Hi Johannes, On Wed, Aug 17, 2022 at 1:30 AM Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote: > > On Wed, 2022-08-17 at 01:28 -0700, Sean Wang wrote: > > Based on mt76 driver logic, alloc_hw would be needed before loading firmware > > because alloc_hw creates an instance of "struct mt76_dev*" the > > firmware loading relies on, > > and so the firmware capabilities cannot be decided before we alloc_hw > > in mt76 driver. > > > > I don't really see why you couldn't change that though? There's no > fundamental reason you need to load the firmware before registering with > mac80211? > It could be changed but it would break the consistency of the current mt76 driver. mt76 driver does the things in the following order - ieee80211_alloc_hw (where an instance of "struct mt76_dev *" would be created) - register bus operation into mt76 core (depending on struct mt76_dev to provide an abstraction layer for mt76 core to access bus) - read chip identifier (depending on bus operation) - load the firmware capabilities (depending on chip identifier) - initialize the hardware .... -ieee80211_register_hw If firmware capability is needed to load before ieee80211_alloc_hw, we need to create kind of similar functions to read chip identifiers and load firmware. I know It may not a strong reason not to change, but if we can support read firmware capabilities after alloc_hw, it provides flexibility to the vendor driver and helps mt7921 look more consistent and save a few changes across different mt7921 bus drivers (mt7921 now supports SDIO, USB, PCIe type driver). > And fundamentally, I'm not even sure how you are achieving a change of I kmemdup the const ops and ieee80211_alloc_hw with the duplicated ops the duplicated ops would be updated by the actual firmware capabilities before ieee80211_register_hw. > the ops - you're meant to point those to a *const* ops, so you need two > versions of the ops, one with and one without chanctx, and point to the > correct one at allocation ... > If you don't like the reason and the way I proposed in the patch, please let me know. I still can move on to the way you suggested here. > johannes
