Re: [PATCH 02/11] dt-bindings: serial: snps-dw-apb-uart: Relax dma-names order constraint

From: Cristian Ciocaltea
Date: Fri Mar 17 2023 - 06:22:03 EST


On 3/17/23 10:31, Krzysztof Kozlowski wrote:
On 15/03/2023 12:47, Cristian Ciocaltea wrote:
Commit 370f696e4474 ("dt-bindings: serial: snps-dw-apb-uart: add dma &
dma-names properties") documented dma-names property to handle Allwiner
D1 dtbs_check warnings, but relies on a strict rx->tx ordering, which is
the reverse of what a different board expects:

rk3326-odroid-go2.dtb: serial@ff030000: dma-names:0: 'rx' was expected

A quick and incomplete check shows the inconsistency is present in many
other DT files:

Why not fixing the DTS? The properties should have fixed order.

I was initially concerned about the risk of a potential ABI breakage, but I think that's not really a problem since dma-names is not directly accessed in the driver and DT Kernel API doesn't rely on a particular order.

If there are no objections, I would switch the order in the binding to tx->rx, since that's what most of the DTS use, and fix the remaining ones.

Best regards,
Krzysztof

Thanks,
Cristian