Posted: Tue Mar 14, 2023 6:12 Post subject: Asus RT-AC68U - external USB 3.0 hub flakiness?
My Asus RT-AC68U cannot see any drives connected to a powered USB 3.0 hub via the USB 3.0 port. When the USB 3.0 hub is connected to the USB 2.0 port, all the drives appear. Likewise, with a single drive connected to the USB 3.0 port, all is likewise fine. I have tested by automounting in the GUI or non automounted and looking for the drives via "fdisk -l" or "ls /dev" (in the former, there are no sd* drives shown and the various USB and sd* entries representing the drives are likewise missing with the latter command). The drives simply are not recognized through the system when connected to the USB 3 port and a USB 3.0 hub.
I do not have the most recent couple builds tested, but have tested up to r51617 and r51935 and am currently running DD-WRT v3.0-r51040 std while working through an IPv6 issue on Comcast and DD-WRT. I also used random builds throughout the last 12 months. Same behavior. Merlin firmware has a similar problem but my solution there is to toggle USB 3 support on/off and the drives will show up when connected to the USB 3.0 hub. While I could simply switch back to Merlin, I find DD-WRT to largely function better for me, despite the occasional bug. Any help appreciated. Thank you!
I'm sure if you search in this forum long enough, you will know this and similar bugs are a known issue on devices with two USB ports and has been an issue for a while. The only way to properly address and troubleshoot it is to upgrade to current release (52020), reset to defaults / hard reset and re-configure your router from scratch to see if the issue exists in the current release. Otherwise, issues may not get any attention when reported.
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Posted: Fri Mar 17, 2023 15:36 Post subject: Re: Asus RT-AC68U - external USB 3.0 hub flakiness?
silvarios wrote:
My Asus RT-AC68U cannot see any drives connected to a powered USB 3.0 hub via the USB 3.0 port. When the USB 3.0 hub is connected to the USB 2.0 port, all the drives appear. Likewise, with a single drive connected to the USB 3.0 port, all is likewise fine. I have tested by automounting in the GUI or non automounted and looking for the drives via "fdisk -l" or "ls /dev" (in the former, there are no sd* drives shown and the various USB and sd* entries representing the drives are likewise missing with the latter command). The drives simply are not recognized through the system when connected to the USB 3 port and a USB 3.0 hub.
What if you plugged in the USB drive *BEFORE* turning on the router? If it fixed it, then it's hot-plugging issue.
And the file system of the USB drive? NTFS? FAT32? ext3? _________________ Router: Asus RT-N18U (rev. A1)
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Posted: Tue Mar 21, 2023 17:34 Post subject: Re: Asus RT-AC68U - external USB 3.0 hub flakiness?
mwchang wrote:
What if you plugged in the USB drive *BEFORE* turning on the router? If it fixed it, then it's hot-plugging issue.
And the file system of the USB drive? NTFS? FAT32? ext3?
That's a good question. I only use EXT4 for drives. It does not seem to matter the order of the process. If I leave the drive connected before boot or connect after a full boot, anything connected to the USB 3 hub on a USB 3 port is simply missing.
I was going to simply disable automount and use a mounting script I had if there was an issue, but since the system can't see the drives, that doesn't actually work either. My work around right now is to simply have the hub on the USB 2.0 port and the USB stick with JFFS/OPT on the USB 3.0 port. At least everything shows up that way.
Last edited by silvarios on Tue Mar 21, 2023 17:47; edited 1 time in total
I'm sure if you search in this forum long enough, you will know this and similar bugs are a known issue on devices with two USB ports and has been an issue for a while. The only way to properly address and troubleshoot it is to upgrade to current release (52020), reset to defaults / hard reset and re-configure your router from scratch to see if the issue exists in the current release. Otherwise, issues may not get any attention when reported.
Totally understand this consideration but when I tested every single of the dozen or so builds in the last year, they were recent builds (as in the most recent or second most recent). As you said, it doesn't seem to work.
I think there's something weird about the USB 3 driver perhaps? Like it can't understand a hub on that port? Some kind of conflict with ID or polling or something? The USB 2.0 port seems to work. Literally if I check cat proc/bus/usb/devices there is nothing there when using the hub on USB 3.0. Is there a way to make both ports function as USB 2.0 to test the theory of the driver?
I'd love to upgrade yet again to a newer build than the ones I tried from two weeks back, but I have to pick a time when I can take everything down because I seem to lose proper IPv6 LAN access with DD-WRT builds after a certain point.
The kernel has to probe the hardware, which will affect drive mounting and recognition. The use of external USB hubs is a mixed bag, at best, and dual-USB port devices have always been kind of problematic. _________________ "The woods are lovely, dark and deep,
But I have promises to keep,
And miles to go before I sleep,
And miles to go before I sleep." - Robert Frost
"I am one of the noticeable ones - notice me" - Dale Frances McKenzie Bozzio
The kernel has to probe the hardware, which will affect drive mounting and recognition. The use of external USB hubs is a mixed bag, at best, and dual-USB port devices have always been kind of problematic.
Yes, mixed bag indeed. Thank you for your help.
I did test some more. If I swap out the USB 3 cable (it's a USB 3 micro B) on the hub with a simple USB 2 micro b when connected to the USB 3 port, all the drives likewise show up and even automount fine.
So it's definitely some kind of conflict with probing a USB 3 device that has multiple ports since singular USB 3 drives work fine individually.
And even further testing... if I connect a USB 2.0 drive to the USB 3 hub connected with a USB 3 cable into the USB 3.0 port, that drive will mount, but not any of the USB 3 drives. So again, it seems to be an incompatibility with this router's chipset at least and any USB 3 devices connected to a USB 3 hub. Again, each singular drive will work when directly connected to the USB 3 port on the router.
If anyone has a USB 3 hub and wants to test their own routers running DD-WRT or at least routers with these older Broadcom chipsets, please let me know what you find.
I'd tell you what cat /proc/bus/usb/devices reports with the one drive working and everything else missing... but the command over SSH simply hangs now. So I'll need to figure that out after a reboot. ¯\_ (ツ)_/¯
