Ubuntu 21.04 (Hirsute Hippo) has reached end of life, so this bug will not be fixed for that specific release.
** Changed in: linux (Ubuntu Hirsute) Status: Confirmed => Won't Fix -- 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/1929452 Title: upstream stable would break ubuntu/xr-usb-serial (deprecated ASYNC flags) Status in linux package in Ubuntu: Confirmed Status in linux source package in Bionic: Confirmed Status in linux source package in Focal: Confirmed Status in linux source package in Groovy: Confirmed Status in linux source package in Hirsute: Won't Fix Status in linux source package in Impish: Won't Fix Bug description: The Ubuntu kernel has carried an out-of-tree driver "ubuntu/xr-usb- serial/" since forever. That driver uses the #define'd constant ASYNCB_INITIALIZED in multiple places, e.g.: if (test_bit(ASYNCB_INITIALIZED, &xr_usb_serial->port.flags)) But this recent mainline commit (and all linux-stable's >= 4.14) removes the definition of ASYNCB_INITIALIZED ... [mainline] d09845e98a05 tty: actually undefine superseded ASYNC flags Some kernel-internal ASYNC flags have been superseded by tty-port flags and should no longer be used by kernel drivers. Fix the misspelled "__KERNEL__" compile guards which failed their sole purpose to break out-of-tree drivers that have not yet been updated. ... Which would make ubuntu/xr-usb-serial/ fail to build (as the upstream commit intends). To avoid that breakage, the stable backports of [mainline] d09845e98a05 will be omitted from all Ubuntu kernels, pending some other resolution of the problem with ubuntu/xr-usb-serial. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1929452/+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