From 3936867dbc1eb8790aa5985a68d53e4303b3616f Mon Sep 17 00:00:00 2001 From: Mika Kuoppala Date: Thu, 11 Apr 2019 11:30:34 +0300 Subject: [PATCH] drm/i915: Disable read only ppgtt support for gen11 On gen11 writing to read only ppgtt page causes a gpu hang. This behaviour is different than with previous gen where read only ppgtt access is supported. On those, the write is just dropped without visible side effects. Disable ro ppgtt support on gen11 until a solution can be found to bring it into line with its predecessors. References: HSDES#1807136187 References: https://bugzilla.freedesktop.org/show_bug.cgi?id=108569 Cc: Chris Wilson Signed-off-by: Mika Kuoppala Acked-by: Chris Wilson Signed-off-by: Chris Wilson Link: https://patchwork.freedesktop.org/patch/msgid/20190411083034.28311-1-mika.kuoppala@linux.intel.com --- drivers/gpu/drm/i915/i915_gem_gtt.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index 736c845eb77f..8f460cc4cc1f 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -1228,7 +1228,7 @@ static int gen8_init_scratch(struct i915_address_space *vm) vm->scratch_pte = gen8_pte_encode(vm->scratch_page.daddr, I915_CACHE_LLC, - PTE_READ_ONLY); + vm->has_read_only); vm->scratch_pt = alloc_pt(vm); if (IS_ERR(vm->scratch_pt)) { @@ -1548,8 +1548,13 @@ static struct i915_hw_ppgtt *gen8_ppgtt_create(struct drm_i915_private *i915) ppgtt_init(i915, ppgtt); - /* From bdw, there is support for read-only pages in the PPGTT. */ - ppgtt->vm.has_read_only = true; + /* + * From bdw, there is hw support for read-only pages in the PPGTT. + * + * Gen11 has HSDES#:1807136187 unresolved. Disable ro support + * for now. + */ + ppgtt->vm.has_read_only = INTEL_GEN(i915) != 11; /* There are only few exceptions for gen >=6. chv and bxt. * And we are not sure about the latter so play safe for now. -- 2.30.2