notro

/*
 * Device Tree overlay for fbtft drivers
 */

/dts-v1/;
/plugin/;

/ {
	compatible = "brcm,bcm2835";

notro

From bcea026824853572ef100dafb23ac2a3b6bd9fc8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= <noralf@tronnes.org>
Date: Mon, 19 Jul 2021 18:23:14 +0200
Subject: [PATCH 5/5] connector: Add new DRM connector types
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
---

notro

I used ftrace to try and find where the problem is, and have tracked it to spi-bcm2835.

Pi4 spends 19.907 ms sending the pixel data and Pi zero spends 29.990 ms.

trace-cmd is available on the 'pi' image.

Pi4
---

# trace-cmd record -o /tmp/trace.dat -p function_graph -l mipi_dbi_fb_dirty -l spi_transfer_one_message

notro

Host: Raspberry Pi 4
Device: Raspberry Pi Zero

SPI speed: 66.6MHz (spi_hz=70000000 clk_hz=400000000 => cdiv=6 => effective_speed_hz=66666666)
(see bcm2835_spi_transfer_one() for details)


pi@pi4:~ $ sudo python3 ~/work/projects/notro-gud/tests/perf.py -f RGB565 -i 50
Iterations: 50

notro

Host: Raspberry Pi 4
Device: Raspberry Pi 4

SPI speed: 62.5MHz (spi_hz=70000000 clk_hz=500000000 => cdiv=8 => effective_speed_hz=62500000)
(see bcm2835_spi_transfer_one() for details)


pi@pi4:~ $ sudo python3 ~/work/projects/notro-gud/tests/perf.py -f RGB565 -i 50
Iterations: 50

notro

Host: Raspberry Pi 4
Device: Raspberry Pico pico-display

pi@pi4:~ $ sudo python3 ~/work/projects/notro-gud/tests/perf.py -i 50
Iterations: 50

240x135-0@RGB565
  No compress : 15.1 > 14.8 > 14.3 fps (67.614 ms)
  Compress  x0: 14.7 > 14.1 > 14.0 fps (70.838 ms)
  Compress  x1: 15.0 > 14.2 > 14.1 fps (70.185 ms)

notro

Host: Raspberry Pi 4
Device: Raspberry Pico RPi-Display

pi@pi4:~ $ sudo python3 ~/work/projects/notro-gud/tests/perf.py -i 50
Iterations: 50

320x240-0@RGB565
  No compress :  6.3 >  6.2 >  6.1 fps (162.383 ms) (split:2)
  Compress  x0:  6.2 >  6.1 >  6.0 fps (164.444 ms) (split:2)
  Compress  x1:  6.0 >  5.9 >  5.8 fps (168.977 ms) (split:2)

notro

Host: Raspberry Pi 4
Device: Raspberry Pi 4

pi@pi4:~ $ sudo python3 ~/work/projects/notro-gud/tests/perf.py -i 50
Iterations: 50

1920x1080-60@XRGB8888
  No compress :  3.8 >  3.5 >  3.5 fps (283.704 ms) (split:2)
  Compress  x0:  3.2 >  3.1 >  2.8 fps (327.705 ms) (split:2)
  Compress  x1:  3.2 >  3.0 >  2.8 fps (331.469 ms) (split:2)

notro

Host: Raspberry Pi 4
Device: Raspberry Pi Zero

pi@pi4:~ $ sudo python3 ~/work/projects/notro-gud/tests/perf.py -i 50
Iterations: 50

1920x1080-60@XRGB8888
  No compress :  3.4 >  3.2 >  3.1 fps (314.599 ms) (split:2)
  Compress  x0:  3.2 >  3.0 >  2.7 fps (333.485 ms) (split:2)
  Compress  x1:  3.2 >  3.0 >  2.7 fps (334.175 ms) (split:2)

notro

Host: Raspberry Pi 4
Device: Rock Pi 4

pi@pi4:~ $ sudo python3 ~/work/projects/notro-gud/tests/perf.py -i 50
Iterations: 50

1920x1080-60@XRGB8888
  No compress : 10.3 >  9.5 >  8.9 fps (105.401 ms) (split:2)
  Compress  x0:  6.9 >  6.9 >  6.9 fps (145.269 ms) (split:2)
  Compress  x1:  6.9 >  6.9 >  6.8 fps (145.292 ms) (split:2)