Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1631486

Re: [PATCH 3/6] drm: fourcc byteorder: add bigendian support to drm_mode_legacy_fb_format

From Ville Syrjälä <ville.syrjala@linux.intel.com>
Newsgroups linux.kernel
Subject Re: [PATCH 3/6] drm: fourcc byteorder: add bigendian support to drm_mode_legacy_fb_format
Date 2017-04-26 16:40 +0200
Message-ID <tAwgO-3vw-3@gated-at.bofh.it> (permalink)
References <tzFFv-3rT-3@gated-at.bofh.it> <tzFFv-3rT-1@gated-at.bofh.it> <tzZbb-7xO-13@gated-at.bofh.it> <tA5qh-31F-13@gated-at.bofh.it> <tAkyZ-4lo-1@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


On Wed, Apr 26, 2017 at 11:00:09AM +0900, Michel Dänzer wrote:
> On 25/04/17 06:52 PM, Ville Syrjälä wrote:
> > On Tue, Apr 25, 2017 at 12:18:52PM +0900, Michel Dänzer wrote:
> >> On 24/04/17 03:25 PM, Gerd Hoffmann wrote:
> >>> +#ifdef __BIG_ENDIAN
> >>> +	switch (bpp) {
> >>> +	case 8:
> >>> +		fmt = DRM_FORMAT_C8;
> >>> +		break;
> >>> +	case 24:
> >>> +		fmt = DRM_FORMAT_BGR888;
> >>> +		break;
> >>
> >> BTW, endianness as a concept cannot apply to 8 or 24 bpp formats.
> > 
> > To 8bpp no, but it can easily apply to 24bpp.
> 
> Any byte swapping rips apart the bytes of a 24bpp pixel, so those
> formats only make sense as straight array formats.

In my book little endian just means "lsb is stored in the lowest
memory address". The fact that your CPU/GPU can't do 3 byte swaps
is not relevant for that definition IMO.

-- 
Ville Syrjälä
Intel OTC

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

Re: [PATCH 3/6] drm: fourcc byteorder: add bigendian support to  drm_mode_legacy_fb_format Michel Dänzer <michel@daenzer.net> - 2017-04-25 05:20 +0200
  Re: [PATCH 3/6] drm: fourcc byteorder: add bigendian support to  drm_mode_legacy_fb_format Ville Syrjälä <ville.syrjala@linux.intel.com> - 2017-04-25 12:00 +0200
    Re: [PATCH 3/6] drm: fourcc byteorder: add bigendian support to  drm_mode_legacy_fb_format Michel Dänzer <michel@daenzer.net> - 2017-04-26 04:10 +0200
      Re: [PATCH 3/6] drm: fourcc byteorder: add bigendian support to  drm_mode_legacy_fb_format Ville Syrjälä <ville.syrjala@linux.intel.com> - 2017-04-26 16:40 +0200
  Re: [PATCH 3/6] drm: fourcc byteorder: add bigendian support to  drm_mode_legacy_fb_format Gerd Hoffmann <kraxel@redhat.com> - 2017-04-26 08:00 +0200
    Re: [PATCH 3/6] drm: fourcc byteorder: add bigendian support to  drm_mode_legacy_fb_format Michel Dänzer <michel@daenzer.net> - 2017-04-26 11:40 +0200
      Re: [PATCH 3/6] drm: fourcc byteorder: add bigendian support to  drm_mode_legacy_fb_format Gerd Hoffmann <kraxel@redhat.com> - 2017-04-26 14:20 +0200
        Re: [PATCH 3/6] drm: fourcc byteorder: add bigendian support to  drm_mode_legacy_fb_format Michel Dänzer <michel@daenzer.net> - 2017-04-27 03:00 +0200
          Re: [PATCH 3/6] drm: fourcc byteorder: add bigendian support to  drm_mode_legacy_fb_format Gerd Hoffmann <kraxel@redhat.com> - 2017-04-27 08:50 +0200
            Re: [PATCH 3/6] drm: fourcc byteorder: add bigendian support to  drm_mode_legacy_fb_format Michel Dänzer <michel@daenzer.net> - 2017-04-27 09:10 +0200
              Re: [PATCH 3/6] drm: fourcc byteorder: add bigendian support to  drm_mode_legacy_fb_format Gerd Hoffmann <kraxel@redhat.com> - 2017-04-28 12:10 +0200
    Re: [PATCH 3/6] drm: fourcc byteorder: add bigendian support to  drm_mode_legacy_fb_format Eric Engestrom <eric.engestrom@imgtec.com> - 2017-04-26 15:30 +0200
      Re: [PATCH 3/6] drm: fourcc byteorder: add bigendian support to  drm_mode_legacy_fb_format Gerd Hoffmann <kraxel@redhat.com> - 2017-04-26 16:00 +0200

csiph-web