As we now never read back our current head position from the CSB pointers register, and the HW itself doesn't use it to prevent overwriting unread CSB entries, we do not need to keep updating the register. As it turns out this register is not listed as being shadowed, and so requires forcewake -- but we haven't been taking forcewake around it so the writes has probably been regularly dropped. Fortuitously, we only read the value after a reset where it did not matter, and zero was the right answer (well, close enough).
Signed-off-by: Chris Wilson <[email protected]> Cc: Tvrtko Ursulin <[email protected]> Cc: Daniele Ceraolo Spurio <[email protected]> --- drivers/gpu/drm/i915/intel_lrc.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index 8b111a268697..a6268103663f 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -1100,8 +1100,6 @@ static void process_csb(struct intel_engine_cs *engine) } } while (head != tail); - writel(_MASKED_FIELD(GEN8_CSB_READ_PTR_MASK, head << 8), - execlists->csb_read); execlists->csb_head = head; } -- 2.18.0 _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
