在 2026-05-06三的 13:38 -0400，Dominique Belhachemi写道： > On Wed, May 6, 2026 at 1:14 PM Icenowy Zheng > <[email protected]> wrote: > > > > 在 2026-05-05二的 18:25 -0400，Dominique Belhachemi写道： > > > On Tue, May 5, 2026 at 5:03 AM Icenowy Zheng > > > <[email protected]> wrote: > > > > > > > > 在 2026-05-05二的 04:26 +0000，Dominique Belhachemi写道： > > > > > Wire up the standard non-coherent path matching the ingenic > > > > > DRM > > > > > driver. > > > > > > > > > > Tested on StarFive JH7110 (VisionFive 2 v1.3B). > > > > > > > > Interesting, I am curious about other patches added to test > > > > this. > > > > > > > Hi, > > > > > > I tested this on Debian unstable with a slightly patched 7.0.3 > > > kernel > > > [1]. > > > The test branch contains your verisilicon series, Michal's JH7110 > > > display series [2], > > > and a JH7110 ccache change [3], which was also required to > > > communicate > > > with the BXE-4-32 firmware [4]. > > > > BTW did you run any rendering? I think the way currently powervr > > open > > source driver works requires "coherent memory" (although it's > > usually > > implemented as uncached memory). > > Yes, GPU dispatches run with [4]. > Compute shaders run fine, but rendering crashes after a few frames. > > > > > > > This change here is only used to remove the ugly framebuffer > > > stripes > > > on the console and in the desktop environment. > > > > But I still think it'd be better to implement proper uncached > > memory > > support instead of flushing caches with dirty tracking. > > Maybe, this patch is just a working alternative.
I wonder whether it's possible to detect the availability of uncached memory. At least detecting using `of_dma_is_coherent()` isn't enough because it will only be true when the device is fully coherent with the CPU (snooping CPU cache). Thanks, Icenowy > > Dominique > > > > > > > [1] > > > https://github.com/domibel/linux/tree/jh7110_dc8200_hdmi_v7.0.3 > > > [2] > > > https://lore.kernel.org/lkml/[email protected]/ > > > [3] > > > https://lore.kernel.org/lkml/[email protected]/ > > > [4] > > > https://github.com/domibel/linux/tree/powervr_on_jh7110_visionfive2_v7.0.3 > > > > The POW_RASCALDUST thing looks quite interesting, maybe I should > > investigate it further. > > > > Thanks, > > Icenowy > > > > > > Dominique > > > >
