>> >> From memory, even on pat system we need mtrr for VRAM is PCI BAR. We >> cover it with a write combine MTRR. The whole ioctl is use by some ddx >> or maybe even directly the XServer to do this mtrr mess in userspace. > > Egads! So we have a _DRM_WRITE_COMBINING flag, which will continue to > work fine, but almost nothing uses it. > > I'm amazed this stuff works in the current code, though. Apparently > the memory type (WC or UC) of a drm mapping is determined by the mtrr > the driver set, but if one part of the BAR is textures or the > framebuffer and another part is an outgoing command ring, won't one of > them end up with the wrong memory type? Nobody sane puts the command ring in VRAM. Dave. -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
