6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx> commit 51c1b42a232f17743cd825be6790cb64735ff98f upstream. We missed setting the CCS mode during resume and engine resets. Create a workaround to be added in the engine's workaround list. This workaround sets the XEHP_CCS_MODE value at every reset. The issue can be reproduced by running: $ clpeak --kernel-latency Without resetting the CCS mode, we encounter a fence timeout: Fence expiration time out i915-0000:03:00.0:clpeak[2387]:2! Fixes: 6db31251bb26 ("drm/i915/gt: Enable only one CCS for compute workload") Reported-by: Gnattu OC <gnattuoc@xxxxxx> Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/10895 Signed-off-by: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx> Cc: Chris Wilson <chris.p.wilson@xxxxxxxxxxxxxxx> Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx> Cc: Matt Roper <matthew.d.roper@xxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> # v6.2+ Tested-by: Gnattu OC <gnattuoc@xxxxxx> Reviewed-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> Tested-by: Krzysztof Gibala <krzysztof.gibala@xxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20240426000723.229296-1-andi.shyti@xxxxxxxxxxxxxxx (cherry picked from commit 4cfca03f76413db115c3cc18f4370debb1b81b2b) Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/i915/gt/intel_gt_ccs_mode.c | 6 +++--- drivers/gpu/drm/i915/gt/intel_gt_ccs_mode.h | 2 +- drivers/gpu/drm/i915/gt/intel_workarounds.c | 4 +++- 3 files changed, 7 insertions(+), 5 deletions(-) --- a/drivers/gpu/drm/i915/gt/intel_gt_ccs_mode.c +++ b/drivers/gpu/drm/i915/gt/intel_gt_ccs_mode.c @@ -8,14 +8,14 @@ #include "intel_gt_ccs_mode.h" #include "intel_gt_regs.h" -void intel_gt_apply_ccs_mode(struct intel_gt *gt) +unsigned int intel_gt_apply_ccs_mode(struct intel_gt *gt) { int cslice; u32 mode = 0; int first_ccs = __ffs(CCS_MASK(gt)); if (!IS_DG2(gt->i915)) - return; + return 0; /* Build the value for the fixed CCS load balancing */ for (cslice = 0; cslice < I915_MAX_CCS; cslice++) { @@ -35,5 +35,5 @@ void intel_gt_apply_ccs_mode(struct inte XEHP_CCS_MODE_CSLICE_MASK); } - intel_uncore_write(gt->uncore, XEHP_CCS_MODE, mode); + return mode; } --- a/drivers/gpu/drm/i915/gt/intel_gt_ccs_mode.h +++ b/drivers/gpu/drm/i915/gt/intel_gt_ccs_mode.h @@ -8,6 +8,6 @@ struct intel_gt; -void intel_gt_apply_ccs_mode(struct intel_gt *gt); +unsigned int intel_gt_apply_ccs_mode(struct intel_gt *gt); #endif /* __INTEL_GT_CCS_MODE_H__ */ --- a/drivers/gpu/drm/i915/gt/intel_workarounds.c +++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c @@ -2828,6 +2828,7 @@ add_render_compute_tuning_settings(struc static void ccs_engine_wa_mode(struct intel_engine_cs *engine, struct i915_wa_list *wal) { struct intel_gt *gt = engine->gt; + u32 mode; if (!IS_DG2(gt->i915)) return; @@ -2844,7 +2845,8 @@ static void ccs_engine_wa_mode(struct in * After having disabled automatic load balancing we need to * assign all slices to a single CCS. We will call it CCS mode 1 */ - intel_gt_apply_ccs_mode(gt); + mode = intel_gt_apply_ccs_mode(gt); + wa_masked_en(wal, XEHP_CCS_MODE, mode); } /*