From: Maíra Canal Date: Sat, 30 May 2026 18:37:42 +0000 (-0300) Subject: drm/v3d: Wait for pending L2T flush before cleaning caches X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=abf888b03a9805a3bc37948a0df443553b1c0910;p=thirdparty%2Fkernel%2Flinux.git drm/v3d: Wait for pending L2T flush before cleaning caches v3d_clean_caches() starts the cache-clean sequence by writing V3D_L2TCACTL_TMUWCF to V3D_CTL_L2TCACTL and then polling for that bit to clear. It does not, however, check for an L2T flush (L2TFLS) that may still be in flight from a previous operation. On pre-V3D 7.1 hardware, kicking off the TMU write-combiner flush while an L2T flush is still pending can clobber bits in L2TCACTL and cause cache inconsistencies. Poll for L2TFLS to clear before writing L2TCACTL on V3D < 7.1, ensuring any pending flush has completed before a new clean is issued. Cc: stable@vger.kernel.org Fixes: d223f98f0209 ("drm/v3d: Add support for compute shader dispatch.") Link: https://patch.msgid.link/20260530-v3d-fix-rpi4-freezes-v1-1-c2c8307da6ce@igalia.com Signed-off-by: Maíra Canal Reviewed-by: Iago Toral Quiroga --- diff --git a/drivers/gpu/drm/v3d/v3d_gem.c b/drivers/gpu/drm/v3d/v3d_gem.c index 75d9eccd7966..dd7da419702f 100644 --- a/drivers/gpu/drm/v3d/v3d_gem.c +++ b/drivers/gpu/drm/v3d/v3d_gem.c @@ -213,6 +213,14 @@ v3d_clean_caches(struct v3d_dev *v3d) trace_v3d_cache_clean_begin(dev); + /* GFXH-1897: Ensure pending flushes complete before writing L2TCACTL */ + if (v3d->ver < V3D_GEN_71) { + if (wait_for(!(V3D_CORE_READ(core, V3D_CTL_L2TCACTL) & + V3D_L2TCACTL_L2TFLS), 100)) { + drm_err(dev, "Timeout waiting for L2T clean\n"); + } + } + V3D_CORE_WRITE(core, V3D_CTL_L2TCACTL, V3D_L2TCACTL_TMUWCF); if (wait_for(!(V3D_CORE_READ(core, V3D_CTL_L2TCACTL) & V3D_L2TCACTL_TMUWCF), 100)) {