Re: [PATCH v6 1/9] dax/hmem: Request cxl_acpi and cxl_pci before walking Soft Reserved ranges

Alison Schofield
2026-02-19T03:23:00Z

On Tue, Feb 10, 2026 at 06:44:53AM +0000, Smita Koralahalli wrote:
> From: Dan Williams <dan.j.williams@intel.com>
>
> Ensure cxl_acpi has published CXL Window resources before HMEM walks Soft
> Reserved ranges.
>
> Replace MODULE_SOFTDEP("pre: cxl_acpi") with an explicit, synchronous
> request_module("cxl_acpi"). MODULE_SOFTDEP() only guarantees eventual
> loading, it does not enforce that the dependency has finished init
> before the current module runs. This can cause HMEM to start before
> cxl_acpi has populated the resource tree, breaking detection of overlaps
> between Soft Reserved and CXL Windows.
>
> Also, request cxl_pci before HMEM walks Soft Reserved ranges. Unlike
> cxl_acpi, cxl_pci attach is asynchronous and creates dependent devices
> that trigger further module loads. Asynchronous probe flushing
> (wait_for_device_probe()) is added later in the series in a deferred
> context before HMEM makes ownership decisions for Soft Reserved ranges.
>
> Add an additional explicit Kconfig ordering so that CXL_ACPI and CXL_PCI
> must be initialized before DEV_DAX_HMEM. This prevents HMEM from consuming
> Soft Reserved ranges before CXL drivers have had a chance to claim them.

Reviewed-by: Alison Schofield <alison.schofield@intel.com>

snip