From ef87bba8280442bfbd07df5e409df85b023b39c2 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 28 Apr 2016 09:56:50 +0100 Subject: [PATCH] drm/i915: Update execlists context descriptor format commentary The comments describing the Context Descriptor Format are off by a bit for the size of the context ID. Signed-off-by: Chris Wilson Cc: Dave Gordon Cc: Tvrtko Ursulin Reviewed-by: Tvrtko Ursulin Link: http://patchwork.freedesktop.org/patch/msgid/1461833819-3991-16-git-send-email-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/intel_lrc.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index 4dedeaa3c788..217874198001 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -305,10 +305,11 @@ logical_ring_init_platform_invariants(struct intel_engine_cs *engine) * which remains valid until the context is unpinned. * * This is what a descriptor looks like, from LSB to MSB: - * bits 0-11: flags, GEN8_CTX_* (cached in ctx_desc_template) + * bits 0-11: flags, GEN8_CTX_* (cached in ctx_desc_template) * bits 12-31: LRCA, GTT address of (the HWSP of) this context - * bits 32-51: ctx ID, a globally unique tag (the LRCA again!) - * bits 52-63: reserved, may encode the engine ID (for GuC) + * bits 32-52: ctx ID, a globally unique tag (the LRCA again!) + * bits 53-54: mbz, reserved for use by hardware + * bits 55-63: group ID, currently unused and set to 0 */ static void intel_lr_context_descriptor_update(struct intel_context *ctx, @@ -319,9 +320,9 @@ intel_lr_context_descriptor_update(struct intel_context *ctx, lrca = ctx->engine[engine->id].lrc_vma->node.start + LRC_PPHWSP_PN * PAGE_SIZE; - desc = engine->ctx_desc_template; /* bits 0-11 */ + desc = engine->ctx_desc_template; /* bits 0-11 */ desc |= lrca; /* bits 12-31 */ - desc |= (lrca >> PAGE_SHIFT) << GEN8_CTX_ID_SHIFT; /* bits 32-51 */ + desc |= (lrca >> PAGE_SHIFT) << GEN8_CTX_ID_SHIFT; /* bits 32-52 */ ctx->engine[engine->id].lrc_desc = desc; } -- 2.20.1