> -----Original Message----- > From: Intel-gfx [mailto:intel-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx] On Behalf > Of Wang, Zhi A > Sent: Tuesday, February 10, 2015 1:27 PM > To: Wang, Zhi A; Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > Subject: Re: About CTX_CONTEXT_CONTROL initialization in > populate_lr_context() intel_lrc.c > > Ping. If someone can confirm it. I can submit a patch, but I'm concerned > about introducing new register bit needs some internal process.... > > -----Original Message----- > From: Intel-gfx [mailto:intel-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx] On Behalf > Of Wang, Zhi A > Sent: Monday, February 09, 2015 11:05 PM > To: Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > Subject: About CTX_CONTEXT_CONTROL initialization in > populate_lr_context() intel_lrc.c > > Hi Gurus: > Forgive my junior HW knowledge, I just found that in execlist context > initialization function populate_lr_context(), this line: > > reg_state[CTX_CONTEXT_CONTROL+1] = > _MASKED_BIT_ENABLE((1<<3) | MI_RESTORE_INHIBIT); > > It seems the "Inhibit Synchronous Context Switch" bit is not set here, so > when HW is trying to wait some events, e.g. semaphore, according to Bspec, > per my basic understanding, it will switch out current context with some > reason bit set. Here comes my question, I think if this situation happen, > should i915 remember this context and try to re-schedule it in a proper time, > e.g. before submitting a new context until the context_completed bit in CSB > is set? I don't find a register that will remember the context switched out by > waiting event, so I think it should be i915 to handle this situation or just set > "Inhibit Synchronous Context Switch" bit here?... I don't think any of these events will be generated when execlists are enabled. I think there is a plan to use semaphores again, and a similar codepath will be needed to deal with context pre-emption when we support that, in order to re-submit pre-empted contexts. Thomas. _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
