* Matthijs van Duin <matthijsvanduin@xxxxxxxxx> [200104 04:53]: > On Fri, Dec 20, 2019 at 04:57:11PM -0800, Tony Lindgren wrote: > > On my droid4 I noticed bad constant tearing on the LCD with stellarium in > > landscape mode with xorg-video-omap rotated with xrandr --rotate right. > > Every second or so update gets squeezed down in size to only the top half > > of the LCD panel. > > Odd, there's not really a good reason for rotation to have any effect on > whether tearing happens or not. > > BTW, with "top half", I assume you mean the top of the screen (i.e. > right side of the display), not the top of the display (i.e. left side > of the screen) ? Correct right side of the display that appears on top after rotate right. > > This issue does not happen with xrandr --rotate normal, or when HDMI > > display is also connected. > > Ehhhh, mirroring onto HDMI fixes the problem? Strange Yup just connecting an additional HDMI panel fixes the issue on the LCD :) > > Looking around what might affect BO_TILED, I noticed Matthijs had this > > change in his earlier pyra tiler patches. The earlier patch "XXX omapdrm: > > force tiled buffers to be pinned and page-aligned" has no commit log > > though, so I'm not sure what other issues this might fix. > > This is just part of a hacky patch series to improve performance for > userspace access to tiled buffers. Page alignment has no effect by > itself, but it's necessary to allow the tiled memory allocated by > tiled_reserve_2d() to be mapped directly into userspace instead of using > the really slow "usergart" mechanism. OK > You can find the full patch series in github.com/mvduin/linux branch > 4.15/patch/tiler-fast (based on mainline 4.15-rc6): > > ae664249050b ARM: introduce pgprot_device() > fc1e8ffd1334 drm: omapdrm: improve choice of memory type for tiled memory > these improve performance on omap5/dra7 by mapping tiled buffers as > "device" memory by default instead of the pointlessly slow "strongly > ordered" which is currently used as a workaround for the > incompatibility between TILER and the bizarre way the ARM Cortex-A15 > implements loads from normal non-cacheable memory. > > 3d4c98cc47dd XXX omapdrm: factor out _omap_gem_(un)pin > 70593563f531 XXX omapdrm: force tiled buffers to be pinned and page-aligned > e061e454afd5 XXX omapdrm: fast userspace mapping of tiled buffers > these greatly improve performance of userspace access to tiled > buffers (on all devices that use tiler) at the expense of using more > tiler virtual memory. note that tiler virtual memory is a less > scarce resource on omap5/dra7 where 2d and 1d mappings have separate > page tables than on omap4 where they share a page table. > > None of this should have any impact on tearing. OK so the alignment change just happens to fix the issue then. Regards, Tony _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
