Thanks, Kyosti, sounds like you're on top of it :-) ron
On Mon, Dec 16, 2013 at 9:17 PM, Kyösti Mälkki <[email protected]> wrote: > On 12/16/2013 10:35 PM, ron minnich wrote: >> >> On Fri, Dec 13, 2013 at 2:29 AM, Kyösti Mälkki <[email protected]> >> wrote: >> >>> Yet we have had commit 032c23db for 5 months: >> >> >> which may mean, only, that the commit broke some things and nobody hit >> those things until 5 months later? >> >> Which is not at all unusual with a change of this type. It's why we >> prefer that commits that are this far-reaching come with some amount >> of testing. >> That patch changed 7 mainboards; which of them were tested? >> > > Before merge, test on kontron/986-lcd-m as was recorded here: > http://review.coreboot.org/#/c/3584/ > > Also lenovo x60 and t60 boards have been often built from master during the > last 5 months. > > > >>> I remember a week or so after this was merged you made that comment about >>> i945 on a related change. I requested literature reference or a test case >>> to >>> see if I should revert. I got neither and the revert never took place. >> >> >> It pays to listen to Stefan on matters such as these :-) >> >> There are at least two reasons that your request might not have been >> satisfiable. >> - the public docs and the hardware disagree (very common) >> - the public docs and the NDA docs disagree (this is very common) >> and the vendor knows it (also really common) >> >>> Until you are more specific on your statement, I am reading it as >>> follows: >>> >>> Stefan added 'select MMCONF_SUPPORT_DEFAULT' on a mainboard with i945 >>> and the board did not boot. >> >> >> And sometimes that's about as good a diagnosis as you can get. >> >> Expecting anything more is not always realistic. That's what makes >> firmware so hard, sometimes. >> >> Meanwhile, we have a commit that broke some hardware. What do you want >> to do about it? I agree with Aaron, things might need to be tweaked, >> but ... >> who's got that old hardware, and the time to do it? Do you have a >> board of that ilk and the time to figure it out? >> >> How do you intend to resolve the problem caused by this commit? > > > The process of deciding if i945 needs a fix has begun. > > As you may notice, the first thing was to try to find out if the original > statement is reliable, backuped up by any documentation, or if the statement > was made based on runs on some particular platform. > > So far no data from current and known codebase builds supports the statement > that some PCI devices would not be accessible over MMCONF on platform with > i945- > > From a fairly recent codebase we see PCI MMCONF setup for i945 had two flaws > in design: a) There are PCI configuration access before MMCONF is enabled > which need to be forced to use IO and b) With MMCONF_SUPPORT_DEFAULT, PCI > configuration access in early ramstage would use IO instead and fail to > access registers in range 0x100-0xfff. There is reason to believe i945 > development platform had same problems, which questions the reliability of > the made conclusions. > > > Kyösti > -- coreboot mailing list: [email protected] http://www.coreboot.org/mailman/listinfo/coreboot
