Hi Javier,
On Fri, Feb 4, 2022 at 2:43 PM Javier Martinez Canillas
<javierm@xxxxxxxxxx> wrote:
> This patch series adds a DRM driver for the Solomon OLED SSD1305, SSD1306,
> SSD1307 and SSD1309 displays. It is a port of the ssd1307fb fbdev driver.
I gave it a try on an Adafruit FeatherWing 128x32 OLED, connected to an
OrangeCrab ECP5 FPGA board running a 64 MHz VexRiscv RISC-V softcore.
Findings:
- Kernel size increased by 349 KiB,
- The "Memory:" line reports 412 KiB less memory,
- On top of that, "free" shows ca. 92 KiB more memory in use after
bootup.
- The logo (I have a custom monochrome logo enabled) is no longer shown.
- The screen is empty, with a (very very slow) flashing cursor in the
middle of the screen, with a bogus long line next to it, which I can
see being redrawn.
- Writing text (e.g. hello) to /dev/tty0, I first see the text,
followed by an enlargement of some of the characters.
- "time ls" on the serial console (no files in the current directory,
so nothing to print) increases from 0.86s to 1.92s, so the system is
more loaded. As ssd1307fb relied on deferred I/O too, the slowdown
might be (partly) due to redrawing of the visual artefacts
mentioned above.
So while the displays seems to be initialized correctly, it looks like
there are some serious bugs in the conversion from xrgb8888 to
monochrome.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
