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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2017-04-01 01:45:52 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2017-04-01 01:55:22 +0300
commitfdad4e7a876a2cb3d2c1f04e5418c324e79fffef (patch)
treef3f98b0dc7c36b056c16a7378860d922db47af97 /drivers/acpi/glue.c
parentc02ed2e75ef4c74e41e421acb4ef1494671585e8 (diff)
downloadlinux-fdad4e7a876a2cb3d2c1f04e5418c324e79fffef.tar.xz
ACPI / scan: Prefer devices without _HID for _ADR matching
Commit c2a6bbaf0c5f (ACPI / scan: Prefer devices without _HID/_CID for _ADR matching) added a list_empty(&adev->pnp.ids) check to find_child_checks() so as to catch situations in which the ACPI core attempts to decode _ADR for a device having a _HID too which is strictly against the spec. However, it overlooked the fact that the adev->pnp.ids list for the devices taken into account by find_child_checks() may contain device IDs set internally by the kernel, like "LNXVIDEO" (thanks to Zhang Rui for that realization), and it broke the enumeration of those devices as a result. To unbreak it, replace the overly coarse grained list_empty() check with a much more precise check against the pnp.type.platform_id flag which is only set for devices having a _HID (that's how it should be done from the start, as having both _ADR and _CID is actually permitted). Fixes: c2a6bbaf0c5f (ACPI / scan: Prefer devices without _HID/_CID for _ADR matching) Link: https://bugzilla.kernel.org/show_bug.cgi?id=194889 Reported-and-tested-by: Mike <mike@mikewilson.me.uk> Tested-by: Hans de Goede <hdegoede@redhat.com> Cc: 4.10+ <stable@vger.kernel.org> # 4.10+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/glue.c')
-rw-r--r--drivers/acpi/glue.c12
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
index fb19e1cdb641..edc8663b5db3 100644
--- a/drivers/acpi/glue.c
+++ b/drivers/acpi/glue.c
@@ -99,13 +99,13 @@ static int find_child_checks(struct acpi_device *adev, bool check_children)
return -ENODEV;
/*
- * If the device has a _HID (or _CID) returning a valid ACPI/PNP
- * device ID, it is better to make it look less attractive here, so that
- * the other device with the same _ADR value (that may not have a valid
- * device ID) can be matched going forward. [This means a second spec
- * violation in a row, so whatever we do here is best effort anyway.]
+ * If the device has a _HID returning a valid ACPI/PNP device ID, it is
+ * better to make it look less attractive here, so that the other device
+ * with the same _ADR value (that may not have a valid device ID) can be
+ * matched going forward. [This means a second spec violation in a row,
+ * so whatever we do here is best effort anyway.]
*/
- return sta_present && list_empty(&adev->pnp.ids) ?
+ return sta_present && !adev->pnp.type.platform_id ?
FIND_CHILD_MAX_SCORE : FIND_CHILD_MIN_SCORE;
}