From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1947068AbdD1KCy convert rfc822-to-8bit (ORCPT ); Fri, 28 Apr 2017 06:02:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38472 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1424569AbdD1KCq (ORCPT ); Fri, 28 Apr 2017 06:02:46 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 0F8FD65D01 Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=kraxel@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 0F8FD65D01 Message-ID: <1493373758.23357.27.camel@redhat.com> Subject: Re: [PATCH 3/6] drm: fourcc byteorder: add bigendian support to drm_mode_legacy_fb_format From: Gerd Hoffmann To: Michel =?ISO-8859-1?Q?D=E4nzer?= Cc: Daniel Vetter , amd-gfx@lists.freedesktop.org, open list , dri-devel@lists.freedesktop.org Date: Fri, 28 Apr 2017 12:02:38 +0200 In-Reply-To: <668bc373-1614-a095-6085-15c040f322b8@daenzer.net> References: <20170424062532.26722-1-kraxel@redhat.com> <20170424062532.26722-4-kraxel@redhat.com> <3b872a56-80b5-0c44-712f-a9517489eb24@daenzer.net> <1493185990.23739.7.camel@redhat.com> <8f91cc58-16dc-5899-66b6-06d430a18801@daenzer.net> <1493208671.23739.19.camel@redhat.com> <6bd62182-0de5-a8a7-78c3-029fc73ecc91@daenzer.net> <1493275550.31995.31.camel@redhat.com> <668bc373-1614-a095-6085-15c040f322b8@daenzer.net> 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 [10.5.110.38]); Fri, 28 Apr 2017 10:02:41 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, > > So just not using the swapping indeed looks like the only sensible > > option. Which in turn implies there is no BGRA8888 support for dumb > > bos. Hmm, I can see the problem. Userspace expectation appears to be > > that ADDFB configures a native endian framebuffer, which the driver > > simply can't do on bigendian. > > ... with pre-R600 GPUs. Sure. > > So, what can/should the driver do here? Throw errors for ADDFB and > > force userspace to use ADDFB2? From a design point of view the best > > option, but in the other hand I suspect that could break the xorg radeon > > driver ... > > Yes, it would. > One thing we could do is provide a way for userspace to query the > effective format(s) as seen by the GPU and/or CPU. We already have almost no testing on bigendian. I doubt adding generic interfaces specifically to handle this case is going to work because most userspace will simply not implement that correctly (or at all). Having support for this in the radeon ioctls might work, because only radeon kernel + xorg driver have to get things right then. But I suspect we already have that. You've mentioned elsewhere in the thread that the xorg driver doesn't turn on byteswapping, so the ability to configure that seems to be somewhere in the API ... > It might also make sense for the radeon driver to set the > RADEON_TILING_SWAP_{16,32}BIT flags for dumb BOs. That could work. But I guess someone with test hardware needs to try, to make sure we don't miss corner cases here. cheers, Gerd From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gerd Hoffmann Subject: Re: [PATCH 3/6] drm: fourcc byteorder: add bigendian support to drm_mode_legacy_fb_format Date: Fri, 28 Apr 2017 12:02:38 +0200 Message-ID: <1493373758.23357.27.camel@redhat.com> References: <20170424062532.26722-1-kraxel@redhat.com> <20170424062532.26722-4-kraxel@redhat.com> <3b872a56-80b5-0c44-712f-a9517489eb24@daenzer.net> <1493185990.23739.7.camel@redhat.com> <8f91cc58-16dc-5899-66b6-06d430a18801@daenzer.net> <1493208671.23739.19.camel@redhat.com> <6bd62182-0de5-a8a7-78c3-029fc73ecc91@daenzer.net> <1493275550.31995.31.camel@redhat.com> <668bc373-1614-a095-6085-15c040f322b8@daenzer.net> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <668bc373-1614-a095-6085-15c040f322b8-otUistvHUpPR7s880joybQ@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: amd-gfx-bounces-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org Sender: "amd-gfx" To: Michel =?ISO-8859-1?Q?D=E4nzer?= Cc: Daniel Vetter , dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, open list , amd-gfx-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org List-Id: dri-devel@lists.freedesktop.org ICBIaSwKCj4gPiBTbyBqdXN0IG5vdCB1c2luZyB0aGUgc3dhcHBpbmcgaW5kZWVkIGxvb2tzIGxp a2UgdGhlIG9ubHkgc2Vuc2libGUKPiA+IG9wdGlvbi4gIFdoaWNoIGluIHR1cm4gaW1wbGllcyB0 aGVyZSBpcyBubyBCR1JBODg4OCBzdXBwb3J0IGZvciBkdW1iCj4gPiBib3MuICBIbW0sIEkgY2Fu IHNlZSB0aGUgcHJvYmxlbS4gIFVzZXJzcGFjZSBleHBlY3RhdGlvbiBhcHBlYXJzIHRvIGJlCj4g PiB0aGF0IEFEREZCIGNvbmZpZ3VyZXMgYSBuYXRpdmUgZW5kaWFuIGZyYW1lYnVmZmVyLCB3aGlj aCB0aGUgZHJpdmVyCj4gPiBzaW1wbHkgY2FuJ3QgZG8gb24gYmlnZW5kaWFuLgo+IAo+IC4uLiB3 aXRoIHByZS1SNjAwIEdQVXMuCgpTdXJlLgoKPiA+IFNvLCB3aGF0IGNhbi9zaG91bGQgdGhlIGRy aXZlciBkbyBoZXJlPyAgVGhyb3cgZXJyb3JzIGZvciBBRERGQiBhbmQKPiA+IGZvcmNlIHVzZXJz cGFjZSB0byB1c2UgQURERkIyPyAgRnJvbSBhIGRlc2lnbiBwb2ludCBvZiB2aWV3IHRoZSBiZXN0 Cj4gPiBvcHRpb24sIGJ1dCBpbiB0aGUgb3RoZXIgaGFuZCBJIHN1c3BlY3QgdGhhdCBjb3VsZCBi cmVhayB0aGUgeG9yZyByYWRlb24KPiA+IGRyaXZlciAuLi4KPiAKPiBZZXMsIGl0IHdvdWxkLgoK PiBPbmUgdGhpbmcgd2UgY291bGQgZG8gaXMgcHJvdmlkZSBhIHdheSBmb3IgdXNlcnNwYWNlIHRv IHF1ZXJ5IHRoZQo+IGVmZmVjdGl2ZSBmb3JtYXQocykgYXMgc2VlbiBieSB0aGUgR1BVIGFuZC9v ciBDUFUuCgpXZSBhbHJlYWR5IGhhdmUgYWxtb3N0IG5vIHRlc3Rpbmcgb24gYmlnZW5kaWFuLiAg SSBkb3VidCBhZGRpbmcgZ2VuZXJpYwppbnRlcmZhY2VzIHNwZWNpZmljYWxseSB0byBoYW5kbGUg dGhpcyBjYXNlIGlzIGdvaW5nIHRvIHdvcmsgYmVjYXVzZQptb3N0IHVzZXJzcGFjZSB3aWxsIHNp bXBseSBub3QgaW1wbGVtZW50IHRoYXQgY29ycmVjdGx5IChvciBhdCBhbGwpLgoKSGF2aW5nIHN1 cHBvcnQgZm9yIHRoaXMgaW4gdGhlIHJhZGVvbiBpb2N0bHMgbWlnaHQgd29yaywgYmVjYXVzZSBv bmx5CnJhZGVvbiBrZXJuZWwgKyB4b3JnIGRyaXZlciBoYXZlIHRvIGdldCB0aGluZ3MgcmlnaHQg dGhlbi4gIEJ1dCBJCnN1c3BlY3Qgd2UgYWxyZWFkeSBoYXZlIHRoYXQuICBZb3UndmUgbWVudGlv bmVkIGVsc2V3aGVyZSBpbiB0aGUgdGhyZWFkCnRoYXQgdGhlIHhvcmcgZHJpdmVyIGRvZXNuJ3Qg dHVybiBvbiBieXRlc3dhcHBpbmcsIHNvIHRoZSBhYmlsaXR5IHRvCmNvbmZpZ3VyZSB0aGF0IHNl ZW1zIHRvIGJlIHNvbWV3aGVyZSBpbiB0aGUgQVBJIC4uLgoKPiBJdCBtaWdodCBhbHNvIG1ha2Ug c2Vuc2UgZm9yIHRoZSByYWRlb24gZHJpdmVyIHRvIHNldCB0aGUKPiBSQURFT05fVElMSU5HX1NX QVBfezE2LDMyfUJJVCBmbGFncyBmb3IgZHVtYiBCT3MuCgpUaGF0IGNvdWxkIHdvcmsuICBCdXQg SSBndWVzcyBzb21lb25lIHdpdGggdGVzdCBoYXJkd2FyZSBuZWVkcyB0byB0cnksCnRvIG1ha2Ug c3VyZSB3ZSBkb24ndCBtaXNzIGNvcm5lciBjYXNlcyBoZXJlLgoKY2hlZXJzLAogIEdlcmQKCl9f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fCmFtZC1nZnggbWFp bGluZyBsaXN0CmFtZC1nZnhAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCmh0dHBzOi8vbGlzdHMuZnJl ZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vYW1kLWdmeAo=