Hi, I do not think this patch alone will work on 4.14. An earlier pair of patches which implements the "marvell,armada-38x-uart" quirk is present on the other kernel versions, but I do see it as far back as 4.14. The following two patches are the ones which add support for that compatible string: b7639b0b15dd serial: 8250_dw: Limit dw8250_tx_wait_empty quirk to armada-38x devices 914eaf935ec7 serial: 8250_dw: Allow TX FIFO to drain before writing to UART_LCR Cheers, Joshua Scott ________________________________________ From: gregkh@xxxxxxxxxxxxxxxxxxx <gregkh@xxxxxxxxxxxxxxxxxxx> Sent: Friday, 5 July 2019 8:59 p.m. To: andrew@xxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx; gregory.clement@xxxxxxxxxxx; Joshua Scott Cc: stable-commits@xxxxxxxxxxxxxxx Subject: Patch "ARM: dts: armada-xp-98dx3236: Switch to armada-38x-uart serial node" has been added to the 4.14-stable tree This is a note to let you know that I've just added the patch titled ARM: dts: armada-xp-98dx3236: Switch to armada-38x-uart serial node to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: arm-dts-armada-xp-98dx3236-switch-to-armada-38x-uart-serial-node.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 80031361747aec92163464f2ee08870fec33bcb0 Mon Sep 17 00:00:00 2001 From: Joshua Scott <joshua.scott@xxxxxxxxxxxxxxxxxxx> Date: Wed, 26 Jun 2019 10:11:08 +1200 Subject: ARM: dts: armada-xp-98dx3236: Switch to armada-38x-uart serial node From: Joshua Scott <joshua.scott@xxxxxxxxxxxxxxxxxxx> commit 80031361747aec92163464f2ee08870fec33bcb0 upstream. Switch to the "marvell,armada-38x-uart" driver variant to empty the UART buffer before writing to the UART_LCR register. Signed-off-by: Joshua Scott <joshua.scott@xxxxxxxxxxxxxxxxxxx> Tested-by: Andrew Lunn <andrew@xxxxxxx> Acked-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxx>. Cc: stable@xxxxxxxxxxxxxxx Fixes: 43e28ba87708 ("ARM: dts: Use armada-370-xp as a base for armada-xp-98dx3236") Signed-off-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/arm/boot/dts/armada-xp-98dx3236.dtsi | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/arch/arm/boot/dts/armada-xp-98dx3236.dtsi +++ b/arch/arm/boot/dts/armada-xp-98dx3236.dtsi @@ -360,3 +360,11 @@ status = "disabled"; }; +&uart0 { + compatible = "marvell,armada-38x-uart"; +}; + +&uart1 { + compatible = "marvell,armada-38x-uart"; +}; + Patches currently in stable-queue which might be from joshua.scott@xxxxxxxxxxxxxxxxxxx are queue-4.14/arm-dts-armada-xp-98dx3236-switch-to-armada-38x-uart-serial-node.patch