On Mon, Sep 09, 2024 at 08:40:30AM +0200, Thomas Zimmermann wrote: > Hi > > Am 09.09.24 um 07:15 schrieb Yan Zhao: > > Use ioremap_wc() instead of ioremap() to map framebuffer during driver > > probing phase. > > > > Using ioremap() results in a VA being mapped with PAT=UC-. Additionally, > > on x86 architectures, ioremap() invokes memtype_reserve() to reserve the > > memory type as UC- for the physical range. This reservation can cause > > subsequent calls to ioremap_wc() to fail to map the VA with PAT=WC to the > > same physical range for framebuffre in ttm_kmap_iter_linear_io_init(). > > Consequently, the operation drm_gem_vram_bo_driver_move() -> > > ttm_bo_move_memcpy() -> ttm_move_memcpy() becomes significantly slow on > > platforms where UC memory access is slow. > > I've noticed this too and pushed a major update that replaces the entire > memory management. [1] > > The patch is still welcome, I think, but you may want to rebase onto the > latest drm-misc-next branch. [2] > > Best regards > Thomas > > [1] https://patchwork.freedesktop.org/series/138086/ > [2] https://gitlab.freedesktop.org/drm/misc/kernel/-/tree/drm-misc-next Thanks! The updated version is at https://lore.kernel.org/all/20240909131643.28915-1-yan.y.zhao@xxxxxxxxx
