acpi/nfit: Require opt-in for read-only label configurations (0171b6b7) · Commits · e / devices / android_kernel_fairphone_FP5

Recent fixes to command handling enabled Linux to read label configurations that it could not before. Unfortunately that means that configurations that were operating in label-less mode will be broken as the kernel ignores the existing namespace configuration and tries to honor the new found labels. Fortunately this seems limited to a case where Linux can quirk the behavior and maintain the existing label-less semantics by default. When the platform does not emit an _LSW method, disable all label access methods. Provide a 'force_labels' module parameter to allow read-only label operation. Fixes: ("acpi/nfit: Fix command-supported detection") Reported-by:

Dexuan Cui <decui@microsoft.com> Reviewed-by:

Dexuan Cui <decui@microsoft.com> Signed-off-by:

Dan Williams <dan.j.williams@intel.com>

drivers/acpi/nfit/core.c

+17 −0

Original line number	Diff line number	Diff line
		@@ -56,6 +56,10 @@ static bool no_init_ars;
		module_param(no_init_ars, bool, 0644);
		MODULE_PARM_DESC(no_init_ars, "Skip ARS run at nfit init time");

		static bool force_labels;
		module_param(force_labels, bool, 0444);
		MODULE_PARM_DESC(force_labels, "Opt-in to labels despite missing methods");

		LIST_HEAD(acpi_descs);
		DEFINE_MUTEX(acpi_desc_lock);

		@@ -1916,6 +1920,19 @@ static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc,
		dev_dbg(dev, "%s: has _LSW\n", dev_name(&adev_dimm->dev));
		set_bit(NFIT_MEM_LSW, &nfit_mem->flags);
		}

		/*
		* Quirk read-only label configurations to preserve
		* access to label-less namespaces by default.
		*/
		if (!test_bit(NFIT_MEM_LSW, &nfit_mem->flags)
		&& !force_labels) {
		dev_dbg(dev, "%s: No _LSW, disable labels\n",
		dev_name(&adev_dimm->dev));
		clear_bit(NFIT_MEM_LSR, &nfit_mem->flags);
		} else
		dev_dbg(dev, "%s: Force enable labels\n",
		dev_name(&adev_dimm->dev));
		}

		populate_shutdown_status(nfit_mem);