On Wed, Oct 26, 2016 at 10:09:07PM +0000, Leo Li wrote: > > > -----Original Message----- > > From: Mark Rutland [mailto:mark.rutl...@arm.com] > > Sent: Wednesday, October 26, 2016 5:31 AM > > To: M.H. Lian <minghuan.l...@nxp.com> > > Cc: linux-arm-ker...@lists.infradead.org; linux-kernel@vger.kernel.org; > > devicet...@vger.kernel.org; Marc Zyngier <marc.zyng...@arm.com>; Stuart > > Yoder <stuart.yo...@nxp.com>; Leo Li <leoyang...@nxp.com>; Scott Wood > > <scott.w...@nxp.com>; Shawn Guo <shawn...@kernel.org>; Mingkai Hu > > <mingkai...@nxp.com> > > Subject: Re: [PATCH 1/6] dt/bindings: adjust bindings for Layerscape SCFG > > MSI > > > > On Tue, Oct 25, 2016 at 08:35:40PM +0800, Minghuan Lian wrote:
> > > -- compatible: should be "fsl,<soc-name>-msi" to identify > > > - Layerscape PCIe MSI controller block such as: > > > - "fsl,1s1021a-msi" > > > - "fsl,1s1043a-msi" > > > +- compatible: should be "fsl,ls-scfg-msi" > > > > This breaks old DTBs, and throws away information which you describe above > > as > > valuable. So another NAK for that. > > I agree with you that we should maintain the backward compatibility. > But on the other hand, I just found that there is a silly typo in the > original binding that "ls" is wrongly spelled as "1s" and they look > too close to be noticed in previous patch reviews. :( Sure, that's annoying, but we're stuck with it. > The driver and all the DTSes used the binding with the typo which > covered up the problem. So even if we want to keep the > "fsl,<soc-name>-msi" binding, we probably want to fix the typo, right? > And that breaks the backward compatibility too. Regardless of what we do, we should *not* break compatibility. The old strings must remain. However, we can *add* correctly-spelt variants, and mark the existing strings as deprecated (in both the binding and driver). The in-kernel dts can be updated to use the correctly-spelt strings. Thanks, Mark.
