From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gerd Hoffmann Subject: Re: [PATCH] drm: fourcc byteorder: brings header file comments in line with reality. Date: Fri, 21 Apr 2017 11:50:18 +0200 Message-ID: <1492768218.25675.33.camel@redhat.com> References: <20170421075825.6307-1-kraxel@redhat.com> <20170421092530.GE30290@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <20170421092530.GE30290@intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Ville =?ISO-8859-1?Q?Syrj=E4l=E4?= Cc: Michel =?ISO-8859-1?Q?D=E4nzer?= , open list , dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org, Daniel Vetter List-Id: amd-gfx.lists.freedesktop.org T24gRnIsIDIwMTctMDQtMjEgYXQgMTI6MjUgKzAzMDAsIFZpbGxlIFN5cmrDpGzDpCB3cm90ZToK PiBPbiBGcmksIEFwciAyMSwgMjAxNyBhdCAwOTo1ODoyNEFNICswMjAwLCBHZXJkIEhvZmZtYW5u IHdyb3RlOgo+ID4gV2hpbGUgd29ya2luZyBvbiBncmFwaGljcyBzdXBwb3J0IGZvciB2aXJ0dWFs IG1hY2hpbmVzIG9uIHBwYzY0ICh3aGljaAo+ID4gZXhpc3RzIGluIGJvdGggbGl0dGxlIGFuZCBi aWcgZW5kaWFuIHZhcmlhbnRzKSBJJ3ZlIGZpZ3VyZWQgdGhlIGNvbW1lbnRzCj4gPiBmb3IgdmFy aW91cyBkcm0gZm91cmNjIGZvcm1hdHMgaW4gdGhlIGhlYWRlciBmaWxlIGRvbid0IG1hdGNoIHJl YWxpdHkuCj4gPiAKPiA+IENvbW1lbnRzIHNheXMgdGhlIFJHQiBmb3JtYXRzIGFyZSBsaXR0bGUg ZW5kaWFuLCBidXQgaW4gcHJhY3RpY2UgdGhleQo+ID4gYXJlIG5hdGl2ZSBlbmRpYW4uICBMb29r IGF0IHRoZSBkcm1fbW9kZV9sZWdhY3lfZmJfZm9ybWF0KCkgaGVscGVyLiAgSXQKPiA+IG1hcHMg LS0gZm9yIGV4YW1wbGUgLS0gYnBwL2RlcHRoIDMyLzI0IHRvIERSTV9GT1JNQVRfWFJHQjg4ODgs IG5vIG1hdHRlcgo+ID4gd2hlbmV2ZXIgdGhlIG1hY2hpbmUgaXMgbGl0dGxlIGVuZGlhbiBvciBi aWcgZW5kaWFuLiAgVGhlIHVzZXJzIG9mIHRoaXMKPiA+IGZ1bmN0aW9uIChmYmRldiBlbXVsYXRp b24sIERSTV9JT0NUTF9NT0RFX0FEREZCKSBleHBlY3QgdGhlIGZyYW1lYnVmZmVyCj4gPiBpcyBu YXRpdmUgZW5kaWFuLCBub3QgbGl0dGxlIGVuZGlhbi4gIE1vc3QgdXNlcnNwYWNlIGFsc28gb3Bl cmF0ZXMgb24KPiA+IG5hdGl2ZSBlbmRpYW4gb25seS4KPiAKPiBJJ20gbm90IGEgZmFuIG9mICJu YXRpdmUiLiBOYXRpdmUgdG8gd2hhdD8gIkNQVSIgb3IgImhvc3QiIGlzIHdoYXQgSSdkCj4gY2Fs bCBpdC4KCm5hdGl2ZSA9PSB3aGF0ZXZlciB0aGUgY3B1IGlzIHVzaW5nLgoKSSBwZXJzb25hbGx5 IGZpbmQgIm5hdGl2ZSIgbW9yZSBpbnR1aXRpdmUsIGJ1dCBhdCB0aGUgZW5kIG9mIHRoZSBkYXkg SQpkb24ndCBtaW5kIG11Y2guICBJZiBwZW9wbGUgcHJlZmVyICJob3N0IiBvdmVyICJuYXRpdmUi IEknbGwgY2hhbmdlIGl0LgoKPiBBbmQgd2hhdCBhYm91dCB0aGUgbXhpZWQgZW5kaWFuIGNhc2U/ IEFyZSB5b3UganVzdCBnb2luZyB0byBwcmV0ZW5kIGl0Cj4gZG9lc24ndCBleGlzdCBvciB3aGF0 PwoKV2hhdCBleGFjdGx5IGRvIHlvdSBtZWFuIHdpdGggIm1peGVkIGVuZGlhbiI/ICBUaGUgcG93 ZXJwYyBjYXNlLCB3aGVyZQprZXJuZWwgKyB1c2Vyc3BhY2UgY2FuIHJ1biBpbiBlaXRoZXIgYmln IG9yIGxpdHRsZSBlbmRpYW4gbW9kZT8gIE9yCnNvbWV0aGluZyBlbHNlPwoKY2hlZXJzLAogIEdl cmQKCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fCmRyaS1k ZXZlbCBtYWlsaW5nIGxpc3QKZHJpLWRldmVsQGxpc3RzLmZyZWVkZXNrdG9wLm9yZwpodHRwczov L2xpc3RzLmZyZWVkZXNrdG9wLm9yZy9tYWlsbWFuL2xpc3RpbmZvL2RyaS1kZXZlbAo= From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1037490AbdDUJuY convert rfc822-to-8bit (ORCPT ); Fri, 21 Apr 2017 05:50:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53850 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1037472AbdDUJuV (ORCPT ); Fri, 21 Apr 2017 05:50:21 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com A5080A3294 Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=kraxel@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com A5080A3294 Message-ID: <1492768218.25675.33.camel@redhat.com> Subject: Re: [PATCH] drm: fourcc byteorder: brings header file comments in line with reality. From: Gerd Hoffmann To: Ville =?ISO-8859-1?Q?Syrj=E4l=E4?= Cc: dri-devel@lists.freedesktop.org, Daniel Vetter , Pekka Paalanen , Ilia Mirkin , Michel =?ISO-8859-1?Q?D=E4nzer?= , Alex Deucher , amd-gfx@lists.freedesktop.org, Jani Nikula , Sean Paul , David Airlie , open list Date: Fri, 21 Apr 2017 11:50:18 +0200 In-Reply-To: <20170421092530.GE30290@intel.com> References: <20170421075825.6307-1-kraxel@redhat.com> <20170421092530.GE30290@intel.com> 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 [10.5.110.39]); Fri, 21 Apr 2017 09:50:21 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fr, 2017-04-21 at 12:25 +0300, Ville Syrjälä wrote: > On Fri, Apr 21, 2017 at 09:58:24AM +0200, Gerd Hoffmann wrote: > > While working on graphics support for virtual machines on ppc64 (which > > exists in both little and big endian variants) I've figured the comments > > for various drm fourcc formats in the header file don't match reality. > > > > Comments says the RGB formats are little endian, but in practice they > > are native endian. Look at the drm_mode_legacy_fb_format() helper. It > > maps -- for example -- bpp/depth 32/24 to DRM_FORMAT_XRGB8888, no matter > > whenever the machine is little endian or big endian. The users of this > > function (fbdev emulation, DRM_IOCTL_MODE_ADDFB) expect the framebuffer > > is native endian, not little endian. Most userspace also operates on > > native endian only. > > I'm not a fan of "native". Native to what? "CPU" or "host" is what I'd > call it. native == whatever the cpu is using. I personally find "native" more intuitive, but at the end of the day I don't mind much. If people prefer "host" over "native" I'll change it. > And what about the mxied endian case? Are you just going to pretend it > doesn't exist or what? What exactly do you mean with "mixed endian"? The powerpc case, where kernel + userspace can run in either big or little endian mode? Or something else? cheers, Gerd