On Wed, Jan 19, 2022 at 12:30:04PM -0800, Lucas De Marchi wrote: > On Tue, Jan 18, 2022 at 02:01:45PM -0600, Bjorn Helgaas wrote: > > Haha :) I was hoping not to touch it myself because I think this > > whole stolen memory thing is kind of nasty. It's not clear to me why > > we need it at all, or why we have to keep all this device-specific > > logic in the kernel, or why it has to be an early quirk as opposed to > > a regular PCI quirk. We had a thread [1] about it a while ago but I > > don't think anything got resolved. > > I was reading that thread again and thinking what we could do to try to > resolve this. I will reply on that thread. Great! I hope there's some way around this. > > But to try to make forward progress, I applied patch 1/5 (actually, > > the updated one from [2]) to my pci/misc branch with the updated > > commit log and code comments below. > > thanks. I found the wording in the title odd as when I read "first" it > gives me the impression it's saying there could be more, which is not > possible. I said "first integrated GPU" because Linux doesn't control what devices are in the system; it just has to deal with whatever it finds. All one can tell from the code is that if we find one or more devices that appear in intel_early_ids[], we reserve stolen memory for the first such device. System-specific knowledge might tell you that there should only be one integrated GPU, but there's no constraint like that in Linux. Bjorn
