On Wed, Jul 6, 2016 at 3:34 AM, Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> wrote: > 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]? > Yes, 6/8 and 8/8 both touch Documentation/acpi/ssdt-overlays.txt, but it should be trivial to fix 8/8 if we pull out 6/8. I've send an updated v6 for 6/8 only that fixes the issue Matt and Geert noticed, so maybe its worth waiting for a couple of days for Matt's review. -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
