Messages in this thread | | | Date | Wed, 2 Mar 2022 14:15:15 +0100 | From | Marek Behún <> | Subject | Re: [PATCH] arm64: dts: marvell: armada-37xx: Remap IO space to bus address 0x0 |
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On Wed, 2 Mar 2022 14:06:01 +0100 Andrew Lunn <andrew@lunn.ch> wrote:
> On Tue, Mar 01, 2022 at 10:25:39AM +0100, Pali Rohár wrote: > > On Monday 28 February 2022 17:42:03 Gregory CLEMENT wrote: > > > > Hello Pali, > > > > > > > >> Remap PCI I/O space to the bus address 0x0 in the Armada 37xx > > > >> device-tree in order to support legacy I/O port based cards which have > > > >> hardcoded I/O ports in low address space. > > > >> > > > >> Some legacy PCI I/O based cards do not support 32-bit I/O addressing. > > > >> > > > >> Since commit 64f160e19e92 ("PCI: aardvark: Configure PCIe resources from > > > >> 'ranges' DT property") this driver can work with I/O windows which > > > >> have > > > > > > > > Should we add a "Fixes: 64f160e19e92 ("PCI: aardvark: Configure PCIe > > > > resources from 'ranges' DT property")" tag ? > > > > > > Waiting for your confirmation I tried to applied it but it failed. > > > > > > Did you base this patch on v5.17-rc1 ? > > > > > > Gregory > > > > Hello! This change is breaking booting of Turris Mox kernel with older > > bootloader due to bugs in bootloader. > > Do you know what actually goes wrong? > > I've not been involved in the discussion, but looking at the comments > above, not changing the space can result in non-working cards. So it > does sound like something which in general we want to do. Does the > current code assume the bootloader has initialized some registers with > specific values? Can that be moved into the driver so it also works > with older bootloaders?
No. TF-A may remap CPU PCIe window, and so U-Boot fixes these addresses in device-tree. But the fixup function was at first written in such a way that it assumes that the ranges propreties contains specific values. The proposed DT change, together with the fixup function in older U-Boot, will break ranges property to non-functional state.
See corresponding U-Boot patches
https://patchwork.ozlabs.org/project/uboot/patch/20200408172522.18941-5-marek.behun@nic.cz/ https://patchwork.ozlabs.org/project/uboot/patch/20210526155940.26141-5-pali@kernel.org/ https://patchwork.ozlabs.org/project/uboot/patch/20220223125232.7974-1-kabel@kernel.org/
The last patch is not merged yet.
Marek
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