From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754336AbcK1Huy convert rfc822-to-8bit (ORCPT ); Mon, 28 Nov 2016 02:50:54 -0500 Received: from mx1.redhat.com ([209.132.183.28]:59794 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751725AbcK1Hur (ORCPT ); Mon, 28 Nov 2016 02:50:47 -0500 Message-ID: <1480319444.20061.4.camel@redhat.com> Subject: Re: virtio gpu sparse warning From: Gerd Hoffmann To: "Michael S. Tsirkin" Cc: Jiri Slaby , virtualization@lists.linux-foundation.org, Linux kernel mailing list , David Airlie , dri-devel@lists.freedesktop.org Date: Mon, 28 Nov 2016 08:50:44 +0100 In-Reply-To: <20161124045101-mutt-send-email-mst@kernel.org> References: <20161108223153-mutt-send-email-mst@kernel.org> <1478678517.2078.12.camel@redhat.com> <1479301975.25611.23.camel@redhat.com> <20161124045101-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Mime-Version: 1.0 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Mon, 28 Nov 2016 07:50:46 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Do, 2016-11-24 at 04:57 +0200, Michael S. Tsirkin wrote: > sparse produces these warnings: > > drivers/gpu/drm/virtio/virtgpu_fb.c:340:27: warning: incorrect type in > assignment (different address spaces) > drivers/gpu/drm/virtio/virtgpu_fb.c:340:27: expected char [noderef] > *screen_base > drivers/gpu/drm/virtio/virtgpu_fb.c:340:27: got void *vmap > > This is because the expected type is void __iomem *, while > virtio gpu object is void *vmap. > > We could just cast the warning away but I'm not sure this > is not a symptom of an actual problem. For example, might > some code call iounmap on this address? Nobody is ever going to unmap that, the kernel will simply use given address to access the framebuffer. Actually it looks like this (in include/linux/fb.h): union { char __iomem *screen_base; /* Virtual address */ char *screen_buffer; }; and given that the virtio always uses normal ram as backing storage for the framebuffer we should simply s/screen_base/screen_buffer/. I'll go prepare a patch. cheers, Gerd From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gerd Hoffmann Subject: Re: virtio gpu sparse warning Date: Mon, 28 Nov 2016 08:50:44 +0100 Message-ID: <1480319444.20061.4.camel@redhat.com> References: <20161108223153-mutt-send-email-mst@kernel.org> <1478678517.2078.12.camel@redhat.com> <1479301975.25611.23.camel@redhat.com> <20161124045101-mutt-send-email-mst@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by gabe.freedesktop.org (Postfix) with ESMTPS id 11F0C6E1B8 for ; Mon, 28 Nov 2016 07:50:47 +0000 (UTC) In-Reply-To: <20161124045101-mutt-send-email-mst@kernel.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: "Michael S. Tsirkin" Cc: Jiri Slaby , Linux kernel mailing list , dri-devel@lists.freedesktop.org, virtualization@lists.linux-foundation.org List-Id: dri-devel@lists.freedesktop.org T24gRG8sIDIwMTYtMTEtMjQgYXQgMDQ6NTcgKzAyMDAsIE1pY2hhZWwgUy4gVHNpcmtpbiB3cm90 ZToKPiBzcGFyc2UgcHJvZHVjZXMgdGhlc2Ugd2FybmluZ3M6Cj4gCj4gZHJpdmVycy9ncHUvZHJt L3ZpcnRpby92aXJ0Z3B1X2ZiLmM6MzQwOjI3OiB3YXJuaW5nOiBpbmNvcnJlY3QgdHlwZSBpbgo+ IGFzc2lnbm1lbnQgKGRpZmZlcmVudCBhZGRyZXNzIHNwYWNlcykKPiBkcml2ZXJzL2dwdS9kcm0v dmlydGlvL3ZpcnRncHVfZmIuYzozNDA6Mjc6ICAgIGV4cGVjdGVkIGNoYXIgW25vZGVyZWZdCj4g PGFzbjoyPipzY3JlZW5fYmFzZQo+IGRyaXZlcnMvZ3B1L2RybS92aXJ0aW8vdmlydGdwdV9mYi5j OjM0MDoyNzogICAgZ290IHZvaWQgKnZtYXAKPiAKPiBUaGlzIGlzIGJlY2F1c2UgdGhlIGV4cGVj dGVkIHR5cGUgaXMgdm9pZCBfX2lvbWVtICosIHdoaWxlCj4gdmlydGlvIGdwdSBvYmplY3QgaXMg dm9pZCAqdm1hcC4KPiAKPiBXZSBjb3VsZCBqdXN0IGNhc3QgdGhlIHdhcm5pbmcgYXdheSBidXQg SSdtIG5vdCBzdXJlIHRoaXMKPiBpcyBub3QgYSBzeW1wdG9tIG9mIGFuIGFjdHVhbCBwcm9ibGVt LiBGb3IgZXhhbXBsZSwgbWlnaHQKPiBzb21lIGNvZGUgY2FsbCBpb3VubWFwIG9uIHRoaXMgYWRk cmVzcz8KCk5vYm9keSBpcyBldmVyIGdvaW5nIHRvIHVubWFwIHRoYXQsIHRoZSBrZXJuZWwgd2ls bCBzaW1wbHkgdXNlIGdpdmVuCmFkZHJlc3MgdG8gYWNjZXNzIHRoZSBmcmFtZWJ1ZmZlci4KCkFj dHVhbGx5IGl0IGxvb2tzIGxpa2UgdGhpcyAoaW4gaW5jbHVkZS9saW51eC9mYi5oKToKCiAgICAg ICAgdW5pb24gewogICAgICAgICAgICAgICAgY2hhciBfX2lvbWVtICpzY3JlZW5fYmFzZTsgICAg ICAvKiBWaXJ0dWFsIGFkZHJlc3MgKi8KICAgICAgICAgICAgICAgIGNoYXIgKnNjcmVlbl9idWZm ZXI7CiAgICAgICAgfTsKCmFuZCBnaXZlbiB0aGF0IHRoZSB2aXJ0aW8gYWx3YXlzIHVzZXMgbm9y bWFsIHJhbSBhcyBiYWNraW5nIHN0b3JhZ2UgZm9yCnRoZSBmcmFtZWJ1ZmZlciB3ZSBzaG91bGQg c2ltcGx5IHMvc2NyZWVuX2Jhc2Uvc2NyZWVuX2J1ZmZlci8uICBJJ2xsIGdvCnByZXBhcmUgYSBw YXRjaC4KCmNoZWVycywKICBHZXJkCgpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fXwpkcmktZGV2ZWwgbWFpbGluZyBsaXN0CmRyaS1kZXZlbEBsaXN0cy5mcmVl ZGVza3RvcC5vcmcKaHR0cHM6Ly9saXN0cy5mcmVlZGVza3RvcC5vcmcvbWFpbG1hbi9saXN0aW5m by9kcmktZGV2ZWwK