From nobody Thu Apr 25 20:15:56 2024 Delivered-To: importer@patchew.org Received-SPF: none (zohomail.com: 192.237.175.120 is neither permitted nor denied by domain of lists.xenproject.org) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; spf=none (zohomail.com: 192.237.175.120 is neither permitted nor denied by domain of lists.xenproject.org) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org ARC-Seal: i=1; a=rsa-sha256; t=1574715535; cv=none; d=zohomail.com; s=zohoarc; b=ff/iDmeoKAvfTvYSkQck9hgQhh4/GDG1LxCKuHO3PD9XMCD5SpkKzOGz0ouogKu2ByWG1r0DHmYB5irU049uf+7VDDtiIyG/dzPj091xf3Uwfs+kC2ONUSrUIrLNk2948JlrWayQy5R3nRtu8ey92YJJ55Ckf/xudnpIzRz4E/o= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1574715535; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:Sender:Subject:To; bh=I62uovgEwz+9ayMoQe2CYFtY9Qx2YE2aWhu6iwruHnc=; b=YnTKelkYxRe8tZgBT+5eJ7OlCpt9m7eFTiHY7B5FVdcQi46UPveQBVA9WCJlzm5YTcT5SzP0ExQqEM//QbTcUzqWMuUEzQywizMy65r9zWCrBBuF7FvI/8QyGmZg3n6Nb8eR1q4+fSfcP5Is2m2AkyHDXZA6SjhmqMHwmdiEawI= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=none (zohomail.com: 192.237.175.120 is neither permitted nor denied by domain of lists.xenproject.org) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1574715534885201.04276159487176; Mon, 25 Nov 2019 12:58:54 -0800 (PST) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iZLQx-000337-81; Mon, 25 Nov 2019 20:58:11 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iZLQv-000332-Ok for xen-devel@lists.xenproject.org; Mon, 25 Nov 2019 20:58:09 +0000 Received: from webmail.dornerworks.com (unknown [12.207.209.150]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTP id 473ce87d-0fc6-11ea-a396-12813bfff9fa; Mon, 25 Nov 2019 20:58:08 +0000 (UTC) X-Inumbo-ID: 473ce87d-0fc6-11ea-a396-12813bfff9fa From: Jeff Kubascik To: Date: Mon, 25 Nov 2019 15:58:00 -0500 Message-ID: <20191125205800.64602-1-jeff.kubascik@dornerworks.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [172.27.13.171] X-ClientProxiedBy: Mcbain.dw.local (172.27.1.45) To Mcbain.dw.local (172.27.1.45) X-spam-status: No, score=-2.9 required=3.5 tests=ALL_TRUSTED, BAYES_00, MAILSHELL_SCORE_0_4 X-Spam-Flag: NO Subject: [Xen-devel] [PATCH v2] xen/arm: initialize vpl011 flag register X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Stewart Hildebrand , Volodymyr Babchuk , Stefano Stabellini , Julien Grall Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" The tx/rx fifo flags were not set when the vpl011 is initialized. This is a problem for certain guests that are operating in polled mode, as a guest will generally check the rx fifo empty flag to determine if there is data before doing a read. The result is a continuous spam of the message "vpl011: Unexpected IN ring buffer empty" before the first valid character is received. This initializes the flag status register to the default specified in the PL011 technical reference manual. Signed-off-by: Jeff Kubascik Changes in v2: - Moved uartfr initialization to later point in function after potential return/failure points Acked-by: Julien Grall --- xen/arch/arm/vpl011.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/xen/arch/arm/vpl011.c b/xen/arch/arm/vpl011.c index 7bc5eeb207..895f436cc4 100644 --- a/xen/arch/arm/vpl011.c +++ b/xen/arch/arm/vpl011.c @@ -668,6 +668,8 @@ int domain_vpl011_init(struct domain *d, struct vpl011_= init_info *info) goto out2; } =20 + vpl011->uartfr =3D TXFE | RXFE; + spin_lock_init(&vpl011->lock); =20 register_mmio_handler(d, &vpl011_mmio_handler, --=20 2.17.1 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel