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by PhilE
Sat Nov 27, 2021 4:02 pm
Forum: Ubuntu
Topic: Device Tree Problem with RPi 4B and Ubuntu 20.04
Replies: 1
Views: 118

Re: Device Tree Problem with RPi 4B and Ubuntu 20.04

Please capture the state of the active Device Tree without the overlays. You can do the same with one of the overlays that shows the problem if you want. $ dtc -I fs -O dts -o live1.dts (change to live2.dts for a second snapshot. The files are a bit long to upload, so put them in pastebin or similar.
by PhilE
Fri Nov 26, 2021 5:24 pm
Forum: Advanced users
Topic: Moving Linux Kernel to 5.15
Replies: 92
Views: 6180

Re: Moving Linux Kernel to 5.15

xhci_hcd 0000:01:00.0: can't setup: -110 xhci_hcd 0000:01:00.0: USB bus 1 deregistered That's not a failure mode I recognise. -110 is -ETIMEDOUT, but other than that I don't know - other than rebooting without any USB devices attached and plugging them in later (as a diagnostic technique) I don't k...
by PhilE
Fri Nov 26, 2021 8:35 am
Forum: Compute Module
Topic: How to use MAX98357 with CM4?
Replies: 2
Views: 111

Re: How to use MAX98357 with CM4?

Yes, that's the way to go: pi@raspberrypi:~$ dtoverlay -h max98357a Name: max98357a Info: Configures the Maxim MAX98357A I2S DAC Usage: dtoverlay=max98357a,<param>=<val> Params: no-sdmode Driver does not manage the state of the DAC's SD_MODE pin (i.e. chip is always on). sdmode-pin integer, GPIO pin...
by PhilE
Thu Nov 25, 2021 5:56 pm
Forum: Troubleshooting
Topic: Pi Zero 2 W, libgpiod and defaults on GPIO pins on app exit
Replies: 21
Views: 466

Re: Pi Zero 2 W, libgpiod and defaults on GPIO pins on app exit

The 5.4 kernel is ancient history - I encourage you to switch to 5.10 if at all possible. Although we often have problems when transitioning to newer kernels, I can't remember it ever feeling like a step backwards by the time we've got it working.
by PhilE
Thu Nov 25, 2021 5:38 pm
Forum: Troubleshooting
Topic: Pi Zero 2 W, libgpiod and defaults on GPIO pins on app exit
Replies: 21
Views: 466

Re: Pi Zero 2 W, libgpiod and defaults on GPIO pins on app exit

1. I did answer this: Unfortunately there is a breaking change in the Zero 2 W DTB, kernel and firmware - some combinations of old and new don't work. The best way to test it would be using "sudo rpi-update" to apply the latest kernel and firmware, then overwrite the new .dtb. The incompat...
by PhilE
Thu Nov 25, 2021 4:59 pm
Forum: Compute Module
Topic: Custom PCB Bluetooth Issue
Replies: 25
Views: 708

Re: Custom PCB Bluetooth Issue

Aw shucks...
by PhilE
Thu Nov 25, 2021 4:27 pm
Forum: Troubleshooting
Topic: Pi Zero 2 W, libgpiod and defaults on GPIO pins on app exit
Replies: 21
Views: 466

Re: Pi Zero 2 W, libgpiod and defaults on GPIO pins on app exit

"sudo rpi-update" has access to newer kernels than "sudo apt update && sudo apt upgrade" - it's cutting edge, and not recommended for regular users unless advised to do so by a Raspberry Pi engineer. If you subsequently run "sudo apt update && sudo apt upgrad...
by PhilE
Thu Nov 25, 2021 3:51 pm
Forum: Troubleshooting
Topic: Pi Zero 2 W, libgpiod and defaults on GPIO pins on app exit
Replies: 21
Views: 466

Re: Pi Zero 2 W, libgpiod and defaults on GPIO pins on app exit

Unfortunately there is a breaking change in the Zero 2 W DTB, kernel and firmware - some combinations of old and new don't work. The best way to test it would be using "sudo rpi-update" to apply the latest kernel and firmware, then overwrite the new .dtb. If the Zero W works as expected wi...
by PhilE
Thu Nov 25, 2021 1:43 pm
Forum: Advanced users
Topic: Forcing the Pi4 bootloader messages to be shown on screen
Replies: 2
Views: 122

Re: [SOLVED]Forcing the Pi4 bootloader messages to be shown on screen

Or for less transient output, use `BOOT_UART=1` and connect a serial cable to GPIOs 14 & 15 (pins 8 & 10), configured for 115200 baud.
by PhilE
Thu Nov 25, 2021 1:23 pm
Forum: Advanced users
Topic: Network interface naming differences between Pi4 and Pi400
Replies: 3
Views: 136

Re: Network interface naming differences between Pi4 and Pi400

The quickest way to find the cause of the change would be to put a "WARN_ON(1);" in dev_change_name (net/core/dev.c).
by PhilE
Thu Nov 25, 2021 1:14 pm
Forum: Advanced users
Topic: Network interface naming differences between Pi4 and Pi400
Replies: 3
Views: 136

Re: Network interface naming differences between Pi4 and Pi400

There's a different WLAN chip on Pi 400 (43456 vs 43455) and Ethernet PHY, but other than that the differences are small at the kernel level. Most of the Device Tree differences are spurious, stemming from the fact that the 400 hasn't yet received patches from upstream (we should fix that). Even wit...
by PhilE
Thu Nov 25, 2021 10:39 am
Forum: Troubleshooting
Topic: Pi Zero 2 W, libgpiod and defaults on GPIO pins on app exit
Replies: 21
Views: 466

Re: Pi Zero 2 W, libgpiod and defaults on GPIO pins on app exit

Found it. An upstream commit added in kernel 5.7 bypasses the default pin claiming and releasing code if (to cut a long story short) a "pin-ranges" property is not present in the Device Tree declaration of the GPIO controller. Adding that property restores the expected behaviour. Please do...
by PhilE
Thu Nov 25, 2021 9:32 am
Forum: HATs and other add-ons
Topic: The future of HyperPixel 4 / DPI on Bullseye and beyond
Replies: 6
Views: 200

Re: The future of HyperPixel 4 / DPI on Bullseye and beyond

There's also something approaching documentation of gpio-fsm: viewtopic.php?p=1821505#p1821505
by PhilE
Thu Nov 25, 2021 8:40 am
Forum: Advanced users
Topic: Moving Linux Kernel to 5.15
Replies: 92
Views: 6180

Re: Moving Linux Kernel to 5.15

I think including ntfs3 in the kernel but not as default is the way to go.
Thanks - as a non-NTFS user the feedback is helpful. Having two filesystems that overlap so much is not ideal, but it sounds as though a hard transition is not going to work.
by PhilE
Wed Nov 24, 2021 8:30 pm
Forum: Advanced users
Topic: Moving Linux Kernel to 5.15
Replies: 92
Views: 6180

Re: Moving Linux Kernel to 5.15

I can't find those commits upstream - do you have commit hashes for them? Update: got them - they're in v5.16 (and rpi-5.16.y): e4165ae8304e drm/v3d: add multiple syncobjs support bb3425efdcd9 drm/v3d: add generic ioctl extension 07c2a41658c4 drm/v3d: alloc and init job in one shot 223583dd00a7 drm/...
by PhilE
Wed Nov 24, 2021 5:07 pm
Forum: Troubleshooting
Topic: Pi Zero 2 W, libgpiod and defaults on GPIO pins on app exit
Replies: 21
Views: 466

Re: Pi Zero 2 W, libgpiod and defaults on GPIO pins on app exit

I can confirm that simply reverting to a 5.4 kernel changes the behaviour back to what I would expect and what you want. Now to understand why.
by PhilE
Wed Nov 24, 2021 4:22 pm
Forum: Compute Module
Topic: Custom PCB Bluetooth Issue
Replies: 25
Views: 708

Re: Custom PCB Bluetooth Issue

Look inside bthelper - it's a shell script (wot I wrote) that includes the MAC address generation algorithm. You should also be able to instrument it with a few "echo" statements to pin down why it isn't working.
by PhilE
Wed Nov 24, 2021 4:19 pm
Forum: Troubleshooting
Topic: Pi Zero 2 W, libgpiod and defaults on GPIO pins on app exit
Replies: 21
Views: 466

Re: Pi Zero 2 W, libgpiod and defaults on GPIO pins on app exit

For "Bullseye" here read "newer image", which is equivalent to "new kernel" - I'm almost certain that only the kernel version makes a difference. We're on the same page.
by PhilE
Wed Nov 24, 2021 4:05 pm
Forum: Compute Module
Topic: Custom PCB Bluetooth Issue
Replies: 25
Views: 708

Re: Custom PCB Bluetooth Issue

Does running "sudo /usr/bin/bthelper hci0" manually set your address (or report anything interesting)? Or "sudo hcitool -i hci0 cmd 0x3f 0x001 0x01 0x23 0x45 0xeb 0x27 0xb8"?
by PhilE
Wed Nov 24, 2021 3:28 pm
Forum: Troubleshooting
Topic: Pi Zero 2 W, libgpiod and defaults on GPIO pins on app exit
Replies: 21
Views: 466

Re: Pi Zero 2 W, libgpiod and defaults on GPIO pins on app exit

What is a GPIO plus (and?) pinmux driver and where can I find this on the Raspbian? The Raspberry Pi kernel has a single driver that controls several things - alternate pin functions e.g. I2C, SPI and GPIO, pin pulls, and the direction and drive of GPIOs. Does this mean when the GPIO device is clos...
by PhilE
Wed Nov 24, 2021 3:21 pm
Forum: Compute Module
Topic: Custom PCB Bluetooth Issue
Replies: 25
Views: 708

Re: Custom PCB Bluetooth Issue

A BDADDR of AA:AA:AA:AA:AA:AA arises because the kernel Bluetooth initialisation doesn't have a way to pass in an address (as we normally do through hciattach). Instead there is (in Raspberru Pi OS, at least) a systemd service called bthelper@ that runs /usr/bin/bthelper, which in turn uses hcitool ...
by PhilE
Wed Nov 24, 2021 3:12 pm
Forum: HATs and other add-ons
Topic: The future of HyperPixel 4 / DPI on Bullseye and beyond
Replies: 6
Views: 200

Re: The future of HyperPixel 4 / DPI on Bullseye and beyond

The Linux kernel way is much like the UN*X way with utilities. UN*X gives you a set of tools that do one job well, and you are expected to use pipes and scripts to marshal them to perform your specific task. The kernel comprises a large number of driver modules that talk to their specific bits of ha...
by PhilE
Wed Nov 24, 2021 2:06 pm
Forum: Troubleshooting
Topic: Pi Zero 2 W, libgpiod and defaults on GPIO pins on app exit
Replies: 21
Views: 466

Re: Pi Zero 2 W, libgpiod and defaults on GPIO pins on app exit

The GPIO + pinmux driver has a method that is called when a GPIO is no longer being used. Its current action is to return the GPIO to being an input, which is particularly important when an alternate function has been selected because leaving it mapped can prevent it from being used on other pins. I...
by PhilE
Wed Nov 24, 2021 12:04 pm
Forum: Compute Module
Topic: Custom PCB Bluetooth Issue
Replies: 25
Views: 708

Re: Custom PCB Bluetooth Issue

I wasn't aware that there was an intermittent problem there. You could try adding "dtparam=krnbt" in config.txt to allow the kernel to initialise the BT modem, which will bypass the symbolic link (the corresponding /dev/ttyAMAx will no longer appear).
by PhilE
Wed Nov 24, 2021 11:09 am
Forum: Compute Module
Topic: rpiboot and exposing the SD card on a CM4 lite
Replies: 4
Views: 164

Re: rpiboot and exposing the SD card on a CM4 lite

The intermittent nature of the problem is really grating. No part of your post suggested the fault was intermittent. It should work every time, but you wouldn't believe how may problems are caused by dodgy USB cables and/or static discharge (there's a pair of shoes I can no longer wear to the offic...

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