On Mon, Apr 23, 2018 at 10:40:20PM +0800, Alex Deucher wrote: > On Mon, Apr 23, 2018 at 8:13 AM, Huang Rui <ray.huang at amd.com> wrote: > > On Mon, Apr 23, 2018 at 05:57:06PM +0800, Koenig, Christian wrote: > >> Hi Ray, > >> > >> Am 23.04.2018 11:47 schrieb Huang Rui <ray.huang at amd.com>: > >> > >> On Fri, Apr 20, 2018 at 05:59:16PM +0800, Koenig, Christian wrote: > >> > Am 20.04.2018 um 11:40 schrieb Huang Rui: > >> > > "aaabaf4 drm/amdgpu: defer test IBs on the rings at boot (V3)" > >> > > Above patch defers the execution of gfx/compute ib tests. However, at > >> that time, > >> > > the gfx may already go into idle state. If "idle" gfx receives command > >> > > submission, it will get hang in the system. So we must add is_gfx_on > >> checking at > >> > > start of ib tests. > >> > > >> > Do I see that right that you just skip the IB test when the GFX block is > >> > already turned of? In this case that would be a clear NAK. > >> > > >> > BTW: How do you detect that we need to turn GFX on again? > >> > >> Christian, I know point. But there is a hang issue if we would like try to > >> disable/enable gfxoff with SMC message at runtime. Actually, I am trying to > >> find a good sequence to fix it. After that, I can even expose an debugfs > >> interface to configure that. So I have to skip the test for the moment when > >> gfx is in "idle". > >> > >> > >> Working around that issue for the moment is ok, but please note that explicitly > >> in both the commit message and a code comment. > > > > OK. Will add it at V2. > > > >> > >> But don't you run into the same problem when the UMD starts to submit commands? > > > > When UMD starts, RLC firmware will detect the "draw" command, then it will > > power up gfx. So it won't have problem at that time. The mainly state > > machine doesn't expose to driver side yet. > > > >> > >> I mean the idea of the IB test is that you "simulate" an userspace command > >> submission and see if it works. > >> > > > > Yes, agree. Any idea to "simulate" the "draw" command? Or please wait for > > my fix for enabling/disabling gfxoff at runtime. > > > Is there some special formatting in the IB required? I don't really > see how this will work. There is likely tons of state before the > actual draw command in the IB. > No, there isn't. The mainly behavior to turn on/off gfx is almost in RLC firmware. From driver's perspective, we only just use smc mesg to enable/disable the feature. Thanks, Ray
