Re: [PATCH v19 2/9] usb: dwc3: core: Access XHCI address space temporarily to read port info

From: Bjorn Andersson
Date: Fri Apr 05 2024 - 15:27:27 EST


On Fri, Apr 05, 2024 at 06:43:56AM +0200, Greg Kroah-Hartman wrote:
> On Thu, Apr 04, 2024 at 06:25:48PM -0700, Bjorn Andersson wrote:
> > On Thu, Apr 04, 2024 at 02:58:29PM +0200, Greg Kroah-Hartman wrote:
> > > On Thu, Apr 04, 2024 at 10:07:27AM +0200, Krzysztof Kozlowski wrote:
> > > > On 04/04/2024 09:21, Johan Hovold wrote:
> > > > > On Thu, Apr 04, 2024 at 10:42:22AM +0530, Krishna Kurapati wrote:
> > > > >
> > > > >> +static int dwc3_get_num_ports(struct dwc3 *dwc)
> > > > >> +{
> > > > >> + void __iomem *base;
> > > > >> + u8 major_revision;
> > > > >> + u32 offset;
> > > > >> + u32 val;
> > > > >> +
> > > > >> + /*
> > > > >> + * Remap xHCI address space to access XHCI ext cap regs since it is
> > > > >> + * needed to get information on number of ports present.
> > > > >> + */
> > > > >> + base = ioremap(dwc->xhci_resources[0].start,
> > > > >> + resource_size(&dwc->xhci_resources[0]));
> > > > >> + if (!base)
> > > > >> + return PTR_ERR(base);
> > > > >
> > > > > This is obviously still broken. You need to update the return value as
> > > > > well.
> > > > >
> > > > > Fix in v20.
> > > >
> > > > If one patchset reaches 20 versions, I think it is time to stop and
> > > > really think from the beginning, why issues keep appearing and reviewers
> > > > are still not happy.
> > > >
> > > > Maybe you did not perform extensive internal review, which you are
> > > > encouraged to by your own internal policies, AFAIR. Before posting next
> > > > version, please really get some internal review first.
> > >
> > > Also get those internal reviewers to sign-off on the commits and have
> > > that show up when you post them next. That way they are also
> > > responsible for this patchset, it's not fair that they are making you do
> > > all the work here :)
> > >
> >
> > I like this idea and I'm open to us changing our way of handling this.
> >
> > But unless such internal review brings significant input to the
> > development I'd say a s-o-b would take the credit from the actual
> > author.
>
> It does not do that at all. It provides proof that someone else has
> reviewed it and agrees with it. Think of it as a "path of blame" for
> when things go bad (i.e. there is a bug in the submission.) Putting
> your name on it makes you take responsibility if that happens.
>

Right, this is why I like your idea.

But as s-o-b either builds a trail of who handled the patch, or reflects
that it was co-authored by multiple people, I don't think either one
properly reflects reality.

> > We've discussed a few times about carrying Reviewed-by et al from the
> > internal reviews, but as maintainer I dislike this because I'd have no
> > way to know if a r-b on vN means the patch was reviewed, or if it was
> > just "accidentally" carried from v(N-1).
> > But it might be worth this risk, is this something you think would be
> > appropriate?
>
> For some companies we REQUIRE this to happen due to low-quality
> submissions and waste of reviewer's time. Based on the track record
> here for some of these patchsets, hopefully it doesn't become a
> requirement for this company as well :)
>

Interesting, I was under the impression that we (maintainers) didn't
want such internally originating tags.

If that's not the case, then I'd be happy to adjust our internal
guidelines.

Regards,
Bjorn