From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt Subject: Re: [PATCH v4 19/23] drivers/fsi: Add GPIO based FSI master Date: Mon, 10 Apr 2017 07:55:37 +1000 Message-ID: <1491774937.4166.198.camel@au1.ibm.com> References: <20170329174340.89109-1-cbostic@linux.vnet.ibm.com> <20170329174340.89109-20-cbostic@linux.vnet.ibm.com> <0e1bcf3a-e8d7-9f50-bdf7-2a1e7466665b@linux.vnet.ibm.com> <1490907014.3177.207.camel@kernel.crashing.org> <93b21624-11fc-b71b-aa78-6cb4371c87ae@linux.vnet.ibm.com> <1491344360.4166.68.camel@kernel.crashing.org> <5344146a-f450-7959-4688-a83ee022574b@linux.vnet.ibm.com> <1491774092.4166.195.camel@kernel.crashing.org> <1491774835.4166.197.camel@au1.ibm.com> Reply-To: benh-8fk3Idey6ehBDgjK7y7TUQ@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <1491774835.4166.197.camel-8fk3Idey6ehBDgjK7y7TUQ@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Christopher Bostic , Joel Stanley Cc: Rob Herring , Mark Rutland , Russell King , rostedt-nx8X9YLhiw1AfugRpC6u6w@public.gmane.org, mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, Greg KH , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Linux Kernel Mailing List , Andrew Jeffery , Alistair Popple , "Edward A . James" , Jeremy Kerr List-Id: devicetree@vger.kernel.org On Mon, 2017-04-10 at 07:53 +1000, Benjamin Herrenschmidt wrote: > FYI. pdbg in userspace operates without any  delays in practice, the > overhead between the various load/store instructions seems > sufficient. > > The only delay that's needed is when going through the FSI2PIB (to do > SCOMs) where it seems like back-2-back accesses can be problematic. Note: This isn't an objection to merging the patches. We can look at doing an improved backend later. Cheers, Ben. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html