arm64: SPCR console not autodetected
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Fix Released
|
High
|
dann frazier | ||
Yakkety |
Fix Released
|
High
|
dann frazier |
Bug Description
[Impact]
ARM servers that boot in ACPI mode will not autodetect their console settings. The SBSA (Server Base System Architecture) spec requires that these settings be specified using the ACPI SPCR table. Support for parsing this table just landed upstream in the 4.9 merge window.
[Test Case]
Boot an ARM system in ACPI mode(I used a Cavium ThunderX CRB1S w/ acpi=force). You'll have no console unless you know and explicitly specify the correct console= parameter on the cmdline.
[Regression Risk]
The changes cleanly cherry-pick from upstream, so we'll have upstream support for any regressions. Though the patches do touch code in arch-indep directories, that code is limited by config options that restrict the functionality to either ARM or OpenFirmware systems:
of/serial: move earlycon early_param handling to serial
- Cleanup of OF-specific code.
ACPI: parse SPCR and enable matching console
- Adds parse_spcr() for all archs, but this function is only called from
arch/arm64 code (next patch).
- Adds an arch-generic call to a stub function only if the OF-specific
earlycon parameter is specified. Further, that stub function just returns
-ENODEV on non-OF systems.
ARM64: ACPI: enable ACPI_SPCR_TABLE
- ARM64-specific code, only built if CONFIG_ACPI=y
serial: pl011: add console matching function
- Driver for ARM AMBA-type serial port - code is only activated if a
console=pl011,* parameter is specified on the cmdline.
CVE References
Changed in linux (Ubuntu): | |
status: | New → In Progress |
assignee: | nobody → dann frazier (dannf) |
importance: | Undecided → High |
Changed in linux (Ubuntu Yakkety): | |
status: | In Progress → Fix Committed |
https:/ /lists. ubuntu. com/archives/ kernel- team/2016- October/ 080236. html