[PATCH] docs/platform: thead-c9xx: Improve the documentation

Guo Ren guoren at kernel.org
Fri Aug 11 17:15:34 PDT 2023


On Sat, Aug 12, 2023 at 8:07 AM Guo Ren <guoren at kernel.org> wrote:
>
> On Sat, Aug 12, 2023 at 1:57 AM Conor Dooley <conor at kernel.org> wrote:
> >
> > On Fri, Aug 11, 2023 at 12:33:32AM +0800, Jisheng Zhang wrote:
> > > On Tue, Aug 08, 2023 at 09:29:58AM -0400, guoren at kernel.org wrote:
> > > > From: Guo Ren <guoren at linux.alibaba.com>
> >
> > > > +T-HEAD Fdt Reset Driver Introduction
> > > > +------------------------------------
> > > > +
> > > > +Every T-HEAD CPU provides a reset control signal and reset address signals.
> > > > + - Reset address signal determines CPU where to start up.
> > > > + - Reset control signal releases CPU from reset state and begins to execute
> > > > +   at reset address.
> > > > +
> > > > +Many vendors would gather these signals into SoC control registers. These
> > > > +register designs are similar but with different base addresses and bits
> > > > +definitions. We only provide standard opensbi, Linux binaries, and jtag gdbinit
> > > > +script to simplify Linux booting at the FPGA stage. The fdt reset driver helps
> > > > +users bring up their SMP system quickly with the below settings:
> > >
> > > +DT maintainers and DT list.
> > >
> > > I can submit a dt-binding for this if DT maintainers agree with below
> > > properties. Could you please help review?
> >
> > I already reviewed this once & nothing has improved.
> > In fact, things have gotten worse IMO with this "using-csr-reset" that I
> > don't think existed in the original iteration that I saw.
> > I did see things getting better with the use of standard stuff like
> > "reg" in our earlier discussion which I don't see here.
> It's not a patch to improve the implementation and we don't make a
> deal in that discussion. This patch improves the document because the
> previous doc didn't describe the whole thing about the
> thead,reset-sample driver.
>
> > What is the point in carrying out any further review if things will be
> > flat out ignored?
I think the critical problem is JC objects to the whole of this
existing driver,  so any improvement is meaningless for the current.
Your naming advice is okay for me, but it does not relate to this
patch.

>
> >
> > Thanks,
> > Conor.
> >
> > > > +
> > > > + - entry-reg:
> > > > +   The base address to store reset address value
> > > > +
> > > > + - entry-cnt:
> > > > +   The numbers of entry-reg, all of them set the same reset address
> > > > +
> > > > + - control-reg:
> > > > +   The base address to reset the controller
> > > > +
> > > > + - control-val:
> > > > +   Write which bits of control-reg for booting
> > > > +
> > > > + - csr-copy:
> > > > +   This array determines which csrs to copy from primary hart to the
> > > > +   secondary harts, which are set in sequence from left to right. The
> > > > +   secondary harts should keep the same setting as the primary hart.
> > > > +   These settings are also the first part of the bootup instructions
> > > > +   for secondary harts.
> > > > +
> > > > + - using-csr-reset:
> > > > +   A legacy reset controller for the SMP system, but abandoned in the
> > > > +   latest T-HEAD processors.
> >
>
>
> --
> Best Regards
>  Guo Ren



-- 
Best Regards
 Guo Ren



More information about the opensbi mailing list