From mboxrd@z Thu Jan 1 00:00:00 1970 From: benh@kernel.crashing.org (Benjamin Herrenschmidt) Date: Wed, 05 Apr 2017 08:19:20 +1000 Subject: [PATCH v4 19/23] drivers/fsi: Add GPIO based FSI master In-Reply-To: <93b21624-11fc-b71b-aa78-6cb4371c87ae@linux.vnet.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> Message-ID: <1491344360.4166.68.camel@kernel.crashing.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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. Cheers, Ben. 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: Wed, 05 Apr 2017 08:19:20 +1000 Message-ID: <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> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <93b21624-11fc-b71b-aa78-6cb4371c87ae@linux.vnet.ibm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Christopher Bostic , Joel Stanley Cc: Mark Rutland , devicetree@vger.kernel.org, Andrew Jeffery , Greg KH , Russell King , rostedt@goodmis.org, Linux Kernel Mailing List , Rob Herring , Jeremy Kerr , "Edward A . James" , Alistair Popple , mingo@redhat.com, linux-arm-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.org T24gVHVlLCAyMDE3LTA0LTA0IGF0IDEyOjMyIC0wNTAwLCBDaHJpc3RvcGhlciBCb3N0aWMgd3Jv dGU6Cj4gQWdyZWVkIHRoYXQgdGhlcmUgaXMgcm9vbSBmb3IgaW1wcm92ZW1lbnQuwqDCoCBJIGlu dGVuZCB0byBsb29rIGZ1cnRoZXLCoAo+IGludG8geW91ciBzdWdnZXN0aW9ucyBmcm9tIGhlcmUg YW5kIG91ciBwcml2YXRlIGNvbnZlcnNhdGlvbiBvbiB0aGXCoAo+IG1hdHRlciBhbmQgbWFrZSBj aGFuZ2VzIGFzIGFwcHJvcHJpYXRlLsKgIEkgaGF2ZSBhbiBvcGVuIGlzc3VlIHRvIHRyYWNrwqAK PiB0aGlzLsKgIEFzIGl0IGV4aXN0cyBpbiB0aGlzIHBhdGNoIHJlYWRzL3dyaXRlcyBmcm9tIG1h c3RlciB0byBzbGF2ZcKgCj4gZnVuZGFtZW50YWxseSB3b3JrLsKgwqAKCk15IHVuZGVyc3RhbmRp bmcgaXMgdGhleSAic2VlbSB0byB3b3JrIGlmIHlvdSBnZXQgbHVja3kgd2l0aCB0aGUgdGltaW5n CmFuZCBmYWxsIGFwYXJ0IHVuZGVyIGxvYWQiLiBPciBkaWQgSSBoZWFyIHdyb25nID8KCj4gIEdp dmVuIHRoZSBwZXJ2YXNpdmVuZXNzIGFuZCB0aW1lIHRvIGZ1bGx5IGV2YWx1YXRlwqAKPiBhbmQg dGVzdCBhbnkgcHJvdG9jb2wgdXBkYXRlcyBJIGludGVuZCBhZGRyZXNzIHRoaXMgaW4gdGhlIG5l YXIgZnV0dXJlwqAKPiB3aXRoIGEgc2VwYXJhdGUgZm9sbG93IG9uIHBhdGNoLgoKUGxlYXNlIHRy eSB0aGUgc2ltcGxlIGNoYW5nZSBJIHByb3Bvc2VkIGluIG15IGVtYWlsLiBJdCdzIGEgNCBvciA1 CmxpbmVzIGNoYW5nZSBtYXggdG8geW91ciBjbG9ja190b2dnbGUgZnVuY3Rpb24gYW5kIGhvdyBp dCdzIGNhbGxlZCBpbgpzZW5kIGFuZCByZWNlaXZlLiBJdCBzaG91bGQgYmUgdHJpdmlhbCB0byBj aGVjayBpZiB0aGluZ3Mgc3RpbGwgInNlZW0KdG8gd29yayIgdG8gYmVnaW4gd2l0aC4KCkRvIHlv dSBoYXZlIHNvbWUga2luZCBvZiB0ZXN0IG1lY2hhbmlzbSB0aGF0IGhhbW1lcnMgdGhlIEZTSQpj b250aW51b3VzbHkgPyBTdWNoIGFzIGRvaW5nIGEgc2VyaWVzIG9mwqBwdXRtZW1wcm9jL2dldG1l bXByb2MgJgpjaGVja2luZyB0aGUgdmFsdWVzID8KClRoZW4geW91IGNhbiBydW4gdGhhdCB3aGls ZSBoYW1tZXJpbmcgdGhlIExQQyBidXMgYW5kIGdlbmVyYWxseSBwdXR0aW5nCnRoZSBCTUMgdW5k ZXIgbG9hZCBhbmQgeW91J2xsIHF1aWNrbHkgc2VlIGlmIGl0J3MgcmVsaWFibGUgb3Igbm90LgoK Q2hlZXJzLApCZW4uCgoKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX18KbGludXgtYXJtLWtlcm5lbCBtYWlsaW5nIGxpc3QKbGludXgtYXJtLWtlcm5lbEBsaXN0 cy5pbmZyYWRlYWQub3JnCmh0dHA6Ly9saXN0cy5pbmZyYWRlYWQub3JnL21haWxtYW4vbGlzdGlu Zm8vbGludXgtYXJtLWtlcm5lbAo= From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754913AbdDDWXF (ORCPT ); Tue, 4 Apr 2017 18:23:05 -0400 Received: from gate.crashing.org ([63.228.1.57]:33478 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752997AbdDDWXE (ORCPT ); Tue, 4 Apr 2017 18:23:04 -0400 Message-ID: <1491344360.4166.68.camel@kernel.crashing.org> Subject: Re: [PATCH v4 19/23] drivers/fsi: Add GPIO based FSI master From: Benjamin Herrenschmidt To: Christopher Bostic , Joel Stanley Cc: Rob Herring , Mark Rutland , Russell King , rostedt@goodmis.org, mingo@redhat.com, Greg KH , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Linux Kernel Mailing List , Andrew Jeffery , Alistair Popple , "Edward A . James" , Jeremy Kerr Date: Wed, 05 Apr 2017 08:19:20 +1000 In-Reply-To: <93b21624-11fc-b71b-aa78-6cb4371c87ae@linux.vnet.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> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6 (3.22.6-1.fc25) Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Cheers, Ben.