From patchwork Thu Jun 20 19:46:06 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: BALATON Zoltan X-Patchwork-Id: 1119774 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=eik.bme.hu Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 45VCyD5Q7nz9s5c for ; Fri, 21 Jun 2019 06:26:12 +1000 (AEST) Received: from localhost ([::1]:52748 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1he3dI-0004iK-JM for incoming@patchwork.ozlabs.org; Thu, 20 Jun 2019 16:26:08 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:45647) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1he36c-0007Lh-8V for qemu-devel@nongnu.org; Thu, 20 Jun 2019 15:52:23 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1he36b-0004jc-2a for qemu-devel@nongnu.org; Thu, 20 Jun 2019 15:52:22 -0400 Received: from zero.eik.bme.hu ([2001:738:2001:2001::2001]:24544) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1he36a-0004e9-On for qemu-devel@nongnu.org; Thu, 20 Jun 2019 15:52:20 -0400 Received: from zero.eik.bme.hu (blah.eik.bme.hu [152.66.115.182]) by localhost (Postfix) with SMTP id E510D7462AA; Thu, 20 Jun 2019 21:52:13 +0200 (CEST) Received: by zero.eik.bme.hu (Postfix, from userid 432) id C54127461AE; Thu, 20 Jun 2019 21:52:13 +0200 (CEST) From: BALATON Zoltan Date: Thu, 20 Jun 2019 21:46:06 +0200 To: qemu-devel@nongnu.org Message-Id: <20190620195213.C54127461AE@zero.eik.bme.hu> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2001:738:2001:2001::2001 Subject: [Qemu-devel] [PATCH] ati-vga: Clarify comment (to be squashed in previous patch) X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Gerd Hoffmann Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Signed-off-by: BALATON Zoltan --- hw/display/ati.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/hw/display/ati.c b/hw/display/ati.c index 6fbdda288f..932a1eacea 100644 --- a/hw/display/ati.c +++ b/hw/display/ati.c @@ -538,9 +538,14 @@ static void ati_mm_write(void *opaque, hwaddr addr, case GPIO_MONID ... GPIO_MONID + 3: /* FIXME What does Radeon have here? */ if (s->dev_id == PCI_DEVICE_ID_ATI_RAGE128_PF) { - /* Rage128p accesses DDC used to get EDID on these pins */ ati_reg_write_offs(&s->regs.gpio_monid, addr - GPIO_MONID, data, size); + /* + * Rage128p accesses DDC used to get EDID via these bits. + * Only touch i2c when write overlaps 3rd byte because some + * drivers access this reg via multiple partial writes and + * without this spurious bits would be sent. + */ if ((s->regs.gpio_monid & BIT(25)) && addr <= GPIO_MONID + 2 && addr + size > GPIO_MONID + 2) { s->regs.gpio_monid = ati_i2c(s->bbi2c, s->regs.gpio_monid, 1);