From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933261Ab3BSRtQ (ORCPT ); Tue, 19 Feb 2013 12:49:16 -0500 Received: from na01-by1-obe.ptr.o365filtering.com ([64.4.22.90]:30855 "EHLO na01-by1-obe.outbound.o365filtering.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933041Ab3BSRtN (ORCPT ); Tue, 19 Feb 2013 12:49:13 -0500 From: Haiyang Zhang To: Olaf Hering CC: "FlorianSchandinat@gmx.de" , "linux-fbdev@vger.kernel.org" , KY Srinivasan , "jasowang@redhat.com" , "linux-kernel@vger.kernel.org" , "devel@linuxdriverproject.org" Subject: RE: [PATCH RFC] video: Add Hyper-V Synthetic Video Frame Buffer Driver Thread-Topic: [PATCH RFC] video: Add Hyper-V Synthetic Video Frame Buffer Driver Thread-Index: AQHOC6xQKsSDc1Q1WkuxN29CXfjd55iB8XAA//+EDqA= Date: Tue, 19 Feb 2013 17:48:39 +0000 Message-ID: <1ca36b5d55c64ac6b8854c4f216ef8e5@DFM-TK5MBX15-06.exchange.corp.microsoft.com> References: <1360955396-14183-1-git-send-email-haiyangz@microsoft.com> <20130219165118.GA17715@aepfle.de> In-Reply-To: <20130219165118.GA17715@aepfle.de> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [157.54.51.13] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 X-Forefront-Antispam-Report: CIP:131.107.1.17;CTRY:US;IPV:NLI;EFV:NLI;SFV:NSPM;SFS:(51704002)(13464002)(377454001)(24454001)(164054002)(189002)(199002)(56816002)(4396001)(50466001)(31966008)(23676001)(79102001)(16406001)(50986001)(5343655001)(44976002)(74662001)(77982001)(59766001)(51856001)(74502001)(47446002)(56776001)(65816001)(76482001)(47976001)(47736001)(49866001)(876001)(54356001)(54316002)(63696002)(47776003)(33646001)(20776003)(66066001)(80022001)(53806001)(46102001)(24736002);DIR:OUT;SFP:;SCL:1;SRVR:BY2SR01MB609;H:hybrid.exchange.microsoft.com;RD:mail1.exchange.microsoft.com;MX:1;A:1;LANG:en; X-Forefront-PRVS: 0762FFD075 X-OriginatorOrg: DuplicateDomain-7923a859-03c9-4312-a77c-440aa45aaf52.microsoft.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id r1JHnGtn031072 > -----Original Message----- > From: Olaf Hering [mailto:olaf@aepfle.de] > Sent: Tuesday, February 19, 2013 11:51 AM > To: Haiyang Zhang > Cc: FlorianSchandinat@gmx.de; linux-fbdev@vger.kernel.org; KY Srinivasan; > jasowang@redhat.com; linux-kernel@vger.kernel.org; > devel@linuxdriverproject.org > Subject: Re: [PATCH RFC] video: Add Hyper-V Synthetic Video Frame Buffer > Driver > > On Fri, Feb 15, Haiyang Zhang wrote: > > > @@ -508,6 +544,18 @@ static int __init vesafb_init(void) > > int ret; > > char *option = NULL; > > > > +#if IS_ENABLED(CONFIG_HYPERV_FB) > > + /* > > + * On Hyper-V both the emulated and synthetic video devices are > > + * available. To avoid conflicts, we disable vesafb for the > emulated > > + * video if hyperv_fb is configured. > > + */ > > + if (is_hyperv()) { > > + pr_info("Disabled vesafb on Hyper-V.\n"); > > + return -ENODEV; > > + } > > +#endif > > What is the reason for this hook? Is it not possible to claim the > display like its appearently done by other drivers (like radeonfb can > take over display from vesafb)? The emulated video device is a separate device from the synthetic video. The synthetic driver can only take control of the synthetic video, but not the emulated video. Actually, we already have a similar mechanism in ata/ata_piix.c to disable emulated IDE drive on Hyper-V, so it won't conflict with the synthetic drive. Thanks, - Haiyang {.n++%ݶw{.n+{G{ayʇڙ,jfhz_(階ݢj"mG?&~iOzv^m ?I