From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 33AEDC433DF for ; Fri, 3 Jul 2020 07:43:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 13CE2207DA for ; Fri, 3 Jul 2020 07:43:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593762231; bh=C8iFxt0NgFIvOHyJ2HTE6mwHa37qTKVYpAmsMlM4Jjk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=0qMfpFe4ppB9YikJ0EWWmUTNkrH1gETSXzQD/m3Tmaxzpl8ofY4gCLRh7Y5ByvZ7X yzHAstMmgPjncaO/anlp4MKfWYCBPGk5rnEW/JxfJxGHl0hwFIKMc1l5NL+6c+69K+ vYNzw0+i3VNAf3l2S6ZJ92TUN+r8EyYsbDkGl+v8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726410AbgGCHnu (ORCPT ); Fri, 3 Jul 2020 03:43:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:32936 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725984AbgGCHnt (ORCPT ); Fri, 3 Jul 2020 03:43:49 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D9BD6206B6; Fri, 3 Jul 2020 07:43:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593762229; bh=C8iFxt0NgFIvOHyJ2HTE6mwHa37qTKVYpAmsMlM4Jjk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=08HzS+QRvQx8wNaw4OP+PFJrrhVygi5THG75ygrS4YzeTcGPVz9EkCn+C6yJagtOl YLdSMZ+vzBqq1mK5Bi4Z69mkyuZcyTSbvjFMsYF8GE1fEAC2qvOycPpDCXtICVhIof hDBMuTx4jIVyOoVzsTRMSaAEjHmTZ0MqVTUWi9Pg= Date: Fri, 3 Jul 2020 09:43:53 +0200 From: Greg KH To: Minas Harutyunyan Cc: Lee Jones , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "linux-usb@vger.kernel.org" , Ben Dooks Subject: Re: [PATCH 11/30] usb: dwc2: gadget: Avoid pointless read of EP control register Message-ID: <20200703074353.GA2391671@kroah.com> References: <20200702144625.2533530-1-lee.jones@linaro.org> <20200702144625.2533530-12-lee.jones@linaro.org> <20200703072926.GA2322133@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Fri, Jul 03, 2020 at 07:38:16AM +0000, Minas Harutyunyan wrote: > Hi, > > On 7/3/2020 11:29 AM, Greg KH wrote: > > On Thu, Jul 02, 2020 at 03:46:06PM +0100, Lee Jones wrote: > >> Commit ec1f9d9f01384 ("usb: dwc2: gadget: parity fix in isochronous mode") moved > >> these checks to dwc2_hsotg_change_ep_iso_parity() back in 2015. The assigned > >> value hasn't been read back since. Let's remove the unnecessary H/W read. > >> > >> Fixes the following W=1 warning: > >> > >> drivers/usb/dwc2/gadget.c: In function ‘dwc2_hsotg_epint’: > >> drivers/usb/dwc2/gadget.c:2981:6: warning: variable ‘ctrl’ set but not used [-Wunused-but-set-variable] > >> 2981 | u32 ctrl; > >> | ^~~~ > >> > >> Cc: Minas Harutyunyan > >> Cc: Ben Dooks > >> Signed-off-by: Lee Jones > >> --- > >> drivers/usb/dwc2/gadget.c | 2 -- > >> 1 file changed, 2 deletions(-) > >> > >> diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c > >> index 116e6175c7a48..fa07e3fcb8841 100644 > >> --- a/drivers/usb/dwc2/gadget.c > >> +++ b/drivers/usb/dwc2/gadget.c > >> @@ -2975,10 +2975,8 @@ static void dwc2_hsotg_epint(struct dwc2_hsotg *hsotg, unsigned int idx, > >> u32 epctl_reg = dir_in ? DIEPCTL(idx) : DOEPCTL(idx); > >> u32 epsiz_reg = dir_in ? DIEPTSIZ(idx) : DOEPTSIZ(idx); > >> u32 ints; > >> - u32 ctrl; > >> > >> ints = dwc2_gadget_read_ep_interrupts(hsotg, idx, dir_in); > >> - ctrl = dwc2_readl(hsotg, epctl_reg); > > > > As you know, lots of hardware requires reads to happen to do things, so > > are you sure it is safe to remove this read call? > > > > Greg, yes, it's Ok to remove this unnecessary read which remained from > previous implementations. Great, thanks for confirming! greg k-h From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B5653C433E0 for ; Fri, 3 Jul 2020 07:45:10 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 86B27206B6 for ; Fri, 3 Jul 2020 07:45:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="BpPdTwrm"; 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charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org T24gRnJpLCBKdWwgMDMsIDIwMjAgYXQgMDc6Mzg6MTZBTSArMDAwMCwgTWluYXMgSGFydXR5dW55 YW4gd3JvdGU6Cj4gSGksCj4gCj4gT24gNy8zLzIwMjAgMTE6MjkgQU0sIEdyZWcgS0ggd3JvdGU6 Cj4gPiBPbiBUaHUsIEp1bCAwMiwgMjAyMCBhdCAwMzo0NjowNlBNICswMTAwLCBMZWUgSm9uZXMg d3JvdGU6Cj4gPj4gQ29tbWl0IGVjMWY5ZDlmMDEzODQgKCJ1c2I6IGR3YzI6IGdhZGdldDogcGFy aXR5IGZpeCBpbiBpc29jaHJvbm91cyBtb2RlIikgbW92ZWQKPiA+PiB0aGVzZSBjaGVja3MgdG8g ZHdjMl9oc290Z19jaGFuZ2VfZXBfaXNvX3Bhcml0eSgpIGJhY2sgaW4gMjAxNS4gIFRoZSBhc3Np Z25lZAo+ID4+IHZhbHVlIGhhc24ndCBiZWVuIHJlYWQgYmFjayBzaW5jZS4gIExldCdzIHJlbW92 ZSB0aGUgdW5uZWNlc3NhcnkgSC9XIHJlYWQuCj4gPj4KPiA+PiBGaXhlcyB0aGUgZm9sbG93aW5n IFc9MSB3YXJuaW5nOgo+ID4+Cj4gPj4gICBkcml2ZXJzL3VzYi9kd2MyL2dhZGdldC5jOiBJbiBm dW5jdGlvbiDigJhkd2MyX2hzb3RnX2VwaW504oCZOgo+ID4+ICAgZHJpdmVycy91c2IvZHdjMi9n YWRnZXQuYzoyOTgxOjY6IHdhcm5pbmc6IHZhcmlhYmxlIOKAmGN0cmzigJkgc2V0IGJ1dCBub3Qg dXNlZCBbLVd1bnVzZWQtYnV0LXNldC12YXJpYWJsZV0KPiA+PiAgIDI5ODEgfCB1MzIgY3RybDsK PiA+PiAgIHwgXn5+fgo+ID4+Cj4gPj4gQ2M6IE1pbmFzIEhhcnV0eXVueWFuIDxobWluYXNAc3lu b3BzeXMuY29tPgo+ID4+IENjOiBCZW4gRG9va3MgPGJlbkBzaW10ZWMuY28udWs+Cj4gPj4gU2ln bmVkLW9mZi1ieTogTGVlIEpvbmVzIDxsZWUuam9uZXNAbGluYXJvLm9yZz4KPiA+PiAtLS0KPiA+ PiAgIGRyaXZlcnMvdXNiL2R3YzIvZ2FkZ2V0LmMgfCAyIC0tCj4gPj4gICAxIGZpbGUgY2hhbmdl ZCwgMiBkZWxldGlvbnMoLSkKPiA+Pgo+ID4+IGRpZmYgLS1naXQgYS9kcml2ZXJzL3VzYi9kd2My L2dhZGdldC5jIGIvZHJpdmVycy91c2IvZHdjMi9nYWRnZXQuYwo+ID4+IGluZGV4IDExNmU2MTc1 YzdhNDguLmZhMDdlM2ZjYjg4NDEgMTAwNjQ0Cj4gPj4gLS0tIGEvZHJpdmVycy91c2IvZHdjMi9n YWRnZXQuYwo+ID4+ICsrKyBiL2RyaXZlcnMvdXNiL2R3YzIvZ2FkZ2V0LmMKPiA+PiBAQCAtMjk3 NSwxMCArMjk3NSw4IEBAIHN0YXRpYyB2b2lkIGR3YzJfaHNvdGdfZXBpbnQoc3RydWN0IGR3YzJf aHNvdGcgKmhzb3RnLCB1bnNpZ25lZCBpbnQgaWR4LAo+ID4+ICAgCXUzMiBlcGN0bF9yZWcgPSBk aXJfaW4gPyBESUVQQ1RMKGlkeCkgOiBET0VQQ1RMKGlkeCk7Cj4gPj4gICAJdTMyIGVwc2l6X3Jl ZyA9IGRpcl9pbiA/IERJRVBUU0laKGlkeCkgOiBET0VQVFNJWihpZHgpOwo+ID4+ICAgCXUzMiBp bnRzOwo+ID4+IC0JdTMyIGN0cmw7Cj4gPj4gICAKPiA+PiAgIAlpbnRzID0gZHdjMl9nYWRnZXRf cmVhZF9lcF9pbnRlcnJ1cHRzKGhzb3RnLCBpZHgsIGRpcl9pbik7Cj4gPj4gLQljdHJsID0gZHdj Ml9yZWFkbChoc290ZywgZXBjdGxfcmVnKTsKPiA+IAo+ID4gQXMgeW91IGtub3csIGxvdHMgb2Yg aGFyZHdhcmUgcmVxdWlyZXMgcmVhZHMgdG8gaGFwcGVuIHRvIGRvIHRoaW5ncywgc28KPiA+IGFy ZSB5b3Ugc3VyZSBpdCBpcyBzYWZlIHRvIHJlbW92ZSB0aGlzIHJlYWQgY2FsbD8KPiA+IAo+IAo+ IEdyZWcsIHllcywgaXQncyBPayB0byByZW1vdmUgdGhpcyB1bm5lY2Vzc2FyeSByZWFkIHdoaWNo IHJlbWFpbmVkIGZyb20gCj4gcHJldmlvdXMgaW1wbGVtZW50YXRpb25zLgoKR3JlYXQsIHRoYW5r cyBmb3IgY29uZmlybWluZyEKCmdyZWcgay1oCgpfX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fXwpsaW51eC1hcm0ta2VybmVsIG1haWxpbmcgbGlzdApsaW51eC1h cm0ta2VybmVsQGxpc3RzLmluZnJhZGVhZC5vcmcKaHR0cDovL2xpc3RzLmluZnJhZGVhZC5vcmcv bWFpbG1hbi9saXN0aW5mby9saW51eC1hcm0ta2VybmVsCg==