False positive ACPI _PRS error messages

[Alex Hung]

New platforms have hardware registers for routing table implemented as "write once". Once set by UEFI firmware during POST, OS will not be able to modify the routing table, and ACPI _PRS method are removed according to ACPI spec.

As a result, generating the error messages "ACPI Exception: AE_NOT_FOUND, Evaluating _PRS" in kernel by default does not make sense, and they should be muted by default.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1773295

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Brad Figg (brad-figg)]

This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-bionic' to 'verification-done-bionic'. If the problem still exists, change the tag 'verification-needed-bionic' to 'verification-failed-bionic'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 4.15.0-24.26

---------------
linux (4.15.0-24.26) bionic; urgency=medium

  * linux: 4.15.0-24.26 -proposed tracker (LP: #1776338)

  * Bionic update: upstream stable patchset 2018-06-06 (LP: #1775483)
    - drm: bridge: dw-hdmi: Fix overflow workaround for Amlogic Meson GX SoCs
    - i40e: Fix attach VF to VM issue
    - tpm: cmd_ready command can be issued only after granting locality
    - tpm: tpm-interface: fix tpm_transmit/_cmd kdoc
    - tpm: add retry logic
    - Revert "ath10k: send (re)assoc peer command when NSS changed"
    - bonding: do not set slave_dev npinfo before slave_enable_netpoll in
      bond_enslave
    - ipv6: add RTA_TABLE and RTA_PREFSRC to rtm_ipv6_policy
    - ipv6: sr: fix NULL pointer dereference in seg6_do_srh_encap()- v4 pkts
    - KEYS: DNS: limit the length of option strings
    - l2tp: check sockaddr length in pppol2tp_connect()
    - net: validate attribute sizes in neigh_dump_table()
    - llc: delete timers synchronously in llc_sk_free()
    - tcp: don't read out-of-bounds opsize
    - net: af_packet: fix race in PACKET_{R|T}X_RING
    - tcp: md5: reject TCP_MD5SIG or TCP_MD5SIG_EXT on established sockets
    - net: fix deadlock while clearing neighbor proxy table
    - team: avoid adding twice the same option to the event list
    - net/smc: fix shutdown in state SMC_LISTEN
    - team: fix netconsole setup over team
    - packet: fix bitfield update race
    - tipc: add policy for TIPC_NLA_NET_ADDR
    - pppoe: check sockaddr length in pppoe_connect()
    - vlan: Fix reading memory beyond skb->tail in skb_vlan_tagged_multi
    - amd-xgbe: Add pre/post auto-negotiation phy hooks
    - sctp: do not check port in sctp_inet6_cmp_addr
    - amd-xgbe: Improve KR auto-negotiation and training
    - strparser: Do not call mod_delayed_work with a timeout of LONG_MAX
    - amd-xgbe: Only use the SFP supported transceiver signals
    - strparser: Fix incorrect strp->need_bytes value.
    - net: sched: ife: signal not finding metaid
    - tcp: clear tp->packets_out when purging write queue
    - net: sched: ife: handle malformed tlv length
    - net: sched: ife: check on metadata length
    - llc: hold llc_sap before release_sock()
    - llc: fix NULL pointer deref for SOCK_ZAPPED
    - net: ethernet: ti: cpsw: fix tx vlan priority mapping
    - virtio_net: split out ctrl buffer
    - virtio_net: fix adding vids on big-endian
    - KVM: s390: force bp isolation for VSIE
    - s390: correct module section names for expoline code revert
    - microblaze: Setup dependencies for ASM optimized lib functions
    - commoncap: Handle memory allocation failure.
    - scsi: mptsas: Disable WRITE SAME
    - cdrom: information leak in cdrom_ioctl_media_changed()
    - m68k/mac: Don't remap SWIM MMIO region
    - block/swim: Check drive type
    - block/swim: Don't log an error message for an invalid ioctl
    - block/swim: Remove extra put_disk() call from error path
    - block/swim: Rename macros to avoid inconsistent inverted logic
    - block/swim: Select appropriate drive on device open
    - block/swim: Fix array bounds check
    - block/swim: Fix IO error at end of medium
    -...