From mboxrd@z Thu Jan 1 00:00:00 1970 From: cbostic@linux.vnet.ibm.com (Christopher Bostic) Date: Tue, 4 Apr 2017 20:24:33 -0500 Subject: [PATCH v4 19/23] drivers/fsi: Add GPIO based FSI master In-Reply-To: <1491344360.4166.68.camel@kernel.crashing.org> 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> Message-ID: <6fa53e69-924d-cd0f-9489-0f6ac6f5595e@linux.vnet.ibm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 4/4/17 5:19 PM, Benjamin Herrenschmidt wrote: > On Tue, 2017-04-04 at 12:32 -0500, Christopher Bostic wrote: >> Agreed that there is room for improvement. I intend to look further >> into your suggestions from here and our private conversation on the >> matter and make changes as appropriate. I have an open issue to track >> this. As it exists in this patch reads/writes from master to slave >> fundamentally work. > My understanding is they "seem to work if you get lucky with the timing > and fall apart under load". Or did I hear wrong ? > >> Given the pervasiveness and time to fully evaluate >> and test any protocol updates I intend address this in the near future >> with a separate follow on patch. > Please try the simple change I proposed in my email. It's a 4 or 5 > lines change max to your clock_toggle function and how it's called in > send and receive. It should be trivial to check if things still "seem > to work" to begin with. > > Do you have some kind of test mechanism that hammers the FSI > continuously ? Such as doing a series of putmemproc/getmemproc & > checking the values ? > > Then you can run that while hammering the LPC bus and generally putting > the BMC under load and you'll quickly see if it's reliable or not. Hi Ben, I do now have a mechanism that puts the bus under heavy load. I'll look into your changes tomorrow. Thanks, Chris > > Cheers, > Ben. >