From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= Subject: Re: [PATCH] drm: fourcc byteorder: brings header file comments in line with reality. Date: Fri, 21 Apr 2017 14:05:56 +0300 Message-ID: <20170421110556.GG30290@intel.com> References: <20170421075825.6307-1-kraxel@redhat.com> <20170421092530.GE30290@intel.com> <1492768218.25675.33.camel@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Content-Disposition: inline In-Reply-To: <1492768218.25675.33.camel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> List-Id: Discussion list for AMD gfx List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: amd-gfx-bounces-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org Sender: "amd-gfx" To: Gerd Hoffmann Cc: Jani Nikula , David Airlie , Michel =?iso-8859-1?Q?D=E4nzer?= , open list , dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, Pekka Paalanen , Sean Paul , amd-gfx-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, Alex Deucher , Daniel Vetter , Ilia Mirkin T24gRnJpLCBBcHIgMjEsIDIwMTcgYXQgMTE6NTA6MThBTSArMDIwMCwgR2VyZCBIb2ZmbWFubiB3 cm90ZToKPiBPbiBGciwgMjAxNy0wNC0yMSBhdCAxMjoyNSArMDMwMCwgVmlsbGUgU3lyasOkbMOk IHdyb3RlOgo+ID4gT24gRnJpLCBBcHIgMjEsIDIwMTcgYXQgMDk6NTg6MjRBTSArMDIwMCwgR2Vy ZCBIb2ZmbWFubiB3cm90ZToKPiA+ID4gV2hpbGUgd29ya2luZyBvbiBncmFwaGljcyBzdXBwb3J0 IGZvciB2aXJ0dWFsIG1hY2hpbmVzIG9uIHBwYzY0ICh3aGljaAo+ID4gPiBleGlzdHMgaW4gYm90 aCBsaXR0bGUgYW5kIGJpZyBlbmRpYW4gdmFyaWFudHMpIEkndmUgZmlndXJlZCB0aGUgY29tbWVu dHMKPiA+ID4gZm9yIHZhcmlvdXMgZHJtIGZvdXJjYyBmb3JtYXRzIGluIHRoZSBoZWFkZXIgZmls ZSBkb24ndCBtYXRjaCByZWFsaXR5Lgo+ID4gPiAKPiA+ID4gQ29tbWVudHMgc2F5cyB0aGUgUkdC IGZvcm1hdHMgYXJlIGxpdHRsZSBlbmRpYW4sIGJ1dCBpbiBwcmFjdGljZSB0aGV5Cj4gPiA+IGFy ZSBuYXRpdmUgZW5kaWFuLiAgTG9vayBhdCB0aGUgZHJtX21vZGVfbGVnYWN5X2ZiX2Zvcm1hdCgp IGhlbHBlci4gIEl0Cj4gPiA+IG1hcHMgLS0gZm9yIGV4YW1wbGUgLS0gYnBwL2RlcHRoIDMyLzI0 IHRvIERSTV9GT1JNQVRfWFJHQjg4ODgsIG5vIG1hdHRlcgo+ID4gPiB3aGVuZXZlciB0aGUgbWFj aGluZSBpcyBsaXR0bGUgZW5kaWFuIG9yIGJpZyBlbmRpYW4uICBUaGUgdXNlcnMgb2YgdGhpcwo+ ID4gPiBmdW5jdGlvbiAoZmJkZXYgZW11bGF0aW9uLCBEUk1fSU9DVExfTU9ERV9BRERGQikgZXhw ZWN0IHRoZSBmcmFtZWJ1ZmZlcgo+ID4gPiBpcyBuYXRpdmUgZW5kaWFuLCBub3QgbGl0dGxlIGVu ZGlhbi4gIE1vc3QgdXNlcnNwYWNlIGFsc28gb3BlcmF0ZXMgb24KPiA+ID4gbmF0aXZlIGVuZGlh biBvbmx5Lgo+ID4gCj4gPiBJJ20gbm90IGEgZmFuIG9mICJuYXRpdmUiLiBOYXRpdmUgdG8gd2hh dD8gIkNQVSIgb3IgImhvc3QiIGlzIHdoYXQgSSdkCj4gPiBjYWxsIGl0Lgo+IAo+IG5hdGl2ZSA9 PSB3aGF0ZXZlciB0aGUgY3B1IGlzIHVzaW5nLgo+IAo+IEkgcGVyc29uYWxseSBmaW5kICJuYXRp dmUiIG1vcmUgaW50dWl0aXZlLCBidXQgYXQgdGhlIGVuZCBvZiB0aGUgZGF5IEkKPiBkb24ndCBt aW5kIG11Y2guICBJZiBwZW9wbGUgcHJlZmVyICJob3N0IiBvdmVyICJuYXRpdmUiIEknbGwgY2hh bmdlIGl0Lgo+IAo+ID4gQW5kIHdoYXQgYWJvdXQgdGhlIG14aWVkIGVuZGlhbiBjYXNlPyBBcmUg eW91IGp1c3QgZ29pbmcgdG8gcHJldGVuZCBpdAo+ID4gZG9lc24ndCBleGlzdCBvciB3aGF0Pwo+ IAo+IFdoYXQgZXhhY3RseSBkbyB5b3UgbWVhbiB3aXRoICJtaXhlZCBlbmRpYW4iPyAgVGhlIHBv d2VycGMgY2FzZSwgd2hlcmUKPiBrZXJuZWwgKyB1c2Vyc3BhY2UgY2FuIHJ1biBpbiBlaXRoZXIg YmlnIG9yIGxpdHRsZSBlbmRpYW4gbW9kZT8gIE9yCj4gc29tZXRoaW5nIGVsc2U/CgpCaWcgZW5k aWFuIENQVSBhbmQgbGl0dGxlIGVuZGlhbiBHUFUuIEkgdGhpbmsgdGhhdCBzaG91bGQgYmUgdGhl IG1vc3QKY29tbW9uIGNhc2UgdGhlc2UgZGF5cy4KCi0tIApWaWxsZSBTeXJqw6Rsw6QKSW50ZWwg T1RDCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fCmFtZC1n ZnggbWFpbGluZyBsaXN0CmFtZC1nZnhAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCmh0dHBzOi8vbGlz dHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vYW1kLWdmeAo= From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1038274AbdDULGF (ORCPT ); Fri, 21 Apr 2017 07:06:05 -0400 Received: from mga04.intel.com ([192.55.52.120]:18692 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1038118AbdDULGC (ORCPT ); Fri, 21 Apr 2017 07:06:02 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.37,229,1488873600"; d="scan'208";a="1138527291" Date: Fri, 21 Apr 2017 14:05:56 +0300 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Gerd Hoffmann 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 Subject: Re: [PATCH] drm: fourcc byteorder: brings header file comments in line with reality. Message-ID: <20170421110556.GG30290@intel.com> References: <20170421075825.6307-1-kraxel@redhat.com> <20170421092530.GE30290@intel.com> <1492768218.25675.33.camel@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1492768218.25675.33.camel@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 21, 2017 at 11:50:18AM +0200, Gerd Hoffmann wrote: > 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? Big endian CPU and little endian GPU. I think that should be the most common case these days. -- Ville Syrjälä Intel OTC