+Christian On Fri, Oct 04, 2019 at 02:05:46PM +0000, Mario.Limonciello@xxxxxxxx wrote: > > > > On Fri, Oct 4, 2019 at 11:19 AM Mika Westerberg > > <mika.westerberg@xxxxxxxxxxxxxxx> wrote: > > > > > > On Fri, Oct 04, 2019 at 11:07:34AM +0300, Yehezkel Bernat wrote: > > > > > Also if you can get the hw_vendor_id and hw_product_id from the kernel > > > > > does that mean you don't need to do the two reads or you still need > > > > > those? > > > > > > > > Are those the chip vendor or the OEM, in case they are different? > > > > > > Those are the actual USB4 hardware maker values, directly from > > > ROUTER_CS_0 (p. 287 in the USB4 spec). This almost certainly differ from > > > the OEM values from DROM we currently expose. > > > > Makes sense to me. Userspace can learn the relevant IDs that their NVM format > > is > > known. > > > > > > > > > Thinking about it again, I'd guess it shouldn't matter much, if the chip is from > > > > Intel, the FW supports NVM upgrade, isn't it? > > > > > > So the bottom line is that if the kernel thinks the router supports NVM > > > upgrade it exposes the nvm_active/nvm_non_active files etc. I think > > > fwupd uses this information to display user whether the device can be > > > upgraded or not (for example ICL cannot as the NVM is part of BIOS). > > > > Yes, fwupd already takes this into account, but the question here is how to > > handle cases that NVM is available but the format isn't known to > > userspace (yet). > > Exactly. > > > > > > > > > Exposing hw_vendor_id and hw_product_id may speed up fwupd because it > > > does not need to go over the active NVM to figure out whether the new > > > image is for the correct controller. > > > > It's not about finding the relevant image for upgrade (which must be searched > > for by looking in the DROM vendor/product values), but about the question if the > > NVM format is known to userspace and skip the parsing work if it's anyway going > > to fail. > > > > So yes, I think exposing vendor ID (and maybe also product ID) can improve the > > situation. > > > > Currently at probe time everything comes from udev except for the bit indicating > running in "native" mode or not. Just enough chunks of the NVM are read to determine > that (IE no reading up through DROM or jumping around). > > If Christian's patch to export generation is accepted I think that we could move that check > to only read -native if generation < 3. > > And if you export the hw_vendor_id and hw_product_id fields then that means USB4 devices > would require no reading from NVM at "probe" since we don't have to read a -native bit. Right. So I'm thinking instead of sw->generation what if we expose three new attributes: hw_vendor_id - Hardware Vendor ID read from ROUTER_CS_0. hw_product_id - Hardware Product ID read from ROUTER_CS_0. hw_version - Hardware USB4 version read from ROUTER_CS_4. This should allow userspace to determine what exactly the device is and which version it is. For example USB4 routers the hw_version is 0x20. @Christian, would this work for bolt as well?
