On Wed, Jan 03, 2018 at 12:12:06PM +0100, Marcin Wojtas wrote: > Hi Graeme, > > 2018-01-03 12:00 GMT+01:00 Graeme Gregory <graeme.gregory@xxxxxxxxxx>: > > On Mon, Dec 18, 2017 at 10:40:31AM +0100, Ard Biesheuvel wrote: > >> On 18 December 2017 at 10:17, Marcin Wojtas <mw@xxxxxxxxxxxx> wrote: > >> > Hi, > >> > > >> > This patchset introduces ACPI support in mvpp2 and mvmdio drivers. > >> > First three patches introduce fwnode helpers for obtaining PHY > >> > information from nodes and also MDIO fwnode API for registering > >> > the bus with its PHY/devices. > >> > > >> > Following patches update code of the mvmdio and mvpp2 drivers > >> > to support ACPI tables handling. The latter is done in 4 steps, > >> > as can be seen in the commits. For the details, please > >> > refer to the commit messages. > >> > > >> > Drivers operation was tested on top of the net-next branch > >> > with both DT and ACPI. Although for compatibility reasons > >> > with older platforms, the mvmdio driver keeps using > >> > of_ MDIO registering, new fwnode_ one proved to fully work > >> > with DT as well (tested on MacchiatoBin board). > >> > > >> > mvpp2/mvmdio driver can work with the ACPI representation, as exposed > >> > on a public branch: > >> > https://github.com/MarvellEmbeddedProcessors/edk2-open-platform/commits/marvell-armada-wip > >> > It was compiled together with the most recent Tianocore EDK2 revision. > >> > Please refer to the firmware build instruction on MacchiatoBin board: > >> > http://wiki.macchiatobin.net/tiki-index.php?page=Build+from+source+-+UEFI+EDK+II > >> > > >> > Above support configures 1G to use its PHY normally. 10G can work now > >> > only with the link interrupt mode. Somehow reading of the > >> > string property in fwnode_mdiobus_child_is_phy works only with > >> > DT and cannot cope with 10G PHY nodes as in: > >> > https://pastebin.com/3JnYpU0A > >> > > >> > Above root cause will be further checked. In the meantime I will > >> > appreciate any comments or remarks for the kernel patches. > >> > > >> > >> Hi Marcin, > >> > >> I have added linux-acpi and Graeme to cc. I think it makes sense to > >> discuss the way you describe the device topology before looking at the > >> patches in more detail. > >> > >> In particular, I would like to request feedback on the use of > >> [redundant] 'reg' properties and the use of _DSD + compatible to > >> describe PHYs. Usually, we try to avoid this, given that it is > >> essentially a ACPI encapsulated DT dialect that is difficult to > >> support in drivers unless they are based on DT to begin with. Also, > >> non-standard _DSD properties require a vendor prefix, it is not > >> freeform. > >> > >> For reference, the ACPI description is here (starting at line 175) > >> https://github.com/MarvellEmbeddedProcessors/edk2-open-platform/blob/72d5ac23b20dd74d479daa5e40ba443264b31261/Platforms/Marvell/Armada/AcpiTables/Armada80x0McBin/Dsdt.asl > >> > > So the representation of PHY's with _DSD was kind of formalised here > > > > http://www.uefi.org/sites/default/files/resources/nic-request-v2.pdf > > > > This is already in use in the kernel, and that DSDT seems to be along the same > > lines. So seems ok in that manner. > > > > The "reg", 0 property seems a little odd, it would probably make more > > sense to check for the lack of ranges passed in in ACPI manner _CRS. > > > > I already agreed with 'reg' being awkward in the later emails. > Wouldn't _ADR be more appropriate to specify PHY address on MDIO bus? > Ah it is an actual address, then yes _ADR is probably more appropriate. Graeme
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