https://bugzilla.kernel.org/show_bug.cgi?id=199035 Bug ID: 199035 Summary: BCM2046B1 and hid2hci generates highcpu usage due to udev since 4.14 kernel Product: Drivers Version: 2.5 Kernel Version: 4.14 4.15 Hardware: All OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: Bluetooth Assignee: linux-bluetooth@xxxxxxxxxxxxxxx Reporter: mathieutournier@xxxxxxxxx Regression: No Created attachment 274593 --> https://bugzilla.kernel.org/attachment.cgi?id=274593&action=edit dmesg Hi, I'm currently running ubuntu 18.04 with a 4.15 kernel and i can observe very high cpu usage to the systemd-udevd deamon. removing the rule : ATTR{bInterfaceClass}=="03", ATTR{bInterfaceSubClass}=="01", ATTR{bInterfaceProtocol}=="02", \ ATTRS{bDeviceClass}=="00", ATTRS{idVendor}=="413c", ATTRS{bmAttributes}=="e0", \ RUN+="hid2hci --method=dell --devpath=%p", ENV{HID2HCI_SWITCH}="1" Solved the high CPU usage eventhough my bluetooth card is not available anymore (as not in hci mode) It seems that the command hid2hci creates a bind/unbind loop in udev that is looping trying to set the device in hci mode. (that what udevadm monitor seems to show, looping from bind to unbind for the device) I suspect a0085f2510e8976614ad8f766b209448b385492f introduced a regression (i have not tried to revert it yet). Please not that there also seem to be a bug in hid2hci.c from bluez l148 : if (err == 0) { err = -1; errno = EALREADY; } Correcting this and recompile bluez desn't solve the issue as cpu usage remains very high. Using a 4.13 kernel result in a normal CPU usage, this seems a regression in 4.14. Other people seems to have the same issue, here is a bug report related to this : https://dev.solus-project.com/T5224 Thanks a lot for your support, Mathieu Tournier -- You are receiving this mail because: You are the assignee for the bug.-- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html