Re: [PATCH 00/11] of: dma-ranges fixes and improvements

From: Robin Murphy
Date: Mon Sep 30 2019 - 08:52:15 EST


On 30/09/2019 13:40, Marek Vasut wrote:
On 9/27/19 2:24 AM, Rob Herring wrote:
This series fixes several issues related to 'dma-ranges'. Primarily,
'dma-ranges' in a PCI bridge node does correctly set dma masks for PCI
devices not described in the DT. A common case needing dma-ranges is a
32-bit PCIe bridge on a 64-bit system. This affects several platforms
including Broadcom, NXP, Renesas, and Arm Juno. There's been several
attempts to fix these issues, most recently earlier this week[1].

In the process, I found several bugs in the address translation. It
appears that things have happened to work as various DTs happen to use
1:1 addresses.

First 3 patches are just some clean-up. The 4th patch adds a unittest
exhibiting the issues. Patches 5-9 rework how of_dma_configure() works
making it work on either a struct device child node or a struct
device_node parent node so that it works on bus leaf nodes like PCI
bridges. Patches 10 and 11 fix 2 issues with address translation for
dma-ranges.

My testing on this has been with QEMU virt machine hacked up to set PCI
dma-ranges and the unittest. Nicolas reports this series resolves the
issues on Rpi4 and NXP Layerscape platforms.

With the following patches applied:
https://patchwork.ozlabs.org/patch/1144870/
https://patchwork.ozlabs.org/patch/1144871/

Can you try it without those additional patches? This series aims to make the parsing work properly generically, such that we shouldn't need to add an additional PCI-specific version of almost the same code.

Robin.