From nobody Tue Apr 30 20:45:10 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1512926983097189.52367746868651; Sun, 10 Dec 2017 09:29:43 -0800 (PST) Received: from localhost ([::1]:45406 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eO5Q1-0000Nf-2C for importer@patchew.org; Sun, 10 Dec 2017 12:29:37 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60028) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eO5OL-0007Is-L5 for qemu-devel@nongnu.org; Sun, 10 Dec 2017 12:27:55 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eO5OI-0000kq-Dp for qemu-devel@nongnu.org; Sun, 10 Dec 2017 12:27:53 -0500 Received: from iserv.reactos.org ([2a01:4f8:221:4c5::3]:57511) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1eO5OI-0000iL-3s for qemu-devel@nongnu.org; Sun, 10 Dec 2017 12:27:50 -0500 Received: from rob92-5-82-227-227-196.fbx.proxad.net ([82.227.227.196] helo=localhost.localdomain) by iserv.reactos.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.84_2) (envelope-from ) id 1eO5OE-0003Jm-AA; Sun, 10 Dec 2017 17:27:46 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=reactos.org; s=25047; h=Content-Transfer-Encoding:Content-Type:MIME-Version:Message-Id:Date:Subject:Cc:To:From; bh=y1TDRtSDXgv6pCQm8j95zJaogQ9kOHDrOuux16pn908=; b=Tf08rULhD3T6jG6gKBr904piuQqcoM4pvfaR8mVWPjzTjw2NnX2MGpIpkzzes8Kh5a6EEtMOABNkwbzat6CoNe37pynOho+WTOmWU0xMtFreZRhcPqlYVfeIh7cPTzvWviadka8/tqRm6M0ky+Db3nYcsvw9XV7gombvqJjKmpY=; From: =?UTF-8?q?Herv=C3=A9=20Poussineau?= To: qemu-devel@nongnu.org Date: Sun, 10 Dec 2017 18:27:03 +0100 Message-Id: <20171210172703.27866-1-hpoussin@reactos.org> X-Mailer: git-send-email 2.11.0 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2a01:4f8:221:4c5::3 Subject: [Qemu-devel] [PATCH] smbus: do not immediately complete commands X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Paolo Bonzini , =?UTF-8?q?Herv=C3=A9=20Poussineau?= , "Michael S. Tsirkin" Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) X-ZohoMail: RDKM_2 RSF_0 Z_629925259 SPT_0 PIIX4 errata says that "immediate polling of the Host Status Register BUSY bit may indicate that the SMBus is NOT busy." Due to this, some code does the following steps: (a) set parameters (b) start command (c) check for smbus busy bit set (to know that command started) (d) check for smbus busy bit not set (to know that command finished) Let (c) happen, by immediately setting the busy bit, and really executing the command when status register has been read once. This fixes a problem with AMIBIOS, which can now properly initialize the PI= IX4. Signed-off-by: Herv=C3=A9 Poussineau --- hw/i2c/pm_smbus.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/hw/i2c/pm_smbus.c b/hw/i2c/pm_smbus.c index 6fc3923f56..ec060d58cc 100644 --- a/hw/i2c/pm_smbus.c +++ b/hw/i2c/pm_smbus.c @@ -63,6 +63,9 @@ static void smb_transaction(PMSMBus *s) I2CBus *bus =3D s->smbus; int ret; =20 + assert(s->smb_stat & STS_HOST_BUSY); + s->smb_stat &=3D ~STS_HOST_BUSY; + SMBUS_DPRINTF("SMBus trans addr=3D0x%02x prot=3D0x%02x\n", addr, prot); /* Transaction isn't exec if STS_DEV_ERR bit set */ if ((s->smb_stat & STS_DEV_ERR) !=3D 0) { @@ -135,6 +138,13 @@ error: =20 } =20 +static void smb_transaction_start(PMSMBus *s) +{ + /* Do not execute immediately the command ; it will be + * executed when guest will read SMB_STAT register */ + s->smb_stat |=3D STS_HOST_BUSY; +} + static void smb_ioport_writeb(void *opaque, hwaddr addr, uint64_t val, unsigned width) { @@ -150,7 +160,7 @@ static void smb_ioport_writeb(void *opaque, hwaddr addr= , uint64_t val, case SMBHSTCNT: s->smb_ctl =3D val; if (val & 0x40) - smb_transaction(s); + smb_transaction_start(s); break; case SMBHSTCMD: s->smb_cmd =3D val; @@ -182,6 +192,10 @@ static uint64_t smb_ioport_readb(void *opaque, hwaddr = addr, unsigned width) switch(addr) { case SMBHSTSTS: val =3D s->smb_stat; + if (s->smb_stat & STS_HOST_BUSY) { + /* execute command now */ + smb_transaction(s); + } break; case SMBHSTCNT: s->smb_index =3D 0; --=20 2.11.0