[PATCH tty v6 0/2] Convert 8250 to NBCON, take 2

From: John Ogness

Date: Mon Jul 20 2026 - 06:34:22 EST


Hi,

This is v6 of a series to convert the 8250 driver to an NBCON
console, providing both threaded and atomic printing
implementations. v5 of this series is here [0].

Note that v5 was pulled into the 6.14 merge window, but was
then reverted before the 6.14-rc1 release due to kernel test
robot problems. It turned out that the problems were related
to general 8250 driver issues. Those issues have now been
addressed mainline, paving the way for a second take at
converting the 8250 driver to NBCON.

This time we have Sashiko, which is sure to provide some
insights that we oversaw with v5.

The changes since v5:

- A new @avoid_modem_status_work field is added to struct
uart_8250_port in order to avoid handling modem control
during the suspend/resume window.

- Handle any pending modem control on resume.

- Allow serial8250_fifo_wait_for_lsr_thre() to be called
with wctxt=NULL since the helper is now used in
dw8250_idle_enter().

John Ogness

[0] https://lore.kernel.org/lkml/20250107212702.169493-1-john.ogness@xxxxxxxxxxxxx

John Ogness (2):
serial: 8250: Switch to nbcon console, take 2
serial: 8250: Revert "drop lockdep annotation from
serial8250_clear_IER()"

drivers/tty/serial/8250/8250.h | 4 +-
drivers/tty/serial/8250/8250_core.c | 44 ++++++-
drivers/tty/serial/8250/8250_dw.c | 2 +-
drivers/tty/serial/8250/8250_port.c | 193 +++++++++++++++++++++++-----
include/linux/serial_8250.h | 16 ++-
5 files changed, 216 insertions(+), 43 deletions(-)


base-commit: 782f4dbd1794b4f30dc116a7ca42c5962c409be8
--
2.47.3