Enabling atomic operations in L3 leads to unrecoverable GPU hangs, as the machine stops responding milliseconds after receipt of the reset request [GDRT]. By disabling the cached atomics, the hang do not occur and we presume the GPU would reset normally for similar hangs. Reported-by: Jason Ekstrand <jason@xxxxxxxxxxxxxx> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=110998 Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Cc: Jason Ekstrand <jason@xxxxxxxxxxxxxx> Cc: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx> Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx> --- Jason reports that Windows is not clearing L3SQCREG4:22 and does not suffer the same GPU hang so it is likely some other w/a that interacts badly. Fwiw, these 3 are the only registers I could find that mention atomic ops (and appear to be part of the same chain for memory access). --- drivers/gpu/drm/i915/gt/intel_workarounds.c | 8 ++++++++ drivers/gpu/drm/i915/i915_reg.h | 7 +++++++ 2 files changed, 15 insertions(+) diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c index 704ace01e7f5..ac94ed3ba7b6 100644 --- a/drivers/gpu/drm/i915/gt/intel_workarounds.c +++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c @@ -1349,6 +1349,14 @@ rcs_engine_wa_init(struct intel_engine_cs *engine, struct i915_wa_list *wal) wa_write_or(wal, GEN8_L3SQCREG4, GEN8_LQSC_FLUSH_COHERENT_LINES); + + /* Disable atomics in L3 to prevent unrecoverable hangs */ + wa_write_masked_or(wal, GEN9_SCRATCH_LNCF1, + GEN9_LNCF_NONIA_COHERENT_ATOMICS_ENABLE, 0); + wa_write_masked_or(wal, GEN8_L3SQCREG4, + GEN8_LQSQ_NONIA_COHERENT_ATOMICS_ENABLE, 0); + wa_write_masked_or(wal, GEN9_SCRATCH1, + EVICTION_PERF_FIX_ENABLE, 0); } } diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 24f2a52a2b42..e23b2200e7fc 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -7728,6 +7728,7 @@ enum { #define GEN11_LQSC_CLEAN_EVICT_DISABLE (1 << 6) #define GEN8_LQSC_RO_PERF_DIS (1 << 27) #define GEN8_LQSC_FLUSH_COHERENT_LINES (1 << 21) +#define GEN8_LQSQ_NONIA_COHERENT_ATOMICS_ENABLE REG_BIT(22) /* GEN8 chicken */ #define HDC_CHICKEN0 _MMIO(0x7300) @@ -11202,6 +11203,12 @@ enum skl_power_gate { /* Media decoder 2 MOCS registers */ #define GEN11_MFX2_MOCS(i) _MMIO(0x10000 + (i) * 4) +#define GEN9_SCRATCH_LNCF1 _MMIO(0xb008) +#define GEN9_LNCF_NONIA_COHERENT_ATOMICS_ENABLE REG_BIT(0) + +#define GEN9_SCRATCH1 _MMIO(0xb11c) +#define EVICTION_PERF_FIX_ENABLE REG_BIT(8) + #define GEN10_SCRATCH_LNCF2 _MMIO(0xb0a0) #define PMFLUSHDONE_LNICRSDROP (1 << 20) #define PMFLUSH_GAPL3UNBLOCK (1 << 21) -- 2.22.0 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
