From: "Rafael J. Wysocki" <[email protected]>

If acpi_dev_get_resources() returns overlapping I/O or memory resources,
the subsequent registration of a platform devices will fail with -EBUSY
due to a resource conflict.  This is reported to happen on Acer Aspire
ES1-572 [1].

Avoid that by adjusting resources returned by acpi_dev_get_resources()
to eliminate partial overlaps between them.

This has not been regarded as necessary before because putting
overlapping resources into the _CRS of one device is really pointless,
but now that the issue has been reported to actually happen in the
field, it needs to be done.

Fixes: 8e345c991c8c ("ACPI: Centralized processing of ACPI device resources")
Fixes: 48fe2cddc85c ("tpm_crb: Convert ACPI driver to a platform one")
Reported-by: Julien <[email protected]>
Tested-by: Julien <[email protected]>
Closes: 
https://lore.kernel.org/linux-integrity/cajogg3z6ljpdsdpnbxajgy8_wqxfhybrxe4eiurzf3kpu5a...@mail.gmail.com/
 [1]
Cc: All applicable <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
---
 drivers/acpi/acpi_platform.c |   39 +++++++++++++++++++++++++++++++++++++--
 1 file changed, 37 insertions(+), 2 deletions(-)

--- a/drivers/acpi/acpi_platform.c
+++ b/drivers/acpi/acpi_platform.c
@@ -71,6 +71,39 @@ static struct notifier_block acpi_platfo
        .notifier_call = acpi_platform_device_remove_notify,
 };
 
+static void acpi_platform_adjust_resource(struct acpi_device *adev,
+                                         struct resource *new_res,
+                                         const struct resource *resources,
+                                         unsigned int count)
+{
+       unsigned int i;
+
+       if (!(new_res->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
+               return;
+
+       for (i = 0; i < count; i++) {
+               const struct resource *res = &resources[i];
+
+               if (resource_type(new_res) != resource_type(res))
+                       continue;
+
+               if (!resource_overlaps(new_res, res))
+                       continue;
+
+               dev_info(&adev->dev, "Adjusting %pR for %pR\n", new_res, res);
+               /*
+                * Extend the new resource to include the one that has been
+                * processed already to avoid resource insertion failures during
+                * platform device registration.
+                */
+               if (res->start < new_res->start)
+                       new_res->start = res->start;
+
+               if (res->end > new_res->end)
+                       new_res->end = res->end;
+       }
+}
+
 static void acpi_platform_fill_resource(struct acpi_device *adev,
        const struct resource *src, struct resource *dest)
 {
@@ -151,10 +184,12 @@ struct platform_device *acpi_create_plat
                                return ERR_PTR(-ENOMEM);
                        }
                        count = 0;
-                       list_for_each_entry(rentry, &resource_list, node)
+                       list_for_each_entry(rentry, &resource_list, node) {
+                               acpi_platform_adjust_resource(adev, rentry->res,
+                                                             resources, count);
                                acpi_platform_fill_resource(adev, rentry->res,
                                                            
&resources[count++]);
-
+                       }
                        acpi_dev_free_resource_list(&resource_list);
                }
        }




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