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=-10.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 3E36FC433DF for ; Mon, 17 Aug 2020 13:49:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 19B0A2075B for ; Mon, 17 Aug 2020 13:49:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597672196; bh=neILveBskNIGri0vUIbvh+uU43bAIKbA+3Ui69RMDEs=; h=From:To:Cc:Subject:In-Reply-To:References:Date:List-ID:From; b=npYvEAZzMkd32sNYXYWPdNCC/Hdpcy3DUHLl1k1eMP0uyF5XvKFnL4RxRdK4sg1MH 5j1oq+9CUkkwBYwH6RL7rdS072fzrrGfE3XnuV2gWvhmAO8LKJw78QtP8BEYQwyAjS YHRsUrRW1QaAaTZpnjGI4OnKo/Fmh1ovF6QDyE00= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728698AbgHQNto (ORCPT ); Mon, 17 Aug 2020 09:49:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:53292 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727953AbgHQNtm (ORCPT ); Mon, 17 Aug 2020 09:49:42 -0400 Received: from saruman (unknown [194.34.132.59]) (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 383D72065C; Mon, 17 Aug 2020 13:49:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597672181; bh=neILveBskNIGri0vUIbvh+uU43bAIKbA+3Ui69RMDEs=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=B2dQcjMvHdPr+yGQWxV5pReE59glr540FiC9zAx/WQDn0xn+sIBKD+xL2t18N9sM4 SAWDG5mRanAZS3YXc1SbcOWFN+I++rs+P2t0AF94BeFQC9kUnY534zUyGQ1LVc4sEc Ew7LVl8v3JitXfdLzjWSBWhzkaD1SkxqAUpbWWOg= From: Felipe Balbi To: rentao.bupt@gmail.com, Greg Kroah-Hartman , Joel Stanley , Andrew Jeffery , Benjamin Herrenschmidt , Chunfeng Yun , Stephen Boyd , linux-usb@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org, openbmc@lists.ozlabs.org, taoren@fb.com Cc: Tao Ren Subject: Re: [PATCH] usb: gadget: aspeed: fixup vhub port irq handling In-Reply-To: <20200528011154.30355-1-rentao.bupt@gmail.com> References: <20200528011154.30355-1-rentao.bupt@gmail.com> Date: Mon, 17 Aug 2020 16:49:32 +0300 Message-ID: <875z9hz8k3.fsf@kernel.org> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Hi, rentao.bupt@gmail.com writes: > From: Tao Ren > > This is a follow-on patch for commit a23be4ed8f48 ("usb: gadget: aspeed: > improve vhub port irq handling"): for_each_set_bit() is replaced with > simple for() loop because for() loop runs faster on ASPEED BMC. > > Signed-off-by: Tao Ren > --- > drivers/usb/gadget/udc/aspeed-vhub/core.c | 10 +++------- > drivers/usb/gadget/udc/aspeed-vhub/vhub.h | 3 +++ > 2 files changed, 6 insertions(+), 7 deletions(-) > > diff --git a/drivers/usb/gadget/udc/aspeed-vhub/core.c b/drivers/usb/gadg= et/udc/aspeed-vhub/core.c > index cdf96911e4b1..be7bb64e3594 100644 > --- a/drivers/usb/gadget/udc/aspeed-vhub/core.c > +++ b/drivers/usb/gadget/udc/aspeed-vhub/core.c > @@ -135,13 +135,9 @@ static irqreturn_t ast_vhub_irq(int irq, void *data) >=20=20 > /* Handle device interrupts */ > if (istat & vhub->port_irq_mask) { > - unsigned long bitmap =3D istat; > - int offset =3D VHUB_IRQ_DEV1_BIT; > - int size =3D VHUB_IRQ_DEV1_BIT + vhub->max_ports; > - > - for_each_set_bit_from(offset, &bitmap, size) { > - i =3D offset - VHUB_IRQ_DEV1_BIT; > - ast_vhub_dev_irq(&vhub->ports[i].dev); > + for (i =3D 0; i < vhub->max_ports; i++) { > + if (istat & VHUB_DEV_IRQ(i)) > + ast_vhub_dev_irq(&vhub->ports[i].dev); how have you measured your statement above? for_each_set_bit() does exactly what you did. Unless your architecture has an instruction which helps finds the next set bit (like cls on ARM), which, then, makes it much faster. =2D-=20 balbi --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQJFBAEBCAAvFiEElLzh7wn96CXwjh2IzL64meEamQYFAl86iuwRHGJhbGJpQGtl cm5lbC5vcmcACgkQzL64meEamQZuXg//doj2VlNrrpXSD2a83iUegA+NRRRKef1U PRfUUrIK4igGr/FiQAhE9Mlilxj/sZTLcQ6qe1EhIY+f5JhyfucZ5Te4WhNFaxtZ UJp24ndXVc0q8NTmSkre+c6GLX/lD4NFlfgMSsdqpvAlYJirzL4GY63EWA9W8I3k cO4Igdvi8ZskhUgX2QBCM4kDxMk+WxV6PrD8L4EykHmXTzFqVJxKM30BO7U0Gdd4 bmImEVCqzUDSivYKC7xwDWnT0HAXjbm38tcb4hq40pePVtDNEGFiNd3NUo953SvP 065liQg/4ats64P21c+PN0qXFovkWoSTJBa1yzcqfWF+Yi8fKI5UVNp49W0CJZ2m lEKNc/H4+qzEysoXCgWCCznDg4RCxE0f4Y5OsNxkf63QvVEAaFRePgNZ6txble7v dJueHYNiEfsgCe2QUCxl4f805gq2+iIMKGnWvEdwcdlpUCmop+CBXouD9MuMt+hB OLDU6hSo/REsEHKVsooiICwfUOuD0xrqiqObcLKwSd0krXnDRkkYjYm4FvN4u43y y+sTwkU5jswAvcBCHDgayGgm37U0QsDLpZW5voCirwaPqdC+09yVQ18/lx4cA+Lq Y2WHyvRRssi5U8G3YHQUoLVJ7umEx5o6k13rBQNBnueyfEsVM3G8V74j+uuYLGzO BbmxKI2a0bY= =TM9v -----END PGP SIGNATURE----- --=-=-=--