From patchwork Wed Feb 16 06:59:11 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Linyu Yuan X-Patchwork-Id: 543287 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 04621C4332F for ; Wed, 16 Feb 2022 07:07:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229742AbiBPHH5 (ORCPT ); Wed, 16 Feb 2022 02:07:57 -0500 Received: from gmail-smtp-in.l.google.com ([23.128.96.19]:35020 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229557AbiBPHHy (ORCPT ); Wed, 16 Feb 2022 02:07:54 -0500 Received: from alexa-out.qualcomm.com (alexa-out.qualcomm.com [129.46.98.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 855B921FEFC for ; Tue, 15 Feb 2022 23:07:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; i=@quicinc.com; q=dns/txt; s=qcdkim; t=1644995222; x=1676531222; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=J2ELd7WDH9g6VZZPP7ORdYRCnvOlzmsM/EmctzFyFmY=; b=epuC7yZGlVOf56bpj+aL3klKBd1xCxEFNKvZVbEwZOxoV6ZF3DUIW133 ztI1xZMXvVUIwk9xOLvn6a2bFFH1wkqfAjoRlQvcuUXu3TK9ICQaod54L Xmd8tuQGmEndG7XQa0N+v4LqBF7ljDM6s05imQenpwlUNAmwmt+/5fEkU s=; Received: from ironmsg08-lv.qualcomm.com ([10.47.202.152]) by alexa-out.qualcomm.com with ESMTP; 15 Feb 2022 22:59:28 -0800 X-QCInternal: smtphost Received: from nasanex01c.na.qualcomm.com ([10.47.97.222]) by ironmsg08-lv.qualcomm.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Feb 2022 22:59:28 -0800 Received: from nalasex01b.na.qualcomm.com (10.47.209.197) by nasanex01c.na.qualcomm.com (10.47.97.222) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.15; Tue, 15 Feb 2022 22:59:27 -0800 Received: from linyyuan-gv.qualcomm.com (10.80.80.8) by nalasex01b.na.qualcomm.com (10.47.209.197) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.922.19; Tue, 15 Feb 2022 22:59:25 -0800 From: Linyu Yuan To: Mathias Nyman , Greg Kroah-Hartman CC: , Jack Pham , "Linyu Yuan" Subject: [PATCH 1/5] usb: host: xhci: use ffs() in xhci_mem_init() Date: Wed, 16 Feb 2022 14:59:11 +0800 Message-ID: <1644994755-12975-2-git-send-email-quic_linyyuan@quicinc.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1644994755-12975-1-git-send-email-quic_linyyuan@quicinc.com> References: <1644994755-12975-1-git-send-email-quic_linyyuan@quicinc.com> MIME-Version: 1.0 X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nalasex01b.na.qualcomm.com (10.47.209.197) Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org The for loop to find page size bit can be replaced with ffs(). Signed-off-by: Linyu Yuan --- drivers/usb/host/xhci-mem.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c index 0e31206..3cbc7f2 100644 --- a/drivers/usb/host/xhci-mem.c +++ b/drivers/usb/host/xhci-mem.c @@ -2395,12 +2395,7 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags) page_size = readl(&xhci->op_regs->page_size); xhci_dbg_trace(xhci, trace_xhci_dbg_init, "Supported page size register = 0x%x", page_size); - for (i = 0; i < 16; i++) { - if ((0x1 & page_size) != 0) - break; - page_size = page_size >> 1; - } - if (i < 16) + if ((i = ffs(page_size)) < 16) xhci_dbg_trace(xhci, trace_xhci_dbg_init, "Supported page size of %iK", (1 << (i+12)) / 1024); else