From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Gunthorpe Subject: Re: [PATCH rdma-next V2 6/6] RDMA/core: Unify style of IOCTL commands Date: Thu, 1 Sep 2016 10:46:24 -0600 Message-ID: <20160901164624.GC6479@obsidianresearch.com> References: <1471987907-6336-1-git-send-email-leon@kernel.org> <1471987907-6336-7-git-send-email-leon@kernel.org> <1472738739.16467.8.camel@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: <1472738739.16467.8.camel-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Dalessandro, Dennis" Cc: "leon-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org" , "dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org" , "matanb-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org" , "linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org" , "haggaie-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org" List-Id: linux-rdma@vger.kernel.org On Thu, Sep 01, 2016 at 02:05:44PM +0000, Dalessandro, Dennis wrote: > > +/* allocate HFI and context */ > > +#define HFI1_CMD_ASSIGN_CTXT     (HFI1_CMD_BASE + 0x01) > > This is a minor issue, but the problem here is when we build PSM > against this kernel it will no longer work for older kernels because > the value of HFI1_CMD_ASSIGN_CTXT has changed where as it used to be 1. > Right now PSM is backwards compatible, this breaks that compatibility. What? Someone renumberd an ioctl? When? Why? How? Was this ioctl ever in a mainline non-staging kernel? If not, too bad, deal with it in your user space.. If yes, can we revert the renumbering? Why was that even done?? > So while no one uses the __NUM() macro directly it lets us not change > the PSM command values. Can we put that part back and keep the command > values unchanged? Please no, do not do crazy subtle things like this. If the ioctl has two valid numbers then you need two entries in the ioctl file. Jason -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html