I note the linked report is 32 bit as well. Can you confirm this does NOT occur on a 64 bit machine? Be very careful if you're using a 64 bit machine that it's more likely to not have an EHCI controller. Roughly speaking, EHCI is 2.0-level USB while xHCI is 3.0 (UHCI being 1.0, which requires some additional memory hardware to support 64 bit FWIW). Since the errors relate to EHCI, this is going to be crucial. `lspci | grep HCI` should help out in that regard. It also might be good to check a 32 bit kernel on a 64 bit machine if you can get that test out of the way.
It is possible this may affect other controller architectures, but I doubt it. On the other hand, EHCI can handle 1.0 and 2.0 devices and will likely downgrade a 3.0 device to 2.0 speeds. If it's possible, checking all those different ones will likely prove helping in understanding the scope of the problem. ** Tags removed: cosmic ** Tags added: lubuntu -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1794922 Title: lubuntu 18.10 x86 (32bit) image fails to load "ehci-pci 0000:00:a.7: dma_direct_map_sg: overflow 0x000000016e3f3000+2048 of device mask ffffffff" repeats Status in linux package in Ubuntu: Incomplete Status in linux package in Debian: Unknown Bug description: -- Background -- Testing the x86 (32bit) ISO image on various machines. After zsync download, the thumb-drive is tested ("check disk for defects") & passes; and worked fine on two systems today (dell d610 & hp dx6120), however -- Issue -- dell 755 (desktop) & hp dc7700 (small form factor) it just sits at lubuntu plymouth screen. switching to messages, it's just the following repeating // on dell 755 "ehci-pci 0000:00:1a.7: dma_direct_map_sg: overflow 0x000000016e3f3000+2048 of device mask ffffffff" // on hp dc7700 "ehci-pci 0000:00:1a.7: dma_direct_map_sg: overflow 0x0000000162317000+2048 of device mask ffffffff" NOTE: I can't copy/paste from systems, as it never completes boot; I left it >30mins (on 755) & it just kept repeating message. I've manually typed it; so typo's could have been made. A discussion on #lubuntu-devel provided a possible cause (Thank you Walter!) - --- <wxl> guiverc: lyorian: http://debian.2.n7.nabble.com/Bug-908924-dma-direct-map-sg-overflow-on-USB-access-after-upgrade-to-kernel-4-18-td4387757.html <wxl> seems like it's a usb issue of some kind with 4.18 --- This fits because whilst I do my testing mostly on d610 & t43 (no issues today), I'd tested Lubuntu 18.10 before on the dell 755 with no issues. My last test was also long enough ago to be on 4.17 kernel. I'll add `lshw` files for the two failed systems To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1794922/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
