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by jdb
Tue Feb 18, 2020 6:10 pm
Forum: Advanced users
Topic: Can anyone help by providing lsusb output
Replies: 9
Views: 265

Re: Can anyone help by providing lsusb output

@hippy and @neilgl: I think the 4B behaviour is because the boot firmware now disables the SoC's built in USB controller for power saving reasons so there's nothing to detect. Again useful to have that confirmed. Pi 4B by default does not load an otg USB host driver in the base device tree. By impl...
by jdb
Mon Feb 17, 2020 1:21 pm
Forum: Troubleshooting
Topic: Not enough bandwidth for new device state.
Replies: 3
Views: 268

Re: Not enough bandwidth for new device state.

What happens if you put a USB2.0 hub between the Pi and your devices - can you use more of them if the devices are plugged into the hub?
by jdb
Fri Feb 14, 2020 8:47 pm
Forum: General discussion
Topic: What will be likely the next "value node" for the raspberry pi in 2025
Replies: 6
Views: 270

Re: What will be likely the next "value node" for the raspberry pi in 2025

Broadcom makes the silicon, so I would look at what they are selling today... and assume that it is value in 5 years. So do you want to know what ARM cores and IP Broadcom is making today? Broadcom is a fabless semiconductor company. That means they buy fab capacity from a foundry like TSMC or Glob...
by jdb
Fri Feb 14, 2020 8:41 pm
Forum: General discussion
Topic: What will be likely the next "value node" for the raspberry pi in 2025
Replies: 6
Views: 270

Re: What will be likely the next "value node" for the raspberry pi in 2025

I think they just like to throw around the latest shiny new phrase "value node". Well, no Moore's law has run out of road, so the only way you can increase transistor density is by increasing the cost per transistor. It follows that there is a cost per transistor metric that follows a different cur...
by jdb
Thu Feb 06, 2020 1:24 pm
Forum: Troubleshooting
Topic: Pi4 no USB Device working
Replies: 7
Views: 340

Re: Pi4 no USB Device working

My estimation is that your Pi is defective - specifically the VLI chipset. I recommend requesting a warranty replacement from whoever you bought it from.
by jdb
Wed Feb 05, 2020 11:41 pm
Forum: General discussion
Topic: Mechanically weakest components of the Raspberry Pi electronics
Replies: 24
Views: 789

Re: Mechanically weakest components of the Raspberry Pi electronics

Pi 3 B had a ceramic resonator antenna for the 2.4GHz band - several users did report that they had managed to knock them off the board.
by jdb
Wed Feb 05, 2020 5:55 pm
Forum: General discussion
Topic: will the price of a RPI zero change after Brexit
Replies: 15
Views: 931

Re: will the price of a RPI zero change after Brexit

This thread has already veered into politics. Locking.
by jdb
Wed Feb 05, 2020 5:52 pm
Forum: General discussion
Topic: Raspberry Pi Zero - Version 2?
Replies: 63
Views: 2118

Re: Raspberry Pi Zero - Version 2?

Yes, but the 4Gig's of ram in the Model 4 B+ is a real winner... B.T.W... why is there no Model 4 A+ (assuming that would follow the patter of a basic board without NIC and USB block) Because you would get a model that had neither Ethernet nor USB. Well, no USB host ports - but a single OTG port. L...
by jdb
Wed Feb 05, 2020 10:02 am
Forum: Troubleshooting
Topic: Pi4 no USB Device working
Replies: 7
Views: 340

Re: Pi4 no USB Device working

Laire wrote:
Tue Feb 04, 2020 10:00 pm
Hardware Error?
I think so. There's an internal hub in the VLI chipset that should provide USB2.0 functionality on downstream ports - but this isn't getting enumerated at all.

Do any USB3.0 devices work?
by jdb
Mon Feb 03, 2020 9:19 pm
Forum: General discussion
Topic: Circuits in space
Replies: 21
Views: 703

Re: Circuits in space

Before the peanut gallery gets well and truly stuck into this thread and derails it at speed, I asked SebastianB28 what the project name was because one exists already, and is very similar to what he's asking about. Astro-Pi (launched December 2015 (I was 6 miles from the launchpad)) has significant...
by jdb
Mon Feb 03, 2020 5:09 pm
Forum: General discussion
Topic: Circuits in space
Replies: 21
Views: 703

Re: Circuits in space

Hello there.

What's the name of the project (the payload, not your code)?
by jdb
Wed Jan 29, 2020 11:45 am
Forum: General discussion
Topic: Raspberry Pi and PCIE port?
Replies: 11
Views: 733

Re: Raspberry Pi and PCIE port?

The root complex on BCM2711 uses a PCIe gen 2.0 speed link with x1 width, so 5GT/s.
by jdb
Sun Jan 26, 2020 1:13 pm
Forum: General discussion
Topic: Underclocking to unbelievable amounts
Replies: 4
Views: 474

Re: Underclocking to unbelievable amounts

Certain clocks have to run at speed for the chip to work - the Ethernet MAC hardware requires 250/125MHz and the core clock needs to be >~100MHz for display/network to work. Your SDRAM bus will always run at the default configured speed (3200MT/s). In theory there's nothing stopping you underclockin...
by jdb
Wed Jan 22, 2020 11:18 am
Forum: Troubleshooting
Topic: Issues since kernel got updated to 4.19.93
Replies: 159
Views: 9185

Re: Issues since kernel got updated to 4.19.93

On the Nov 18 firmware, an you add force_turbo=1 to config.txt and test?
If that works, then can you replace force_turbo=1 with over_voltage=2?
by jdb
Wed Jan 22, 2020 10:18 am
Forum: Troubleshooting
Topic: Issues since kernel got updated to 4.19.93
Replies: 159
Views: 9185

Re: Issues since kernel got updated to 4.19.93

Can you try rpi-update firmwares to see which is the first "bad" version? Keep the VL805 eeprom image at 0137ad.

Use git hashes from here: https://github.com/Hexxeh/rpi-firmware/commits/master

and do sudo rpi-update <hash> - there's only been 10 or so.
by jdb
Mon Jan 20, 2020 10:01 am
Forum: General discussion
Topic: How bad/good is cooling on the Raspberry pi 4?
Replies: 47
Views: 2338

Re: How bad/good is cooling on the Raspberry pi 4?

I suspect that the OP's question has been more thoroughly answered than would be possible from a random "ebay" comment.
by jdb
Fri Jan 17, 2020 1:25 pm
Forum: Advanced users
Topic: VL805 firmware release 0137ad - fixes for Isochronous streams
Replies: 65
Views: 7642

Re: VL805 firmware release 0137ad - fixes for Isochronous streams

Having updated my eeprom and VL805 using the BETA channel I'm now on this USB firmware. I have a new behaviour exhibiting itself with regard to the power cycling of USB on reboot. I have a Pimoroni Keybow attached that would power cycle itself on reboot and successfully reboot itself as a result, h...
by jdb
Fri Jan 17, 2020 10:58 am
Forum: Advanced users
Topic: VL805 firmware release 0137ad - fixes for Isochronous streams
Replies: 65
Views: 7642

Re: VL805 firmware release 0137ad - fixes for Isochronous streams

Please post the full output of dmesg from a fresh power-on.
by jdb
Fri Jan 17, 2020 10:19 am
Forum: Advanced users
Topic: VL805 firmware release 0137ad - fixes for Isochronous streams
Replies: 65
Views: 7642

Re: VL805 firmware release 0137ad - fixes for Isochronous streams

Define "dodgy".

- Please post the output of dmesg and vcgencmd get_throttled
- Please post a full lsusb -v
- Which version of firmware was the last one that worked correctly?
by jdb
Thu Jan 16, 2020 10:27 pm
Forum: Advanced users
Topic: VL805 firmware release 0137ad - fixes for Isochronous streams
Replies: 65
Views: 7642

Re: VL805 firmware release 0137ad - fixes for Isochronous streams

carldani wrote:
Thu Jan 16, 2020 6:20 pm
jdb wrote:
Thu Jan 16, 2020 10:07 am
This thread is about feedback for the firmware release, not for reverse-engineering efforts of the programming utility.
My apologies. Shall I open a new thread for that?
No. I suggest using the flashrom mailing lists.
by jdb
Thu Jan 16, 2020 5:17 pm
Forum: Troubleshooting
Topic: Raspberry pi 4 get really hot
Replies: 21
Views: 1051

Re: Raspberry pi 4 get really hot

This subject has been covered as recently this week, so to save you searching see: https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=262023 That thread a) doesn't mention a single component getting exceptionally hot b) doesn't help the OP troubleshoot the issue. The capacitor is part of one o...
by jdb
Thu Jan 16, 2020 10:07 am
Forum: Advanced users
Topic: VL805 firmware release 0137ad - fixes for Isochronous streams
Replies: 65
Views: 7642

Re: VL805 firmware release 0137ad - fixes for Isochronous streams

This thread is about feedback for the firmware release, not for reverse-engineering efforts of the programming utility.
by jdb
Wed Jan 15, 2020 2:32 pm
Forum: Advanced users
Topic: Controlling USB Port Power on a Raspberry Pi 4
Replies: 7
Views: 1505

Re: Controlling USB Port Power on a Raspberry Pi 4

Hub control messages are the only way to do it on a Pi 4. Port power is ganged, so it's either all-on or all-off. It's worth noting that all models of Pi with port power control have had ganged power switching.
by jdb
Tue Jan 14, 2020 12:38 pm
Forum: Troubleshooting
Topic: Buster OS Bugs
Replies: 81
Views: 3524

Re: Buster OS Bugs

This thread is going nowhere, so I'm locking it. Useful tip: "apt show <pkgname>" will give you the maintainer/homepage for the application in question, e.g: pi@raspberrypi:~$ apt show x11vnc Package: x11vnc Version: 0.9.13-6 Priority: optional Section: x11 Maintainer: Nikita Yushchenko <yoush@debia...
by jdb
Fri Jan 10, 2020 12:02 am
Forum: General discussion
Topic: PCIe over cable standard. I didn't know that was a thing.
Replies: 22
Views: 1059

Re: PCIe over cable standard. I didn't know that was a thing.

Speaking from experience, PCIe over cabled links Sucks(tm). You need, at the very least, active equalisation at each end of the cable (beyond de-emphasis levels catered for in the PCIe spec). There's an effective maximum length of a PCIe cabled link imposed by the lossy nature of the transmission ch...

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