From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Subject: [V2,1/5] usb: serial: f81534: add high baud rate support From: Johan Hovold Message-Id: <20180110092740.GX11344@localhost> Date: Wed, 10 Jan 2018 10:27:40 +0100 To: "Ji-Ze Hong \(Peter Hong\)" Cc: Johan Hovold , gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, peter_hong@fintek.com.tw, "Ji-Ze Hong \(Peter Hong\)" List-ID: T24gV2VkLCBKYW4gMTAsIDIwMTggYXQgMDU6MTY6MDFQTSArMDgwMCwgSmktWmUgSG9uZyAoUGV0 ZXIgSG9uZykgd3JvdGU6Cj4gSGkgSm9oYW4sCj4gCj4gSm9oYW4gSG92b2xkIOaWvCAyMDE4LzEv MTAg5LiL5Y2IIDA0OjQ5IOWvq+mBkzoKPiA+PiBOb3JtYWxseSwgdGhlIGNvbW11bmljYXRpb24g d2l0aCBGODE1MzQgZXAwIHdpbGwgdGFrZSBsZXNzIHRoYW4gMSBzZWMKPiA+PiAoZXZlbiBvbmx5 IHNvbWUgbWlsbGlzZWNvbmRzKSwgYnV0IEl0IG1heWJlIHRha2UgbXVjaCBsb25nIHRpbWUgd2l0 aAo+ID4+IGh1Z2UgbG9hZGluZyB3aXRoIFVBUlQgZnVuY3Rpb25hbC4KPiA+Pgo+ID4+IFdlIGhh ZCB0ZXN0ZWQgaXQgb24gQnVybkluVGVzdCwgNCBwb3J0cyB3aXRoIDkyMTYwMGJwcyArIE1TUiBz dGF0dXMKPiA+PiBjaGVjayB0byBwZXJmb3JtIGh1Z2UgbG9hZGluZyB0ZXN0LiBUaGUgd29yc3Qg Y2FzZSB0byByZWFkIE1TUiByZWdpc3Rlcgo+ID4+IHZpYSBlcDAgd2lsbCB0YWtlIDE1fjE4IHNl Y29uZHMuIFNvIFdlJ2xsIHN0aWxsIHJlbWFpbiB0aGUgbWF4IHdhaXRpbmcKPiA+PiB0aW1lIGZv ciBhY2Nlc3MgZXAwIHdpdGggMngxMD0yMHMgaW4gaGlnaCBiYXVkIHJhdGUgbW9kZS4KPiA+IAo+ ID4gV293LCB0aGF0J3MgdW5mb3J0dW5hdGUuIEJ1dCBub3RlIHRoYXQgeW91ciBwYXRjaCBvbmx5 IGRvdWJsZXMgdGhlCj4gPiB0aW1lb3V0IHRvIDIwMDAgbXMsIHRoYXQgaXMsIHR3byBzZWNvbmRz IGFuZCBub3QgdHdlbnR5Ogo+ID4gCj4gPiAtI2RlZmluZSBGODE1MzRfVVNCX1RJTUVPVVQgICAg ICAgICAgICAgMTAwMAo+ID4gKyNkZWZpbmUgRjgxNTM0X1VTQl9USU1FT1VUICAgICAgICAgICAg IDIwMDAKPiA+IAo+ID4gSWYgeW91IHJlYWxseSBpbnRlbmRlZCB0byBpbmNyZWFzZSB0aGlzIHRv IHR3ZW50eSBzZWNvbmRzLCB0aGVuIHBsZWFzZQo+ID4gZG8gc28gaW4gYSBzZXBhcmF0ZSAocHJl cGFyYXRvcnkpIHBhdGNoIHdoZXJlIHlvdSBkZXNjcmliZSB3aHkgdGhhdCBpcwo+ID4gbmVlZGVk IChlLmcuIHdoYXQgeW91IHdyb3RlIGFib3ZlKS4KPiAKPiBJbiBmODE1MzRfc2V0X3JlZ2lzdGVy KCkvZjgxNTM0X2dldF9yZWdpc3RlcigpLCBXZSdsbCB1c2UgYSB3aGlsZSBsb29wCj4gd2l0aCAx MCB0aW1lcyB0byBnZXQvc2V0IHJlZ2lzdGVyIGFuZCB0aGUgdGltZW91dCBpcyAxMDAwbXMuIFNv IHRoZQo+IHRvdGFsIG1pbmltdW0gcmV0cnkgdGltZW91dCBpcyAxMDAweDEwPTEwcy4KPiAKPiBC dXQgd2hlbiBpbnRyb2R1Y2luZyB0aGUgaGlnaCBiYXVkIHJhdGUgc3VwcG9ydCwgMTBzIGlzIG5v dCBlbm91Z2ggZm9yCj4gaGVhdmlseSBsb2FkaW5nLiBXZSBoYWQgdGVzdGVkIHRoZSBtaW5pbXVt IHJldHJ5IGlzIDE2fjE4cywgc28gd2UKPiBlbmxhcmdlIHRoZSBGODE1MzRfVVNCX1RJTUVPVVQg ZnJvbSAxMDAwIHRvIDIwMDAgYW5kIHRoZSB0b3RhbCBtaW5pbXVtCj4gcmV0cnkgdGltZW91dCBp cyAyMHMuCj4gCj4gU2hvdWxkIEkgc2VwYXJhdGUgaXQgYXMgMiBwYXRjaGVzPyBUaGlzIGlzc3Vl IGlzIGR1ZSB0byBpbnRyb2R1Y2luZwo+IGhpZ2ggYmF1ZCBwYXRjaC4KCkFoLCBzb3JyeS4gRm9y Z290IGFib3V0IHRoZSByZXRyaWVzLiBJbmNyZWFzaW5nIGl0IGFzIHBhcnQgb2YgdGhpcyBwYXRj aAppcyBmaW5lLgoKSm9oYW4KLS0tClRvIHVuc3Vic2NyaWJlIGZyb20gdGhpcyBsaXN0OiBzZW5k IHRoZSBsaW5lICJ1bnN1YnNjcmliZSBsaW51eC11c2IiIGluCnRoZSBib2R5IG9mIGEgbWVzc2Fn ZSB0byBtYWpvcmRvbW9Admdlci5rZXJuZWwub3JnCk1vcmUgbWFqb3Jkb21vIGluZm8gYXQgIGh0 dHA6Ly92Z2VyLmtlcm5lbC5vcmcvbWFqb3Jkb21vLWluZm8uaHRtbAo= From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965366AbeAJJ1v (ORCPT + 1 other); Wed, 10 Jan 2018 04:27:51 -0500 Received: from mail-lf0-f48.google.com ([209.85.215.48]:39840 "EHLO mail-lf0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965256AbeAJJ1p (ORCPT ); Wed, 10 Jan 2018 04:27:45 -0500 X-Google-Smtp-Source: ACJfBotGNjPqeF4FE8Sp0InkPdO5runiWs935UCNeummcrYuYXxgE2QSBmKh/KPSd97HdiV7To7ohg== Date: Wed, 10 Jan 2018 10:27:40 +0100 From: Johan Hovold To: "Ji-Ze Hong (Peter Hong)" Cc: Johan Hovold , gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, peter_hong@fintek.com.tw, "Ji-Ze Hong (Peter Hong)" Subject: Re: [PATCH V2 1/5] usb: serial: f81534: add high baud rate support Message-ID: <20180110092740.GX11344@localhost> References: <1515032961-29131-1-git-send-email-hpeter+linux_kernel@gmail.com> <20180109110841.GN11344@localhost> <18d4171a-1e1a-5476-dc9d-02a522cbf077@gmail.com> <20180110084914.GV11344@localhost> <3b594392-1b6d-f019-1e5f-3e3e3f87f7e8@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <3b594392-1b6d-f019-1e5f-3e3e3f87f7e8@gmail.com> User-Agent: Mutt/1.7.2 (2016-11-26) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On Wed, Jan 10, 2018 at 05:16:01PM +0800, Ji-Ze Hong (Peter Hong) wrote: > Hi Johan, > > Johan Hovold 於 2018/1/10 下午 04:49 寫道: > >> Normally, the communication with F81534 ep0 will take less than 1 sec > >> (even only some milliseconds), but It maybe take much long time with > >> huge loading with UART functional. > >> > >> We had tested it on BurnInTest, 4 ports with 921600bps + MSR status > >> check to perform huge loading test. The worst case to read MSR register > >> via ep0 will take 15~18 seconds. So We'll still remain the max waiting > >> time for access ep0 with 2x10=20s in high baud rate mode. > > > > Wow, that's unfortunate. But note that your patch only doubles the > > timeout to 2000 ms, that is, two seconds and not twenty: > > > > -#define F81534_USB_TIMEOUT 1000 > > +#define F81534_USB_TIMEOUT 2000 > > > > If you really intended to increase this to twenty seconds, then please > > do so in a separate (preparatory) patch where you describe why that is > > needed (e.g. what you wrote above). > > In f81534_set_register()/f81534_get_register(), We'll use a while loop > with 10 times to get/set register and the timeout is 1000ms. So the > total minimum retry timeout is 1000x10=10s. > > But when introducing the high baud rate support, 10s is not enough for > heavily loading. We had tested the minimum retry is 16~18s, so we > enlarge the F81534_USB_TIMEOUT from 1000 to 2000 and the total minimum > retry timeout is 20s. > > Should I separate it as 2 patches? This issue is due to introducing > high baud patch. Ah, sorry. Forgot about the retries. Increasing it as part of this patch is fine. Johan