On Thu, Dec 01, 2022 at 10:54:08AM +0200, Ilpo Järvinen wrote: > [ Upstream commit 76bad3f88750f8cc465c489e6846249e0bc3d8f5 ] > > lpuart_global_reset() shouldn't break the on-going transmit engine, need > to recover the on-going data transfer after reset. > > This can help earlycon here, since commit 60f361722ad2 ("serial: > fsl_lpuart: Reset prior to registration") moved lpuart_global_reset() > before uart_add_one_port(), earlycon is writing during global reset, > as global reset will disable the TX and clear the baud rate register, > which caused the earlycon cannot work any more after reset, needs to > restore the baud rate and re-enable the transmitter to recover the > earlycon write. > > Also move the lpuart_global_reset() down, then we can reuse the > lpuart32_tx_empty() without declaration. > > Fixes: bd5305dcabbc ("tty: serial: fsl_lpuart: do software reset for imx7ulp and imx8qxp") > Signed-off-by: Sherry Sun <sherry.sun@xxxxxxx> > Link: https://lore.kernel.org/r/20221024085844.22786-1-sherry.sun@xxxxxxx > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> > --- > > Hi stable folks, > > These two stable-deps seem to be pulled into stable only due to diff > context: > > 07481f448b63 ("serial: fsl_lpuart: Fill in rs485_supported") > 8925c31c1ac2 ("serial: Add rs485_supported to uart_port") > > I think those two should be dropped from the stable queue and the queued > fix for 76bad3f88750 ("tty: serial: fsl_lpuart: don't break the on-going > transfer when global reset") replaced with this backport. As the above are already applied, can you send a fix-up patch to resolve the problems in the backport that you found? thanks, greg k-h