From: Rafael J. Wysocki Date: Fri, 31 Mar 2017 22:45:52 +0000 (+0200) Subject: ACPI / scan: Prefer devices without _HID for _ADR matching X-Git-Tag: v4.14-rc1~1175^2^2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=fdad4e7a876a2cb3d2c1f04e5418c324e79fffef;p=platform%2Fkernel%2Flinux-rpi3.git 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 Tested-by: Hans de Goede Cc: 4.10+ # 4.10+ Signed-off-by: Rafael J. Wysocki --- diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c index fb19e1c..edc8663 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; }