > > > > +config DRM_XE_DP_TUNNEL > > > > > > + bool "Enable DP tunnel support" > > > > > > + depends on DRM_XE > > > > > > + depends on USB4 > > > > > > + select DRM_DISPLAY_DP_TUNNEL > > > > > > + default y > > > > > > + help > > > > > > + Choose this option to detect DP tunnels and enable the Bandwidth > > > > > > + Allocation mode for such tunnels. This allows using the maximum > > > > > > + resolution allowed by the link BW on all displays sharing the > > > > > > + link BW, for instance on a Thunderbolt link. > > > > > > + > > > > > > + If in doubt say "Y". > > > > > > + > > > > > > > > > > I'm sort of wondering why we have this (and the i915 one) as > > > > > user-selectable config options at all. Is it ever reasonable for the > > > > > user to disable this if USB4 is enabled? > > > > > > > > On platforms that don't support DP tunneling, while supporting other > > > > USB4 functionality (or for systems w/o any TypeC/DP connectors) it would > > > > make sense to disable this option. > > > > > > isn't this too fine grained? if we expose every single functionality of > > > the driver like this we will bury distros on configs and exponentially > > > explode the testing combination. And yes, this broke the build for me. > > > > The tunneling functionality depends on USB4, BW allocation could fail > > without that. The option being user selectable also makes sense to me, > > as it has a size (~30kB) and runtime overhead (detecting tunnels and > > allocating/freeing BW), only required if the user has a dock/multiple > > displays. > > I will leave this up to the display maintainers - I still think it's too > fine grained to have this option as user selectable and worse, in 2 > drivers.... does the user have to know which driver officially support > that hardware to enable one and disable the other? All the display options should be configured at one place, but that's only feasible with a separate display module (which is the goal afaik). > Lucas De Marchi
