From: Daniel Vetter <daniel@ffwll.ch>
To: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Linux Fbdev development list <linux-fbdev@vger.kernel.org>,
David Airlie <airlied@linux.ie>,
Michael Ellerman <mpe@ellerman.id.au>,
Helge Deller <deller@gmx.de>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>,
Javier Martinez Canillas <javierm@redhat.com>,
DRI Development <dri-devel@lists.freedesktop.org>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Maxime Ripard <maxime@cerno.tech>,
Paul Mackerras <paulus@samba.org>,
Michal Suchanek <msuchanek@suse.de>,
Sam Ravnborg <sam@ravnborg.org>
Subject: Re: [PATCH v2 04/10] drm/simpledrm: Compute framebuffer stride if not set
Date: Tue, 6 Sep 2022 21:16:54 +0200 [thread overview]
Message-ID: <YxecprE8c8pwy5PB@phenom.ffwll.local> (raw)
In-Reply-To: <b22b363c-187b-0783-32ab-f9683af2e20a@suse.de>
On Thu, Aug 11, 2022 at 08:27:42PM +0200, Thomas Zimmermann wrote:
>
>
> Am 11.08.22 um 20:26 schrieb Thomas Zimmermann:
> > Hi Daniel
> >
> > Am 11.08.22 um 19:23 schrieb Daniel Vetter:
> > > On Wed, 27 Jul 2022 at 09:53, Thomas Zimmermann
> > > <tzimmermann@suse.de> wrote:
> > > >
> > > > Hi
> > > >
> > > > Am 25.07.22 um 17:13 schrieb Javier Martinez Canillas:
> > > > > Hello Geert,
> > > > >
> > > > > On 7/21/22 16:46, Geert Uytterhoeven wrote:
> > > > > > Hi Thomas,
> > > > > >
> > > > > > On Wed, Jul 20, 2022 at 4:27 PM Thomas Zimmermann
> > > > > > <tzimmermann@suse.de> wrote:
> > > > > > > Compute the framebuffer's scanline stride length if not given by
> > > > > > > the simplefb data.
> > > > > > >
> > > > > > > Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> > > > > >
> > > > > > Thanks for your patch!
> > > > > >
> > > > > > > --- a/drivers/gpu/drm/tiny/simpledrm.c
> > > > > > > +++ b/drivers/gpu/drm/tiny/simpledrm.c
> > > > > > > @@ -743,6 +743,9 @@ static struct simpledrm_device
> > > > > > > *simpledrm_device_create(struct drm_driver *drv,
> > > > > > > drm_err(dev, "no simplefb configuration found\n");
> > > > > > > return ERR_PTR(-ENODEV);
> > > > > > > }
> > > > > > > + if (!stride)
> > > > > > > + stride = format->cpp[0] * width;
> > > > > >
> > > > > > DIV_ROUND_UP(drm_format_info_bpp(format) * width, 8)
> > > > > >
> > > > >
> > > > > I think you meant here:
> > > > >
> > > > > DIV_ROUND_UP(drm_format_info_bpp(format, 0) * width, 8) ?
> > > >
> > > > I guess, that's the right function. My original code is correct, but cpp
> > > > is also deprecated.
> > >
> > > You all mean drm_format_info_min_pitch().
> >
> > Thanks a lot. I wasn't even aware of this function, but I had almost
> > written my own implementation of it. I'll update the patch accordingly.
>
> Arghh, too late. I merged that patch already.
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Preemptively, if you can do the fixup patch (and it's not yet merged)?
-Daniel
>
> >
> > Best regards
> > Thomas
> >
> > >
> > > I really don't want drivers to go grab any of the legacy format info
> > > fields like bpp or depth. switch() statements on the fourcc code for
> > > programming registers, or one of the real helper functions in
> > > drm_fourcc.c (there might be some gaps), but not ever going through
> > > legacy concepts. Anything else just leads to subtle bugs when new
> > > formats get added and oops suddenly the assumptions don't hold.
> > >
> > > Those should be strictly limited to legacy (i.e. not drm_fourcc aware)
> > > interfaces. Heck I think even fbdev emulation should completely switch
> > > over to drm_fourcc/drm_format_info, but alas that's a pile of work and
> > > not much payoff.
> > >
> > > I'm trying to volunteer Same to add a legacy_bpp tag to the above
> > > helper and appropriately limit it, I think limiting to formats with
> > > depth!=0 is probably the right thing. And then we should probably
> > > remove a pile of the cargo-culted depth!=0 entries too.
> > > -Daniel
> > >
> > > >
> > > > Best regards
> > > > Thomas
> > > >
> > > > >
> > > > > With that change,
> > > > >
> > > > > Acked-by: Javier Martinez Canillas <javierm@redhat.com>
> > > > >
> > > >
> > > > --
> > > > Thomas Zimmermann
> > > > Graphics Driver Developer
> > > > SUSE Software Solutions Germany GmbH
> > > > Maxfeldstr. 5, 90409 Nürnberg, Germany
> > > > (HRB 36809, AG Nürnberg)
> > > > Geschäftsführer: Ivo Totev
> > >
> > >
> > >
> >
>
> --
> Thomas Zimmermann
> Graphics Driver Developer
> SUSE Software Solutions Germany GmbH
> Maxfeldstr. 5, 90409 Nürnberg, Germany
> (HRB 36809, AG Nürnberg)
> Geschäftsführer: Ivo Totev
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
next prev parent reply other threads:[~2022-09-06 19:17 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-20 14:27 [PATCH v2 00/10] drm: Add driver for PowerPC OF displays Thomas Zimmermann
2022-07-20 14:27 ` [PATCH v2 01/10] drm/simpledrm: Remove mem field from device structure Thomas Zimmermann
2022-07-25 14:48 ` Javier Martinez Canillas
2022-07-20 14:27 ` [PATCH v2 02/10] drm/simpledrm: Inline device-init helpers Thomas Zimmermann
2022-07-25 15:01 ` Javier Martinez Canillas
2022-07-27 7:50 ` Thomas Zimmermann
2022-07-27 9:30 ` Javier Martinez Canillas
2022-07-20 14:27 ` [PATCH v2 03/10] drm/simpledrm: Remove pdev field from device structure Thomas Zimmermann
2022-07-25 15:02 ` Javier Martinez Canillas
2022-07-20 14:27 ` [PATCH v2 04/10] drm/simpledrm: Compute framebuffer stride if not set Thomas Zimmermann
2022-07-21 14:46 ` Geert Uytterhoeven
2022-07-25 15:13 ` Javier Martinez Canillas
2022-07-27 7:53 ` Thomas Zimmermann
2022-08-11 17:23 ` Daniel Vetter
2022-08-11 18:26 ` Thomas Zimmermann
2022-08-11 18:27 ` Thomas Zimmermann
2022-09-06 19:16 ` Daniel Vetter [this message]
2022-07-20 14:27 ` [PATCH v2 05/10] drm/simpledrm: Convert to atomic helpers Thomas Zimmermann
2022-07-25 15:46 ` Javier Martinez Canillas
2022-07-27 7:58 ` Thomas Zimmermann
2022-07-20 14:27 ` [PATCH v2 06/10] drm/simpledrm: Move some functionality into fwfb helper library Thomas Zimmermann
2022-07-25 16:23 ` Javier Martinez Canillas
2022-07-27 8:24 ` Thomas Zimmermann
2022-07-27 9:39 ` Javier Martinez Canillas
2022-07-20 14:27 ` [PATCH v2 07/10] drm/ofdrm: Add ofdrm for Open Firmware framebuffers Thomas Zimmermann
2022-07-26 13:17 ` Javier Martinez Canillas
2022-09-21 11:41 ` Thomas Zimmermann
2022-07-20 14:27 ` [PATCH v2 08/10] drm/ofdrm: Add CRTC state Thomas Zimmermann
2022-07-26 13:36 ` Javier Martinez Canillas
2022-09-21 11:45 ` Thomas Zimmermann
2022-07-20 14:27 ` [PATCH v2 09/10] drm/ofdrm: Add per-model device function Thomas Zimmermann
2022-07-26 13:38 ` Javier Martinez Canillas
2022-07-26 14:40 ` Michal Suchánek
2022-07-26 19:22 ` Javier Martinez Canillas
2022-07-27 8:33 ` Thomas Zimmermann
2022-08-05 0:22 ` Benjamin Herrenschmidt
2022-09-21 12:37 ` Thomas Zimmermann
2022-07-20 14:27 ` [PATCH v2 10/10] drm/ofdrm: Support color management Thomas Zimmermann
2022-07-26 13:49 ` Javier Martinez Canillas
2022-07-27 8:41 ` Thomas Zimmermann
2022-07-27 9:45 ` Javier Martinez Canillas
2022-08-05 0:29 ` Benjamin Herrenschmidt
2022-08-05 0:19 ` Benjamin Herrenschmidt
2022-09-21 12:55 ` Thomas Zimmermann
2022-09-21 16:48 ` Geert Uytterhoeven
2022-09-22 6:42 ` Thomas Zimmermann
2022-09-22 7:28 ` Maxime Ripard
2022-09-22 8:06 ` Thomas Zimmermann
2022-07-28 11:13 ` [PATCH v2 00/10] drm: Add driver for PowerPC OF displays Michael Ellerman
2022-07-28 11:31 ` Michal Suchánek
2022-07-28 11:42 ` Thomas Zimmermann
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