Re: Linux regressions report for mainline [2023-10-29]

[Huacai Chen]

Hi, Linus,

On Mon, Oct 30, 2023 at 10:53 AM Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> On Sun, 29 Oct 2023 at 16:18, Huacai Chen <chenhuacai@xxxxxxxxxx> wrote:
> >
> > We are investigating and hope the simpledrm problem can be fixed in
> > some days [1],
>
> I don't understand your "some days".  The original report was two+
> weeks ago, and the link you point to does not seem to have a suggested
> patch for the problem either.
>
> So where does the "some days" come from?
>
> The WHOLE POINT of the "no regressions" rule - and the reason it came
> to be in the first place - was that we used to have these endless "one
> step forward, two steps back" things with suspend/resume in
> particular, where people fixed one device, but then broke a random
> number of other devices, and kept saying " but I fixed something".
>
> No. If you broke something else, YOU DIDN'T FIX ANYTHING AT ALL.
>
> This is literally why we have that "no regressions" rule. No amount of
> "but it's a fix" is valid at all if something else breaks. And no
> amount of "I will fix the thing I broke in the future"  is valid
> either.
>
> If you don't have a fix for it, it's broken. And I don't even see a
> *suggested* fix for people to try out.
>
> > and the blank screen seems not a very harmful problem
> > (maybe I'm wrong but I think most of people are using GUI now). So,
> > can we keep the commit 60aebc9559492c at this time?
>
> At least the email from Evan Preston seems to imply it's a blank
> screen that doesn't go away.
>
>   "Upgrading from Linux 6.4.12 to 6.5 and later results in only a
> blank screen after boot and a rapidly flashing device-access-status
> indicator"
>
> And no, "most people using GUI" doesn't matter. You are supposed to be
> able to upgrade your working kernel, and it's supposed to keep
> working. That's *important*, because it's really really important that
> people *trust* that they can upgrade the kernel and not end up with
> something non-working, because that's how people then dare do kernel
> updates and dare test new kernels.
>
> If people then stop testing new kernels because they think new kernels
> might break their setup, we have lost something truly important.
>
> And yes, there are always exceptions. At some point, devices are just
> too old legacy and there is no way of testing. Or we've had some
> interface that was *so* mis-designed that it was a fundamental
> security issue or something like that.
>
> But no, this does not seem to be one of those issues.
>
> Now, I'm not going to revert it just before releasing v6.6 (which I
> have locally tagged, but not pushed out yet). And I'll have the merge
> window for 6.7 opening tomorrow. But if this is not fixed by -rc1,
> we'll just revert it.
OK, I know. I will try my best. Thank you.

Huacai

>
>                     Linus