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by jdb
Wed Jul 08, 2020 5:28 pm
Forum: General discussion
Topic: Updated raspi-config - Boot Eeprom options
Replies: 18
Views: 1121

Re: Updated raspi-config - Boot Eeprom options

USB booting is not yet officially released, so this is all unwarranted speculation, and probably 100% false! Locking!! and will be deleted soon. The options listed are in the raspi-config repo as of Monday. https://github.com/RPi-Distro/raspi-config/commit/18fc06bd34ee2c279204fdb8f9be512c931f625d U...
by jdb
Sun Jul 05, 2020 10:47 pm
Forum: General discussion
Topic: Raspberry Pi 4 8GB GPU Memory Split
Replies: 21
Views: 1419

Re: Raspberry Pi 4 8GB GPU Memory Split

If you're not going to bother spending time reading and understanding the responses provided to you in this thread by engineers that absolutely *do* know what they're talking about, don't be surprised if your thread gets locked.
by jdb
Sun Jul 05, 2020 7:11 pm
Forum: General discussion
Topic: Please improve the sound quality of the Raspberry Pi product.
Replies: 28
Views: 1687

Re: Please improve the sound quality of the Raspberry Pi product.

To summerize: a) the built-in device is very good, b) it is easy to use. I don't see there is anything to improve, at least in stereo mode. There are a few things about the PWM DAC that suck, and unfortunately are impossible to fix without re-implementing silicon and spending more money on the outp...
by jdb
Sun Jul 05, 2020 8:34 am
Forum: General discussion
Topic: Please improve the sound quality of the Raspberry Pi product.
Replies: 28
Views: 1687

Re: Please improve the sound quality of the Raspberry Pi product.

"Hey, a random youtuber claims your product has poor feature X, please fix" - the video itself offers no supporting evidence or even measurement of the supposed quality. What's a "polluted USB bus", anyway?
by jdb
Sat Jul 04, 2020 4:09 pm
Forum: General discussion
Topic: Raspberry Pi 4 8GB GPU Memory Split
Replies: 21
Views: 1419

Re: Raspberry Pi 4 8GB GPU Memory Split

So it begs the question, on a scalable system, why even have legacy restrictive settings like gpu_mem on the standard image in the first place? It would be part of the allocation procedure to make sure larger address spaces translate to < 4GB. (By PCIe I meant it is present in x86 systems. I wasn't...
by jdb
Sat Jul 04, 2020 8:06 am
Forum: General discussion
Topic: The Raspberry Pi 4 is missing one small connector
Replies: 10
Views: 584

Re: The Raspberry Pi 4 is missing one small connector

Feature request thread - locking.
by jdb
Fri Jul 03, 2020 10:25 pm
Forum: General discussion
Topic: MicroSD slowness
Replies: 22
Views: 1045

Re: MicroSD slowness

Random write speed 2 IOPS (target 500) - FAIL
I recommend that you buy a different SD card.
by jdb
Fri Jul 03, 2020 4:27 pm
Forum: General discussion
Topic: MicroSD slowness
Replies: 22
Views: 1045

Re: MicroSD slowness

What happens if you run the SD benchmark from the Agnostics utility in the desktop's apps menu? Assuming you are using Raspberry Pi OS, that is.
by jdb
Thu Jul 02, 2020 5:28 pm
Forum: General discussion
Topic: Is it possible to have a "cluster" of Raspberry Pis?
Replies: 107
Views: 3078

Re: A silly question perhaps

What is the specific barrier to the existence of such a device? You had it for example with the Hydra board on the RiscPC Speed x bandwidth. Gigabit is required at a minimum for a decent "server farm" cluster, in which individual jobs are farmed out to separate machines with independent operating s...
by jdb
Wed Jul 01, 2020 8:45 pm
Forum: General discussion
Topic: Overclocking past 2.147GHz on the Pi4
Replies: 16
Views: 1157

Re: Overclocking past 2.147GHz on the Pi4

The firmware's frequency_t type was defined as a signed 32-bit integer, for whatever reason. This means that setting a frequency >2^31 will wrap to an invalid value. (yes negative frequencies exist, and no, they are of no use in clock scaling). An improvement is in the works to allow setting frequen...
by jdb
Tue Jun 30, 2020 11:45 am
Forum: Troubleshooting
Topic: Fixing incorrect undervoltage warnings
Replies: 37
Views: 1603

Re: Fixing incorrect undervoltage warnings

Given that the PMIC is reporting healthy, and prior undervoltage has been recorded, it looks like the PMIC is doing its job. Provoke an undervoltage condition by lowering the bench supply down to ~4.63V, then see if the output of vcgencmd get_throttled changes. Sweep the range when monitoring the ge...
by jdb
Mon Jun 29, 2020 3:26 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Pi4 3.5mm audio out cuts off at 19kHz
Replies: 7
Views: 579

Re: Pi4 3.5mm audio out cuts off at 19kHz

You are seeing the roll-off of the 512-tap FIR lowpass filter implemented in firmware, not the PWM filter response. The filter chain takes any arbitrary input samplerate and converts it to a fixed 48.828kHz, before mixing all input sources together. Then there is an upsampling and noise shaping stag...
by jdb
Mon Jun 29, 2020 1:19 pm
Forum: Troubleshooting
Topic: USB Dongle no power on USB port after reboot on Raspberry Pi 4 model B
Replies: 4
Views: 240

Re: USB Dongle no power on USB port after reboot on Raspberry Pi 4 model B

What happens if you force a port power reset with uhubctl? Note that the version shipped in Raspbian isn't up to date and thus doesn't support Pi 4 port power switching. The source is located here: https://github.com/mvp/uhubctl Build instructions (follow the ones for "ubuntu") and instructions for ...
by jdb
Mon Jun 29, 2020 8:55 am
Forum: Troubleshooting
Topic: USB Dongle no power on USB port after reboot on Raspberry Pi 4 model B
Replies: 4
Views: 240

Re: USB Dongle no power on USB port after reboot

Does the behaviour change if you add "usbcore.old_scheme_first=Y" to /boot/cmdline.txt (and reboot)?
by jdb
Thu Jun 25, 2020 10:55 am
Forum: Advanced users
Topic: Problem with USB Speed
Replies: 8
Views: 429

Re: Problem with USB Speed

A single USB2.0 root port is shared between all downstream ports on a Pi 4. That is true for all models prior to RPi4B. It is certainly not the case on RPi4B that the two USB3.0 ports are downstream from a USB2.0 root hub. Incorrect. USB3.0 and USB2.0 are completely independent transports. USB3.0 c...
by jdb
Thu Jun 25, 2020 8:45 am
Forum: Advanced users
Topic: Problem with USB Speed
Replies: 8
Views: 429

Re: Problem with USB Speed

A single USB2.0 root port is shared between all downstream ports on a Pi 4.
by jdb
Wed Jun 24, 2020 2:30 pm
Forum: Advanced users
Topic: ELP 1080p USB camera failing
Replies: 9
Views: 457

Re: ELP 1080p USB camera failing

dmesg just dumps the entire contents of the kernel message buffer to standard output. Capturing all of it (as you are doing) is preferred.

What is the output with the camera plugged into the Pi?
by jdb
Wed Jun 24, 2020 12:56 pm
Forum: Advanced users
Topic: ELP 1080p USB camera failing
Replies: 9
Views: 457

Re: ELP 1080p USB camera failing

Your dmesg output doesn't appear to correspond to the lsusb - there are two missing USB3.0 hub entries.

Regardless, the USB2.0 portion of the hub is disconnecting from the Pi for whatever reason, and not successfully reconnecting.

What happens if you plug the camera directly into the Pi?
by jdb
Wed Jun 24, 2020 10:39 am
Forum: Advanced users
Topic: ELP 1080p USB camera failing
Replies: 9
Views: 457

Re: ELP 1080p USB camera failing

Split post from the sticky, since the issue is unrelated to firmware version.

What is the output of dmesg after the camera "disappears"?
by jdb
Wed Jun 24, 2020 10:22 am
Forum: Troubleshooting
Topic: VLI firmware v2.0 - powersaving features enabled
Replies: 117
Views: 34791

Re: VLI firmware v2.0 - powersaving features enabled

The difference is disabling powersaving completely, (0x40) or leaving L0s sleep state enabled (0x41). In theory, 0x40 should remove any performance impact from the latency added by low-power modes. 0137ad has a bug where 0x40 ends up having no effect and 0x41 does, but this is fixed in later versions.
by jdb
Mon Jun 22, 2020 6:15 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: thunderbolt adapter
Replies: 8
Views: 367

Re: thunderbolt adapter

64 channels of 44.1kHz audio is approximately 45 mbit/s. USB2.0 tops out at around 300mbit/s for periodic traffic. This is well within the capabilities of the USB2.0 OTG port, assuming you transfer all the data down a single endpoint. If you want 8 independent device streams, it's not going to be fe...
by jdb
Sat Jun 20, 2020 5:10 pm
Forum: General discussion
Topic: New RPi-VK-Driver low level driver
Replies: 15
Views: 2959

Re: New RPi-VK-Driver low level driver

B u m p

This looks shiny.
For the uninitiated: this is a Vulkan driver for Videocore IV - BCM2835/6/7.
by jdb
Wed Jun 17, 2020 6:05 pm
Forum: General discussion
Topic: Raspberry Pi 4 External Ram
Replies: 7
Views: 466

Re: Raspberry Pi 4 External Ram

Pokemonbulbasaur wrote:
Wed Jun 17, 2020 4:17 pm

I think Raspberry Pi should sell External Ram upgrades for raspberry pi 4's
Not happening.
Also this is a feature request thread, so locking.
by jdb
Sat Jun 13, 2020 7:05 pm
Forum: Troubleshooting
Topic: Overclocking a PI4 8GB doesn't boot
Replies: 5
Views: 291

Re: Overclocking a PI4 8GB doesn't boot

beerglass007 wrote:
Sat Jun 13, 2020 6:45 pm
When I edit the config.cfg file and add the following

over_voltage=6
arm_freq=2000

My RI4 doesn't boot

I'm running the latest OS with kernel 4.19 is this the problem ?

Thanks
What makes you think that those settings will work?
by jdb
Thu Jun 11, 2020 11:59 am
Forum: Advanced users
Topic: lspci cannot work, so should it even be present?
Replies: 8
Views: 24874

Re: lspci cannot work, so should it even be present?

Wow, a 6 year necro. Locking.

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