There have been quite a few posts on hotspot hangs and other difficulties with ASI cams and USB 3. I think I'm ready to suggest a more general statement about USB 3 and Pi4-4GB failures (i.e. beyond ASI cams). For the last day or so, I've been trying to get a USB 3 120GB SSD and a powered USB 3 Hub added to my config. I am using SM OS, and a Pi4-4GB. Each and every time I plug a USB 3 cable into a USB 3 port (regardless of whether it is for the powered USB Hub, SSD, or ASI cam), I get a hotspot hang. When I unplug and move the 3.0 cable to a 2.0 USB port, it degrades to 2.0 protocol/speed and the hotspot recovers. Any screen that was present before the hang is functional afterwards. The message log clearly shows that the SSD was recognized and mounted, but the hotspot is affected so the config is unworkable. Leaving off the SSD config, I tested all powered Hub connections (ASI cams x2, PPB, and Celestron HC), and they all work with a USB 3 cable plugged into a USB 2 port, but not when using the USB 3 cable in a USB 3 port. Doesn't matter if I try both or only 1, anytime a USB 3 cable is attached to a USB 3 port, the Pi4-4GB system hotspot hangs.

So, am I missing something? Does anyone have a USB 3 cable plugged into USB 3 port on a Pi4-4GB config with a working config?
Jasem, can you comment on upcoming SW release particulars for the hotspot issue? Is this a generalized USB3.0 issue, or just a hotspot issue? Is this SM OS, or Pi4 firmware (or both)?

Addendum: I started looking for Pi4-4GB issues on the Pi sites, and saw this: www.cnx-software.com/2019/11/04/raspberr...ork-on-ubuntu-19-10/
After setting the memory down to 3GB, I was able to get the USB3 cable for the powered HUB working. Still no joy on the SDD though. I read that many adapter cables don't
work well, and I've ordered another brand to try. Will post again with the results once I know better. Odd though that the cable can work in 2.0 just fine.....

Addendum2: Spoke too soon. It's just plain flaky. Sometimes I can get it to work, and other times not. VERY INCONSISTENT. The memory fix doesn't seem to always work. Just going to need to wait for a firmware patch and or give up on the 4GB Pi4 version if it doesn't get fixed soon.....

It's fixed in SM OS v1.5.0 Stable for both RPi3 and RPi4 coming up in a few days. We are now in the final phases of testing, so stay tuned.

I have a working configuration, I have my SM running from a USB 3 SSD Drive, and also have a USB 3 thumb drive plugged into the other port and all works well.. and if I run SM from the SD card then I can still use the USB 3 ports and get a working hotspot.... although I do have my hotspot set to 5GHz only and on channel 44 which does help a lot....

I'm running Astroberry (not Stellarmate) on a Pi4-4GB.

I've moved Astroberry to a 500GB Samsung SSD and it plugs into the USB3.0 port on the Pi. the other USB3.0 connects to a 7 port USB3.0 hub which connects an ASI camera (which also has a USB2.0 hub, which connects the EFW and the ASI Guide camera), additionally the 7 port hub connects the Focuser, Mount, Flats generator, 80mm Case fans and USB GPS.

The only problem I've been having is the awful USB connector from the Pi4 to the 7 port hub, I wish they would use something a bit more robust, seriously thinking about superglue the cable to the port at the hub end.

Not had any issues with SSD, I power my hub from 12V line from PSU and use a 3A 5V USB to car cigarette lighter to power the Pi from a 12V line. Your problem generally sounds like power issues.

@gilesco, Thanks for the reply. Sounds like you've got a "good" Pi4-4GB. Lots of other Pi4-4GB users out there where the USB3 ports are not working so well. Pretty sure my issue isn't power. I have a 10 amp PS split between mount and PPB. PPB 12v DSLR output drives an isolated 5V converter for Pi4. The Pi4 only pulls 0.3-0.4 amps pretty consistently after boot (likely more at boot, but not as much as the PS/PPB can deliver - 10 amps). There's plenty of amps available for a powered hub and connected devices. In various attempts to connect the powered hub and SSD separately, I had only 1 USB 3 port (no USB2 ports) in play. Neither config worked consistently. Multiple different cables were used, although only 1 SSD SATA III adapter was tested. I watched PPB closely for amp draw and voltage drop. No issues seen.

The patch that Jasem suggested is my current hope. I'll reconsider options if the patch doesn't do the trick. Until then, thanks again for the feedback. This will happen, just need to stay with it until I beat the config into submission! p.s. on your hub side USB 3 cable, are you using the new USB3 - B cable design? Seems hard to think it wouldn't be tight enough given the extra "side-car" on the connector....mine is pretty tight!

Hello all

may be or not related to the original hotspot hang description I experienced a complete failure of the USB subsystem on the raspberry Pi 4, 4 GB RAM , raspberry Pi power supply, sometimes after 30 minutes, sometimes several hours after boot:The only way to get the USB devices back was a reboot.

I found two reports [RPi4 4GB] xHCI host controller not responding, assume dead , Issues since kernel got updated to 4.19.93 . Without solving the underlying problem both recommended to increase in /boot/config.txt the value of the parameter

Having done that I rebooted and started INDI/EKOS with an ASI294MC@USB 3.0 and FTDI USB Serial Device@USB 2.0 ports (no powered USB hub). Then I set the camera to 1x1 binning and started a video. Within the last 23 hours the devices remained alive and the command shows:under "full video load" instead of 0.81 ... 0.83V. I let my setup run for a further day but I assume that solved my issue.

Reasonably increasing the CPU voltage does no harm. May be you give it a try.

Kind regards, wildi

Update 2020-02-10: the video stream and hence the USB devices are still alive.

The hub uses the USB3 micro-B cable design, which is an awful design and has in the past been disconnected by cable snags during slewing. I am considering glueing it, but for the time being I have contained everything in a wooden box and velcro'd everything to avoid any movement.

@gilesco: Maybe a smaller USB hub with a true USB 3 B connector might be less of a head ache. I have this (for comparison): www.amazon.com/gp/product/B00SIQIV04, and this cable: www.amazon.com/gp/product/B07QBG249T. The powered hub is small! Only 3.5 x 2.25 x 1.25 inches with 7 ports (5 on one side, and two on the other). It sits nicely on the OTA rail, where I have the Pi4, PPB, and SSD in a stack. Anyway, just an idea to eliminate the headache of the micro-B... Cheers, Doug

@Wildi: I tried your suggestion, and FYI, it didn't help with the USB hotspot problem. It DID raise the voltage to the core though, and I think this might have benefits as you suggest. So thanks for the suggestion. While looking at web references, I saw the Pi4 can have it's arm_freq safely raised a bit too. The parameter for config.txt is arm_freq=1750. After reboot I get the same voltage as you reported (0.91-0.94) and the added arm frequency boost. Hard to tell precisely, but it appears the cost is only 1-2 degrees C on the core. I'm running cool anyway @42C in daytime, because I have a heat sync and fan. Nighttime should be even better.

An update on my USB3 Pi4-4GB config after SM 1.5 upgrade. I really like this new release, but I'm still having negative USB3/network interaction that I'd like to solve. I can use a Pi4 USB3 port, but only AFTER booting the Pi4 without a connected USB3 cable. A USB3 powered hub is brought up stable before the Pi4 is booted. Here's the odd part: After USB3 hub is up, and after Pi4 is booted, I must FIRST connect the hub's USB3 cable to a Pi4 USB2 port! I can then almost immediately move the USB3 cable from the USB2 port to a USB3 port and keep a stable infrastructure network working indefinitely. Very odd, but very consistent. If I try to boot with a USB3 cable connected to a USB3 port, I almost immediately lock up the infrastructure network VNC session, fail back to hotspot mode, and can't recover the infrastructure network until I remove the USB3 cable AND reboot the Pi4 after the Pi4 returns to the hotspot network (reboot via hotspot VNC session). After the reboot, the infrastructure network returns normal again. Rinse and repeat. UGG.

I've found a few complaints in the Raspberry forum related to Pi4 USB3 and 2.4Ghz wifi interference. As a test, I wrapped my USB3 cable in tinfoil. No difference. I have an isolated 3amp Pi4 PS. I power the USB3 hub from a 10amp PS via PPB before booting the Pi4. I've removed a USB3 SSD out of the config for now. It mounts, but will also freeze the infrastructure network either immediately, or within 30 seconds of mounting. I've got only one USB3 cable (from the powered hub) connected to the Pi4. Everything else is in the powered USB3 hub. Plenty of power to the hub. The cable from Pi4 to hub is a USB3 B to A cable. I'm not quite convinced that USB3 is stable on Pi4. The need to first connect to USB2, then move to USB3 is a strong hint....but of what? If the issue is power related, it's hard to imagine (PPB shows good voltage and low current draw). FWIW, the SSD hangs the network regardless of whether it's plugged into the powered hub or directly from the Pi4's USB3 port. So, it's out for now while I try to understand what's going on with the USB3 hub/Pi4 cable.

While I have a startup strategy that can be infrastructure network stable, it's definitely not ideal. I'd like to be able to boot and have access to the infrastructure network without having to move cables. I'd also like to use my SSD. I'm running out of ideas. Comments?

I've used my USB 3 ASI533MC camera and a USB3 hub without any issues on RPi4. I've connected the USB 2 devices directly to the RPi4, to the ASI camera ports and to the hub. I've disconnected them completely and plugged them back in, never a problem except for the AVX cable connecting to a USB / Serial Prolithic adapter, unplugging it requires a reboot to get it going again.

No issues here with SM OS 1.5.1 and USB3. I've connected two USB 3 cameras at the same time and connected to SM over hotspot.. no networking issue or performance degradation.