> On Wed, Sep 14, 2022 at 04:51:03PM +0000, Winkler, Tomas wrote: > > > > > > On DG2, HuC loading is performed by the GSC, via a PXP command. The > > > load operation itself is relatively simple (just send a message to > > > the GSC with the physical address of the HuC in LMEM), but there are > > > timing changes that requires special attention. In particular, to > > > send a PXP command we need to first export the GSC as an aux device > > > and then wait for the mei-gsc and mei- pxp modules to start, which > > > means that HuC load will complete after i915 load is complete. This > > > means that there is a small window of time after i915 is registered > > > and before HuC is loaded during which userspace could submit and/or > > > check the HuC load status, although this is quite unlikely to happen (HuC > is usually loaded before kernel init/resume completes). > > > We've consulted with the media team in regards to how to handle this > > > and they've asked us to stall all userspace VCS submission until HuC is > loaded. > > > Stalls are expected to be very rare (if any), due to the fact that > > > HuC is usually loaded before kernel init/resume is completed. > > > > > > Timeouts are in place to ensure all submissions are unlocked in case > > > something goes wrong. Since we need to monitor the status of the mei > > > driver to know what's happening and when to time out, a notifier has > > > been added so we get a callback when the status of the mei driver > changes. > > > > > > Note that this series includes several mei patches that add support > > > for sending the HuC loading command via mei-gsc. We plan to merge > > > those patches through the drm tree because i915 is the sole user. > > > > > > v2: address review comments, Reporting HuC loading still in progress > > > while we wait for mei-gsc init to complete, rebase on latest mei-gsc > series. > > > > > > v3: fix cc list in mei patches. > > > > > > v4: update mei patches, fix includes, rebase on new FW fetch logic > > > and merged mei-gsc support. > > > > > > v5: update mei patches > > > > Greg, I hope I've addressed most of your comments. > > Can you please check if the mei patches are in acceptable state or anything > else can be improved with this series. Appreciated. > > These were sent 2 days ago, in the middle of a conference travel. > Please relax, there's no special rush needed here, you know better. Sure > In the mean time, if you are just waiting for my review, please take the time > to review other pending patches from other developers to help lighten the > load on me, and other maintainers. Fair enough, that's all I do every day anyway. Thanks Tomas
