From: Ilia Mirkin <imirkin@alum.mit.edu>
To: Thomas Zimmermann <tzimmermann@suse.de>
Cc: "Javier Martinez Canillas" <javierm@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
linux-fbdev <linux-fbdev@vger.kernel.org>,
"David Airlie" <airlied@linux.ie>,
"Daniel Vetter" <daniel.vetter@ffwll.ch>,
dri-devel <dri-devel@lists.freedesktop.org>,
"Noralf Trønnes" <noralf@tronnes.org>,
"Geert Uytterhoeven" <geert@linux-m68k.org>,
"Maxime Ripard" <maxime@cerno.tech>,
"Andy Shevchenko" <andriy.shevchenko@linux.intel.com>,
"Sam Ravnborg" <sam@ravnborg.org>
Subject: Re: [PATCH v2 1/4] drm/format-helper: Add drm_fb_{xrgb8888,gray8}_to_mono_reversed()
Date: Fri, 4 Feb 2022 16:02:08 -0500 [thread overview]
Message-ID: <CAKb7UvgxhLFT4aqYSE+=dpqfuTkvr62tsGmQP5H46mAytaQBRg@mail.gmail.com> (raw)
In-Reply-To: <47100413-db63-1efa-45e9-028dfc430b7e@suse.de>
On Fri, Feb 4, 2022 at 10:53 AM Thomas Zimmermann <tzimmermann@suse.de> wrote:
>
> Hi
>
> Am 04.02.22 um 14:43 schrieb Javier Martinez Canillas:
> > Add support to convert XR24 and 8-bit grayscale to reversed monochrome for
> > drivers that control monochromatic panels, that only have 1 bit per pixel.
> >
> > The drm_fb_gray8_to_mono_reversed() helper was based on the function that
> > does the same in the drivers/gpu/drm/tiny/repaper.c driver.
> >
> > Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
> > ---
> >
> > (no changes since v1)
> >
> > drivers/gpu/drm/drm_format_helper.c | 80 +++++++++++++++++++++++++++++
> > include/drm/drm_format_helper.h | 7 +++
> > 2 files changed, 87 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c
> > index 0f28dd2bdd72..cdce4b7c25d9 100644
> > --- a/drivers/gpu/drm/drm_format_helper.c
> > +++ b/drivers/gpu/drm/drm_format_helper.c
> > @@ -584,3 +584,83 @@ int drm_fb_blit_toio(void __iomem *dst, unsigned int dst_pitch, uint32_t dst_for
> > return -EINVAL;
> > }
> > EXPORT_SYMBOL(drm_fb_blit_toio);
> > +
> > +static void drm_fb_gray8_to_mono_reversed_line(u8 *dst, const u8 *src, size_t pixels)
> > +{
> > + unsigned int xb, i;
> > +
> > + for (xb = 0; xb < pixels / 8; xb++) {
>
> In practice, all mode widths are multiples of 8 because VGA mandated it.
> So it's ok-ish to assume this here. You should probably at least print a
> warning somewhere if (pixels % 8 != 0)
Not sure if it's relevant, but 1366x768 was a fairly popular laptop
resolution. There's even a dedicated drm_mode_fixup_1366x768 in
drm_edid.c. (Would it have killed them to add 2 more horizontal
pixels? Apparently.)
Cheers,
-ilia
next prev parent reply other threads:[~2022-02-04 21:02 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-04 13:43 [PATCH v2 0/4] drm/tiny: Add driver for Solomon SSD1307 OLED displays Javier Martinez Canillas
2022-02-04 13:43 ` [PATCH v2 1/4] drm/format-helper: Add drm_fb_{xrgb8888,gray8}_to_mono_reversed() Javier Martinez Canillas
2022-02-04 15:52 ` Thomas Zimmermann
2022-02-04 16:00 ` Thomas Zimmermann
2022-02-04 19:31 ` Javier Martinez Canillas
2022-02-04 20:35 ` Thomas Zimmermann
2022-02-04 21:02 ` Ilia Mirkin [this message]
2022-02-07 12:44 ` [PATCH v2 1/4] drm/format-helper: Add drm_fb_{xrgb8888, gray8}_to_mono_reversed() Thomas Zimmermann
2022-02-04 13:43 ` [PATCH v2 2/4] drm/tiny: Add driver for Solomon SSD130X OLED displays Javier Martinez Canillas
2022-02-04 14:26 ` Andy Shevchenko
2022-02-04 19:19 ` Javier Martinez Canillas
2022-02-05 13:04 ` Andy Shevchenko
2022-02-05 17:40 ` Javier Martinez Canillas
2022-02-04 13:43 ` [PATCH v2 3/4] MAINTAINERS: Add entry for Solomon SSD130X OLED displays DRM driver Javier Martinez Canillas
2022-02-04 13:57 ` Andy Shevchenko
2022-02-04 14:12 ` Javier Martinez Canillas
2022-02-04 14:28 ` Andy Shevchenko
2022-02-04 14:33 ` Javier Martinez Canillas
2022-02-04 13:43 ` [PATCH v2 4/4] dt-bindings: display: ssd1307fb: Add myself as binding co-maintainer Javier Martinez Canillas
2022-02-09 22:14 ` Rob Herring
2022-02-04 14:31 ` [PATCH v2 0/4] drm/tiny: Add driver for Solomon SSD1307 OLED displays Geert Uytterhoeven
2022-02-04 14:37 ` Javier Martinez Canillas
2022-02-08 14:19 ` Geert Uytterhoeven
2022-02-08 15:10 ` Javier Martinez Canillas
2022-02-08 15:18 ` Mark Brown
2022-02-08 15:32 ` Javier Martinez Canillas
2022-02-08 15:23 ` Geert Uytterhoeven
2022-02-08 15:40 ` Javier Martinez Canillas
2022-02-08 17:19 ` Javier Martinez Canillas
2022-02-09 13:47 ` Andy Shevchenko
2022-02-09 14:27 ` Geert Uytterhoeven
2022-02-09 14:42 ` Javier Martinez Canillas
2022-02-09 15:32 ` Andy Shevchenko
2022-02-10 8:32 ` Maxime Ripard
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