Messages in this thread | | | Subject | Re: [PATCH v13 7/9] ACPI: Translate the I/O range of non-MMIO devices before scanning | From | John Garry <> | Date | Thu, 15 Feb 2018 11:19:00 +0000 |
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> Nothing apart from only being used by arm64 platforms today, which is > circumstantial. > >> >> I understand you need to find a place to add the: >> >> acpi_indirect_io_scan_init() >> >> to be called from core ACPI code because ACPI can't handle probe >> dependencies in any other way but other than that this patch is >> a Hisilicon ACPI driver - there is nothing generic in it (or at >> least there are no standard bindings to make it so). >> >> Whether a callback from ACPI core code (acpi_scan_init()) to a driver >> specific hook is sane or not that's the question and the only reason >> why you want to add this in drivers/acpi/arm64 rather than, say, >> drivers/bus (as you do for the DT driver). >> >> I do not know Rafael's opinion on the above, I would like to help >> you make forward progress but please understand my concerns, mostly >> on FW side. >> > > I did mention an alternative in my "ping" in v12 patch 7/9 (Feb 1), but > no response to this specific note so I kept on the same path. > > Here's what I then wrote: > "I think another solution - which you may prefer - is to avoid adding > this scan handler (and all this other scan code) and add a check like > acpi_is_serial_bus_slave() [which checks the device parent versus a list > of known indirectIO hosts] to not enumerate these children, and do it > from the LLDD host probe instead (https://lkml.org/lkml/2017/6/16/250)" >
Hi Rafael, Lorenzo,
I can avoid adding the scan handler in acpi_indirectio.c by skipping the child enumeration, like with this change in scan.c:
+static const struct acpi_device_id indirect_io_hosts[] = { + {"HISI0191", 0}, /* HiSilicon LPC host */ + {}, +}; + +static bool acpi_is_indirect_io_slave(struct acpi_device *device) +{ + struct acpi_device *parent = dev->parent; + + if (!parent || acpi_match_device_ids(parent, indirect_io_hosts)) + return false; + + return true; +} + static bool acpi_is_serial_bus_slave(struct acpi_device *device) { struct list_head resource_list; bool is_serial_bus_slave = false;
+ if (acpi_is_indirect_io_slave(device)) + return true; + /* Macs use device properties in lieu of _CRS resources */
This means I can move all this scan code into the LLDD.
What do you think? Please let me know.
John
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