drm/i915/guc: kill doorbell code and selftests
Instead of relying on the workqueue, the upcoming reworked GuC submission flow will offer the host driver indipendent control over the execution status of each context submitted to GuC. As part of this, the doorbell usage model has been reworked, with each doorbell being paired to a single lrc and a doorbell ring representing new work available for that specific context. This mechanism, however, limits the number of contexts that can be registered with GuC to the number of doorbells, which is an undesired limitation. To avoid this limitation, we requested the GuC team to also provide a H2G that will allow the host to notify the GuC of work available for a specified lrc, so we can use that mechanism instead of relying on the doorbells. We can therefore drop the doorbell code we currently have, also given the fact that in the unlikely case we'd want to switch back to using doorbells we'd have to heavily rework it. The workqueue will still have a use in the new interface to pass special commands, so that code has been retained for now. With the doorbells gone and the GuC client becoming even simpler, the existing GuC selftests don't give us any meaningful coverage so we can remove them as well. Some selftests might come with the new code, but they will look different from what we have now so if doesn't seem worth it to keep the file around in the meantime. v2: fix comments and commit message (John) Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com> Cc: Michal Wajdeczko <michal.wajdeczko@intel.com> Cc: John Harrison <John.C.Harrison@Intel.com> Cc: Matthew Brost <matthew.brost@intel.com> Reviewed-by: John Harrison <John.C.Harrison@Intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191205220243.27403-3-daniele.ceraolospurio@intel.com
Please register or sign in to comment