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by jdb
Fri Jul 19, 2019 5:41 pm
Forum: General discussion
Topic: USB problem on Pi 4B
Replies: 35
Views: 2011

Re: USB problem on Pi 4B

The error message is actually specified in the xHCI spec, the linux xhci-hcd driver just doesn't handle it. It means "xHC tried to write to the event ring buffer but the event ring buffer was full". The event ring buffer is a proxy for interrupts - if a bunch of stuff happens on USB then the hardwar...
by jdb
Fri Jul 19, 2019 3:02 pm
Forum: Troubleshooting
Topic: "New" booting problem
Replies: 8
Views: 404

Re: "New" booting problem

What are you describing as a switch? There are no switches on the Pi 3B+ board.
by jdb
Fri Jul 19, 2019 1:57 pm
Forum: Troubleshooting
Topic: [SOLVED] Pi4 with USB3 SCSI drive problem
Replies: 5
Views: 332

Re: Pi4 with USB3 SCSI drive problem

The blacklist has no effect because it appears your adapter doesn't support UAS anyway.

Can you change the USB3.0 cable for another one or is it captive? We have seen poor performance with badly shielded cables causing the USB3.0 link to get continually reset.
by jdb
Fri Jul 19, 2019 10:52 am
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 807
Views: 77212

Re: Raspberry Pi 4 Thread - general discussion

The new SD controller is an addition, not a replacement. The Broadcom SDHOST device is now unused as the Arasan SD controller now talks to WiFi. Is it still possible on Pi 4, eg in bare metal or a non-linux OS, to use gpio alt settings to connect sdhost to the sdcard, or is the sdcard now hard-wire...
by jdb
Wed Jul 17, 2019 12:15 pm
Forum: Troubleshooting
Topic: PI 4 causing wifi mouse dongle freeze. Heat-related?
Replies: 6
Views: 375

Re: PI 4 causing wifi mouse dongle freeze. Heat-related?

Do you have anything actually plugged into the USB3.0 ports? In which case, you can definitively prove that it's active USB3.0 signalling causing the interference by plugging the devices into the spare USB2.0 port.
by jdb
Wed Jul 17, 2019 11:06 am
Forum: Troubleshooting
Topic: Pi4 && Aeotec Z-Wave USB Stick Gen5
Replies: 20
Views: 2512

Re: Pi4 && Aeotec Z-Wave USB Stick Gen5

This device has some very non-compliant behaviours. - On initial connect, it pulls D+ to +5V through a strong pull-up. After 20ms, the pull strength drops which results in D+ dropping to about 4.1V. This is a gross violation of the USB electrical spec. - If I plug this device into either the Pi 4 or...
by jdb
Tue Jul 16, 2019 2:33 pm
Forum: Troubleshooting
Topic: STICKY: If you have a Raspberry Pi 4 and are getting bad speeds transferring data to/from USB3.0 SSDs, read this
Replies: 27
Views: 6433

STICKY: If you have a Raspberry Pi 4 and are getting bad speeds transferring data to/from USB3.0 SSDs, read this

We have seen reports of extremely degraded performance when using several types of USB3.0 to SSD adapter or when using native USB3.0 disk drives. This post details why there is a difference in behaviour from models prior to Pi 4 and the recommended workaround. Prior to Pi 4, the USB host controller ...
by jdb
Mon Jul 15, 2019 3:04 pm
Forum: Troubleshooting
Topic: Raspberry Pi 4 RTL-SDR stick not working
Replies: 11
Views: 853

Re: Raspberry Pi 4 RTL-SDR stick not working

The latest rpi-update firmware has a potential fix for this issue. Please test and report back.
by jdb
Sat Jul 13, 2019 11:09 pm
Forum: Troubleshooting
Topic: I can´t boot from usb in pi 4
Replies: 74
Views: 6721

Re: I can´t boot from usb in pi 4

Just don't want to use a uSD card. I want to flash an OS to an USB drive, boot on it directly just out of the box like the pi3b+ without having to do it manually. By the way, the first response from staff was : no progress Last response, about 1.5-2 months delay. That's OK, at least we have a clear...
by jdb
Sat Jul 13, 2019 4:24 pm
Forum: Troubleshooting
Topic: Raspberry Pi 4 B stopped & died suddenly [due to AC adaptor]
Replies: 9
Views: 527

Re: Raspberry Pi 4 B stopped & died suddenly

Good to know the Pi isn't DOA.
mob-i-l wrote:
Sat Jul 13, 2019 4:18 pm
It was only the Raspberry Pi AC ADAPTOR P2219 MODEL: KSA-15E-051300HK (USB-C, MADE IN CAMBODIA) that broke after about 1.5 h updating and surfing and no load except official mouse and keyboard.
That's a bit disappointing. Was the adapter part of the kit?
by jdb
Sat Jul 13, 2019 1:13 pm
Forum: Troubleshooting
Topic: Raspberry Pi 4 RTL-SDR stick not working
Replies: 11
Views: 853

Re: Raspberry Pi 4 RTL-SDR stick not working

It'll probably be in rpi-update firmware early next week. apt packages are getting updated frequently so it shouldn't be too long after that.
by jdb
Sat Jul 13, 2019 9:46 am
Forum: Troubleshooting
Topic: I can´t boot from usb in pi 4
Replies: 74
Views: 6721

Re: I can´t boot from usb in pi 4

Nice to see how some guys don't want to admit there's an issue. For every single customer complaining about the lack and regression of usb boot support OUT OF THE BOX as it is for the previous version, the pi 3b+, you're saying they are a minority, most of people don't care about usb booting blabla...
by jdb
Fri Jul 12, 2019 10:53 pm
Forum: Troubleshooting
Topic: I can´t boot from usb in pi 4
Replies: 74
Views: 6721

Re: I can´t boot from usb in pi 4

The pi3b+ can boot from usb The pi4 can't If that's not a regression, what's a regression then? You're advertising the pi4 as desktop replacement... Using a Micro SD as drive. Just the worst way to run an OS. Easy? Yes. Cheap? Yes Fast? No Reliable? No I bought a Pi4 day one. Now I see another arti...
by jdb
Fri Jul 12, 2019 8:16 pm
Forum: General discussion
Topic: RPi4B GPIO reading speed
Replies: 5
Views: 270

Re: RPi4B GPIO reading speed

From my understanding, the rate at which you can read a GPIO register is less than on previous models, correct?

As a test, can you time how long it takes to spin in a loop and read any register in the GPIO block 100,000 times and compare with a 3B+?
by jdb
Fri Jul 12, 2019 5:39 pm
Forum: HATs and other add-ons
Topic: Pi4 - more SPI - more TV Hats?
Replies: 2
Views: 281

Re: Pi4 - more SPI - more TV Hats?

I'm going to go with "yes" but the HATs won't be directly stackable. The SPI pins used by the HAT need to be redirected to another SPI peripheral. Also, data reads from the HAT EEPROMs will collide so the ID pins need to be disconnected and the devicetree entries manually provided/edited.
by jdb
Fri Jul 12, 2019 2:23 pm
Forum: General discussion
Topic: Pi4 GPIO header disaster
Replies: 26
Views: 1574

Re: Pi4 GPIO header disaster

We're going to need pictures of the connectors and barcodes of every Pi that you've received that exhibits bent pins/bad soldering.
by jdb
Fri Jul 12, 2019 2:00 pm
Forum: General discussion
Topic: Pi4 GPIO header disaster
Replies: 26
Views: 1574

Re: Pi4 GPIO header disaster

There's no way that those joints came out of the solder wave machine like that. At some point in its life, it has seen the pointy end of a soldering iron.
by jdb
Fri Jul 12, 2019 12:55 pm
Forum: General discussion
Topic: Pi4 GPIO header disaster
Replies: 26
Views: 1574

Re: Pi4 GPIO header disaster

Can you post a close up macro shot of the GPIO connector plastic surrounding the pins and the underside of the Pi? Don't upload the image to the forum, use imgur or similar for a full-resolution image.
by jdb
Fri Jul 12, 2019 12:29 pm
Forum: General discussion
Topic: I didn't think the usb c power thing was a big deal...
Replies: 92
Views: 4909

Re: I didn't think the usb c power thing was a big deal...

Many thousands of devices are now in the hands of end-users. If this *were* a widespread issue, why aren't the forums flooded with posts with titles like "I plugged my Pi 4 in and it doesn't turn on - no LEDs or anything"? Either users have suddenly got spectacularly good at googling their problem (...
by jdb
Thu Jul 11, 2019 7:37 pm
Forum: General discussion
Topic: RPi4 - MicroSD card speed classes supported?
Replies: 17
Views: 1535

Re: RPi4 - MicroSD card speed classes supported?

I have some USB3 tiny 32GB Lexar USB sticks I use for booting 3B+. Will they be faster on the Pi4's when USB boot is sorted? Will USB sticks be an alternative to SSD's? Never had a USB3 Pi before. At some point uSD's are more expensive than USB and SSD. If they are not faster you are only paying fo...
by jdb
Thu Jul 11, 2019 5:50 pm
Forum: Advanced users
Topic: Analogue audio redux
Replies: 78
Views: 24464

Re: Analogue audio redux

From my reading of the assembler loop, you are "oversampling" by repeating the input sample used for the quantisation and noise shaping, correct? This is suboptimal as zero-order-hold (what you're doing) does not significantly band-limit the input spectrum. Noise shaping only works effectively if th...
by jdb
Wed Jul 10, 2019 3:47 pm
Forum: Troubleshooting
Topic: Raspberry Pi 4 USB Power Issues? RTL-SDRs
Replies: 15
Views: 2508

Re: Raspberry Pi 4 USB Power Issues? RTL-SDRs

https://github.com/raspberrypi/linux/issues/3060#issuecomment-510107304 The bug has been identified - the VLI chip is doing a bad thing. Dunno how to go about fixing it yet - I need to better understand the mechanisms used in the driver before I can make an informed change to cope with the hardware ...
by jdb
Wed Jul 10, 2019 2:17 pm
Forum: HATs and other add-ons
Topic: PoE hat, Raspberry Pi 4, not able to power off
Replies: 50
Views: 3499

Re: PoE hat, Raspberry Pi 4, not able to power off

OUt of interest, what happens if you add a nontrivial load to the 5V GPIO pin? Can you add a bunch of LEDs/resistors such that you draw ~40-50mA at 5V?
by jdb
Wed Jul 10, 2019 9:40 am
Forum: Advanced users
Topic: Pi4 vs Pi3 Audio Performance
Replies: 9
Views: 1041

Re: Pi4 vs Pi3 Audio Performance

The usual suspects:
- Is audacity generating 16-bit samples and storing as 24-bit?
- Dithering at 16-bit resolution?
- Resampling using a suboptimal filter?

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