From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Thu, 25 Jan 2018 11:24:42 +0000
Subject: drm/i915/lrc: Clear context restore/save inhibit flags for new
contexts
Git-commit: 09b1a4e4b583b4c54c819563717949807fdbb640
Patch-mainline: v4.17-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166
CTX_CONTEXT_CONTROL (CTX_SR_CTL) operates as a masked register and so
will only apply the bits that are selected by the upper half. In the
case of selectively enabling sr inhibit, this may mean the context keeps
the current setting (so forgetting to save the context later, eventually
leading to a very upset GPU!).
Fixes: 517aaffe0c1b ("drm/i915/execlists: Inhibit context save/restore for the fake preempt context")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180125112443.12745-1-chris@chris-wilson.co.uk
Reviewed-by: Michel Thierry <michel.thierry@intel.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/gpu/drm/i915/intel_lrc.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -456,6 +456,12 @@ static void inject_preempt_context(struc
ce->ring->tail &= (ce->ring->size - 1);
ce->lrc_reg_state[CTX_RING_TAIL+1] = ce->ring->tail;
+ GEM_BUG_ON((ce->lrc_reg_state[CTX_CONTEXT_CONTROL + 1] &
+ _MASKED_BIT_ENABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT |
+ CTX_CTRL_ENGINE_CTX_SAVE_INHIBIT)) !=
+ _MASKED_BIT_ENABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT |
+ CTX_CTRL_ENGINE_CTX_SAVE_INHIBIT));
+
GEM_TRACE("%s\n", engine->name);
for (n = execlists_num_ports(&engine->execlists); --n; )
elsp_write(0, engine->execlists.elsp);
@@ -2123,6 +2129,8 @@ static void execlists_init_reg_state(u32
MI_LRI_FORCE_POSTED;
CTX_REG(regs, CTX_CONTEXT_CONTROL, RING_CONTEXT_CONTROL(engine),
+ _MASKED_BIT_DISABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT |
+ CTX_CTRL_ENGINE_CTX_SAVE_INHIBIT) |
_MASKED_BIT_ENABLE(CTX_CTRL_INHIBIT_SYN_CTX_SWITCH |
(HAS_RESOURCE_STREAMER(dev_priv) ?
CTX_CTRL_RS_CTX_ENABLE : 0)));