I have the same issue. At the login screen, I select my user, enter the password, the mouse works fine at this point. Click on login, wait, screen comes up.... then at random, the mouse either works fine (about 1 time in 5) or it goes really really slow (4 times out of 5).
Only way I'm working around it is to reboot (usually 5 times ish) till it decides to work. As a test manager by trade I would say this is a P3 at least not a P4, as it's definitely a functional issue not cosmetic, albeit with an untidy workaround (many reboots). I'm running 4.15.0-52-lowlatency #56-Ubuntu SMP PREEMPT Tue Jun 4 23:39:39 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux I'll post contents of lshw and lspci, let me know if you need more. ** Attachment added: "lshw_and_lspci.txt" https://bugs.launchpad.net/ubuntustudio/+bug/1787857/+attachment/5272856/+files/lshw_and_lspci.txt -- 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/1787857 Title: USB mouse cursor lags after random time of correct behaviour Status in Ubuntu Studio: Incomplete Status in linux package in Ubuntu: Confirmed Status in rtirq package in Ubuntu: Confirmed Bug description: I installed Ubuntu Studio 18.04.1 LTS. After the first apt-get update I noticed the following behaviour: after havig logged in, my USB mouse works normally for about ten seconds, then the cursor starts lagging a lot which makes the mouse pretty much unusable. The last dmesg always contain lines these: (more in attached file) [<000000009e659b0c>] irq_default_primary_handler threaded [<00000000fa56edac>] usb_hcd_irq [<000000009e659b0c>] irq_default_primary_handler threaded [<00000000fe1afb05>] _rtl_pci_interrupt [rtl_pci] Disabling IRQ #18 Out of frustration & curiosity I disabled most autostart apps (Settings > Session ... > Autostart) and re-enabled them after rebooting. Since then I rarely encounter the lagging cursor. If I open Settings > Mouse & Touchpad and toggle any option on/off the cursor starts lagging. How can make the cursor work reliably? Some comment in dmesg mentions "irqpoll" boot option Ubuntu Studio 18.04.1 4.15.0-20-lowlatency #21-Ubuntu SMP PREEMPT To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntustudio/+bug/1787857/+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