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SubjectRe: [PATCH v5 0/8] ACPI overlays
Date
On Friday, July 01, 2016 11:19:04 PM Octavian Purdila wrote:
> This patch set enables custom ACPI board configuration by adding
> mechanisms in the Linux kernel for loading user defined SSDTs.
>
> In order to support ACPI open-ended hardware configurations we need a
> way to augment the ACPI configuration provided by the firmware
> image. A common example is connecting sensors on I2C / SPI buses on
> development boards.
>
> Although this can be accomplished by creating a kernel platform driver
> or recompiling the firmware image with updated ACPI tables, neither is
> practical: the former proliferates board specific kernel code while
> the latter requires access to firmware tools which are often not
> publicly available.
>
> Because ACPI supports external references in AML code a more practical
> way to augment firmware ACPI configuration is by dynamically loading
> user defined SSDT tables that contain the board specific information.
>
> Currently it is possible to load SSDT overlays using the upgrade
> initrd mechanism introduced in 4.7. This patch series adds support for
> two more methods:
>
> * From an EFI variable
>
> This is the preferred method, when EFI is supported on the platform,
> because it allows a persistent, OS independent way of storing and
> updating the user defined SSDTs. There is also work underway to
> implement EFI support for loading user defined SSDTs and using this
> method will make it easier to convert to the EFI loading mechanism
> when that will arrive.
>
> * From userspace via configfs
>
> This is useful when we want to defer the operation to userspace for
> platform detection, loading the SSDTs from a custom partition, etc.
>
>
> Changes from v4:
>
> * EFI: use ucs2_as_utf8 and memcmp to check if the variable name
> matches the kernel command line parameter; fold the EFI ACPI table
> load code in the iterator function
>
> * I2C/SPI: add more information in the commit logs about how the
> enumeration status is set and checked; also add a new check of the
> enumerated status for the ACPI device remove reconfiguration
> notification
>
> Changes from v3:
>
> * fix a bisectability issue reported by kbuild
>
> * rework the enumeration fix to support PRP0001 enumeration; also,
> introduce acpi_device_set/clear_enumerated() for clarity
>
> * clear the enumerated status for acpi_device when the I2C/SPI clients
> are removed (for example as a result of an adapter removal) to allow
> the devices to be re-enumerated later
>
> Changes from v2:
>
> * fix a few issues caught by the kbuild test robot
>
> * add more configfs table attributes
>
> * removed the initrd based loading functionality from this patch set
> as this can already be accomplished in 4.7 using the ACPI table
> upgrade mechanism
>
> * rebased to 4.7-rc3
>
> Changes from v1:
>
> * rebased on top of the ACPI install from initrd table functionality;
> there is significant overlap between the 1st patch in this series
> and these patch [1] from Lv - I kept it in this series until the
> discussions around the taint and config option are resolved
>
> * make sure EFI_RUNTIME_SERVICES are available before trying to use
> EFI variables to load tables
>
> * rework the ACPI reconfiguration notifications to work on device
> granularity (device added or removed) instead of table granularity
> (table loaded or unloaded)
>
> * add support for table unloading / device removal
>
> * note that the last patch is just a hack to be able to test the table
> unload / device remove functionality, if someone wants to try out
> this patch set
>
> [1] https://patchwork.kernel.org/patch/8795931/
>
> Octavian Purdila (8):
> Documentation: acpi: add SSDT overlays documentation
> acpi: fix enumeration (visited) flags for bus rescans
> acpi: add support for ACPI reconfiguration notifiers
> i2c: add support for ACPI reconfigure notifications
> spi: add support for ACPI reconfigure notifications
> efi: load SSTDs from EFI variables
> acpi: add support for configfs
> acpi: add support for loading SSDTs via configfs
>
> Documentation/ABI/testing/configfs-acpi | 36 +++++
> Documentation/acpi/ssdt-overlays.txt | 172 ++++++++++++++++++++
> Documentation/kernel-parameters.txt | 7 +
> MAINTAINERS | 1 +
> drivers/acpi/Kconfig | 9 ++
> drivers/acpi/Makefile | 1 +
> drivers/acpi/bus.c | 9 ++
> drivers/acpi/configfs.c | 267 ++++++++++++++++++++++++++++++++
> drivers/acpi/internal.h | 3 +
> drivers/acpi/scan.c | 81 +++++++++-
> drivers/acpi/sysfs.c | 6 +-
> drivers/firmware/efi/efi.c | 85 ++++++++++
> drivers/i2c/i2c-core.c | 175 ++++++++++++++++-----
> drivers/spi/spi.c | 100 +++++++++++-
> include/linux/acpi.h | 36 +++++
> 15 files changed, 932 insertions(+), 56 deletions(-)
> create mode 100644 Documentation/ABI/testing/configfs-acpi
> create mode 100644 Documentation/acpi/ssdt-overlays.txt
> create mode 100644 drivers/acpi/configfs.c

It looks like all patches in this series except for the [6/8] are good to go.

Do any of them depend on the [6/8]?

Thanks,
Rafael

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