The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 103309977589fe6be0f4314de4925737cdfc146f Mon Sep 17 00:00:00 2001

From: Chris Wilson chris@chris-wilson.co.uk Date: Sun, 29 Dec 2019 18:31:50 +0000 Subject: [PATCH] drm/i915/gt: Do not restore invalid RS state

Only restore valid resource streamer state from the context image, i.e. avoid restoring if we know the image is invalid.

Closes: https://gitlab.freedesktop.org/drm/intel/issues/446 Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Reviewed-by: Matthew Auld matthew.auld@intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20191229183153.3719869-4-chris... Cc: stable@vger.kernel.org (cherry picked from commit ecfcd2da335816516dc27434a65899a77886d80a) Signed-off-by: Joonas Lahtinen joonas.lahtinen@linux.intel.com

diff --git a/drivers/gpu/drm/i915/gt/intel_ring_submission.c b/drivers/gpu/drm/i915/gt/intel_ring_submission.c index a47d5a7c32c9..93026217c121 100644 --- a/drivers/gpu/drm/i915/gt/intel_ring_submission.c +++ b/drivers/gpu/drm/i915/gt/intel_ring_submission.c @@ -1413,14 +1413,6 @@ static inline int mi_set_context(struct i915_request *rq, u32 flags) int len; u32 *cs;

- flags |= MI_MM_SPACE_GTT; - if (IS_HASWELL(i915)) - /* These flags are for resource streamer on HSW+ */ - flags |= HSW_MI_RS_SAVE_STATE_EN | HSW_MI_RS_RESTORE_STATE_EN; - else - /* We need to save the extended state for powersaving modes */ - flags |= MI_SAVE_EXT_STATE_EN | MI_RESTORE_EXT_STATE_EN; - len = 4; if (IS_GEN(i915, 7)) len += 2 + (num_engines ? 4 * num_engines + 6 : 0); @@ -1589,22 +1581,21 @@ static int switch_context(struct i915_request *rq) }

if (ce->state) { - u32 hw_flags; + u32 flags;

GEM_BUG_ON(rq->engine->id != RCS0);

- /* - * The kernel context(s) is treated as pure scratch and is not - * expected to retain any state (as we sacrifice it during - * suspend and on resume it may be corrupted). This is ok, - * as nothing actually executes using the kernel context; it - * is purely used for flushing user contexts. - */ - hw_flags = 0; - if (i915_gem_context_is_kernel(rq->gem_context)) - hw_flags = MI_RESTORE_INHIBIT; + /* For resource streamer on HSW+ and power context elsewhere */ + BUILD_BUG_ON(HSW_MI_RS_SAVE_STATE_EN != MI_SAVE_EXT_STATE_EN); + BUILD_BUG_ON(HSW_MI_RS_RESTORE_STATE_EN != MI_RESTORE_EXT_STATE_EN); + + flags = MI_SAVE_EXT_STATE_EN | MI_MM_SPACE_GTT; + if (!i915_gem_context_is_kernel(rq->gem_context)) + flags |= MI_RESTORE_EXT_STATE_EN; + else + flags |= MI_RESTORE_INHIBIT;

- ret = mi_set_context(rq, hw_flags); + ret = mi_set_context(rq, flags); if (ret) return ret; }