Hi Marcin, Many thanks for your thoughtful, heartfelt response, and I don't disagree with your sentiments. The truth is that we have a messy situation. As a collective community of people who are passionate about the success of Arm in general purpose systems, I know many who would share my personal feeling that this is all beyond very unfortunate. That other architecture has working, robust, PCI IP that adheres to standards (more or less) correctly. There is no reason we can't either. But it takes a collective industry wide effort, alongside leadership from Arm (and others) to push things forward. I'm very impressed with where SystemReady is headed and there are great people behind making that happen. So I have faith that things will improve. Now is a good time to unite as an industry behind improving both the status quo (quirks) and future IP so that it is properly compliant. My opinion is that now is not a good moment to rework entirely how we do PCI enumeration to use an alternative scheme. Please see the below for more. On Thu, Mar 25, 2021 at 4:45 PM Marcin Wojtas <mw@xxxxxxxxxxxx> wrote: > So what we have after 4 years: > * Direct convincing of IP vendors still being a plan. Things need to improve here. I've *expressed* as much to certain folks around the industry. I'm not afraid to get more vocal. There is too much IP out there even now that is doing inexcusably non-compliant things. When I would talk to these vendors they didn't seem to take standards compliance seriously (to any standard) because they're used to making some BSP for some platform and nobody has stood thoroughly over them to the point of extreme discomfort so that they change their approach. It is now past time that we stand over these folks and get them to change. I am not afraid to get much more intense here in my approach and I would hope that others who feel similarly about standardization would also choose to engage with extreme vigor. Extreme vigor. It must become an extreme embarrassment for any of them to continue to have any IP that claims to be "PCI" which is....not PCI. > * Reverting the original approach towards MCFG quirks. > * Double-standards in action as displayed by 2 cases above. The truth is we've had an inconsistent approach. But an understandable one. It's painful to take quirks. I am grateful that the maintainers are willing to consider this approach now in order to get to where we want to be, but I completely understand the hesitance in the past. Along with the above, we all need to do all we can to ensure that quirks are an absolute last resort. It's one thing to have a corner case issue that couldn't be tested pre-silicon, but there is *no excuse* in 2021 to ever tape out another chip that hasn't had at least a basic level of ECAM testing (and obviously it should be much more). Emulation time should catch the vast majority of bugs as real PCIe devices are used against a design using speed bridges and the like. There's no excuse not to test. And frankly it boggles my mind that anyone would think that was a prudent way to do business. You can have every distro "just work" by doing it right, or you can have years of pain by doing it wrong. And too many still think the BSP hack it up model is the way to go. We ought to be dealing predominantly with the long tail of stuff that is using obviously busted IP that was already baked. We can use quirks for that. But then they need to go away and be replaced with real ECAM that works on future platforms. > I'm sorry for my bitter tone, but I think this time could and should > have been spent better - I doubt it managed to push us in any > significant way towards wide fully-standard compliant PCIE IP > adoption. Truthfully there will be some parts of the Arm story that will be unpleasant footnotes in the historical telling. How we haven't moved the third party IP vendors faster is a significant one. I think we have a chance to finally change that now that Arm is gaining traction. I am very sad that some of the early comers who tried to do the right thing had to deal with the state of third party IP at the time. Jon.
