On Fri, Jan 25, 2019 at 02:46:55PM +0000, Emil Velikov wrote: > On Thu, 24 Jan 2019 at 16:58, Daniel Vetter <daniel.vetter@xxxxxxxx> wrote: > > > > This is only used by drm_irq_install(), which is an optional helper. > > And the right choice is to set it for all pci devices, and not for > > everything else. > > > Can you please add some information (or reference) why it's the right choice? pci devices can have a shared interrupt line. That's definitely the case for legacy pci, and I guess carries over to pcie. msi/msi-x interrupts will give you dedicated interrupts, but it doesn't really hurt to mark them as shared. I guess I could rephrase to state: "This is only used by drm_irq_install(), which is an optional helper. For legacy pci devices this is required (due to interrupt sharing without msi/msi-x), and just making this the default exactly matches the behaviour of all existing drivers using the drm_irq_install() helpers. In case that ever becomes wrong drivers can roll their own irq handling, as many drivers already do (for other reasons like needing a threaded interrupt handler, or having an entire pile of different interrupt sources)." That better? -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
