XPS 9510 (TGL) Screen Brightness could not be changed

[AceLan Kao]

[Impact]
Dell XPS 15 9510(TGL) uses DPCD to control backlight, and need to add this panel to edid_quirk.

kernel: [ 1.719773] i915 0000:00:02.0: [drm] Panel advertises DPCD backlight support, but VBT disagrees. If your backlight controls don't work try booting with i915.enable_dpcd_backlight=1. If your machine needs this, please file a _new_ bug report on drm/i915, see https://gitlab.freedesktop.org/drm/intel/-/wikis/How-to-file-i915-bugs for details.

Kernel 5.12+ support the backlight via:
commit: <4a8d79901d5b> ("drm/i915/dp: Enable Intel's HDR backlight interface (only SDR for now)"), and doesn't need this quirk.

[Fix]
Adding the panel's MFG to edid_quirk makes system switch to use DPCD to control backlight.

[Test]
Verified on Dell XPS 9510(TGL)

[Where problems could occur]
The quirk is for a dedicate panel, and won't affect other platforms.

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

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-focal' to 'verification-done-focal'. If the problem still exists, change the tag 'verification-needed-focal' to 'verification-failed-focal'.

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-oem-5.10 - 5.10.0-1038.40

---------------
linux-oem-5.10 (5.10.0-1038.40) focal; urgency=medium

  * CVE-2021-33909
    - SAUCE: seq_file: Disallow extremely large seq buffer allocations

linux-oem-5.10 (5.10.0-1037.38) focal; urgency=medium

  * focal/linux-oem-5.10: 5.10.0-1037.38 -proposed tracker (LP: #1935808)

  * Mute/mic LEDs no function on some HP platfroms (LP: #1934878)
    - ALSA: hda/realtek: fix mute/micmute LEDs for HP ProBook 450 G8
    - ALSA: hda/realtek: fix mute/micmute LEDs for HP ProBook 445 G8
    - ALSA: hda/realtek: fix mute/micmute LEDs for HP ProBook 630 G8

linux-oem-5.10 (5.10.0-1036.37) focal; urgency=medium

  * focal/linux-oem-5.10: 5.10.0-1036.37 -proposed tracker (LP: #1934760)

  * Packaging resync (LP: #1786013)
    - [Packaging] resync getabis
    - [Packaging] update helper scripts

  * mute/micmute LEDs no function on HP EliteBook 830 G8 Notebook PC
    (LP: #1934239)
    - ALSA: hda/realtek: fix mute/micmute LEDs for HP EliteBook 830 G8 Notebook PC

  * Add l2tp.sh in net from ubuntu_kernel_selftests back (LP: #1934293)
    - Revert "UBUNTU: SAUCE: selftests/net -- disable l2tp.sh test"

  * devlink_port_split in net from ubuntu_kernel_selftests linux ADT test
    failure with linux/5.11.0-18.19 ( list index out of range) (LP: #1928889)
    - selftests: net: devlink_port_split.py: skip the test if no devlink device

  * icmp_redirect.sh in net from ubuntu_kernel_selftests failed on F-OEM-5.6 /
    F-OEM-5.10 / F-OEM-5.13 / F / G / H (LP: #1880645)
    - selftests: icmp_redirect: support expected failures

linux-oem-5.10 (5.10.0-1035.36) focal; urgency=medium

  * focal/linux-oem-5.10: 5.10.0-1035.36 -proposed tracker (LP: #1932479)

  * Packaging resync (LP: #1786013)
    - update dkms package versions

  * XPS 9510 (TGL) Screen Brightness could not be changed (LP: #1933566)
    - SAUCE: drm/i915: Force DPCD backlight mode for Dell XPS 9510(TGL)

  * mute/micmute LEDs no function on HP EliteBook x360 830 G8 (LP: #1933508)
    - ALSA: hda/realtek: fix mute/micmute LEDs for HP EliteBook x360 830 G8

  * Focal update: v5.10.46 upstream stable release (LP: #1933367)
    - dmaengine: idxd: add missing dsa driver unregister
    - dmaengine: fsl-dpaa2-qdma: Fix error return code in two functions
    - dmaengine: xilinx: dpdma: initialize registers before request_irq
    - dmaengine: ALTERA_MSGDMA depends on HAS_IOMEM
    - dmaengine: QCOM_HIDMA_MGMT depends on HAS_IOMEM
    - dmaengine: SF_PDMA depends on HAS_IOMEM
    - dmaengine: stedma40: add missing iounmap() on error in d40_probe()
    - afs: Fix an IS_ERR() vs NULL check
    - mm/memory-failure: make sure wait for page writeback in memory_failure
    - kvm: LAPIC: Restore guard to prevent illegal APIC register access
    - fanotify: fix copy_event_to_user() fid error clean up
    - batman-adv: Avoid WARN_ON timing related checks
    - mac80211: fix skb length check in ieee80211_scan_rx()
    - mlxsw: reg: Spectrum-3: Enforce lowest max-shaper burst size of 11
    - mlxsw: core: Set thermal zone polling delay argument to real value at init
    - libbpf: Fixes incorrect rx_ring_setup_done
    - net: ipv4: fix memory...

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

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-hirsute' to 'verification-done-hirsute'. If the problem still exists, change the tag 'verification-needed-hirsute' to 'verification-failed-hirsute'.

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 - 5.4.0-84.94

---------------
linux (5.4.0-84.94) focal; urgency=medium

  * focal/linux: 5.4.0-84.94 -proposed tracker (LP: #1941767)

  * Server boot failure after adding checks for ACPI IRQ override (LP: #1941657)
    - Revert "ACPI: resources: Add checks for ACPI IRQ override"

linux (5.4.0-83.93) focal; urgency=medium

  * focal/linux: 5.4.0-83.93 -proposed tracker (LP: #1940159)

  * fails to launch linux L2 guests on AMD (LP: #1940134) // CVE-2021-3653
    - KVM: nSVM: avoid picking up unsupported bits from L2 in int_ctl
      (CVE-2021-3653)

  * fails to launch linux L2 guests on AMD (LP: #1940134)
    - SAUCE: Revert "UBUNTU: SAUCE: KVM: nSVM: avoid picking up unsupported bits
      from L2 in int_ctl"

linux (5.4.0-82.92) focal; urgency=medium

  * focal/linux: 5.4.0-82.92 -proposed tracker (LP: #1939799)

  * Packaging resync (LP: #1786013)
    - debian/dkms-versions -- update from kernel-versions (main/2021.08.16)

  * CVE-2021-3656
    - SAUCE: KVM: nSVM: always intercept VMLOAD/VMSAVE when nested

  * CVE-2021-3653
    - SAUCE: KVM: nSVM: avoid picking up unsupported bits from L2 in int_ctl

  * [regression] USB device is not detected during boot (LP: #1939638)
    - SAUCE: Revert "usb: core: reduce power-on-good delay time of root hub"

  * dev_forward_skb: do not scrub skb mark within the same name space
    (LP: #1935040)
    - dev_forward_skb: do not scrub skb mark within the same name space

  * XPS 9510 (TGL) Screen Brightness could not be changed (LP: #1933566)
    - SAUCE: drm/i915: Force DPCD backlight mode for Dell XPS 9510(TGL)

  * Acer Aspire 5 sound driver issues (LP: #1930188)
    - ALSA: hda/realtek: headphone and mic don't work on an Acer laptop

  * Sony Dualshock 4 usb dongle crashes the whole system (LP: #1935846)
    - HID: sony: Workaround for DS4 dongle hotplug kernel crash.

  * [21.10 FEAT] KVM: Provide a secure guest indication (LP: #1933173)
    - s390/uv: add prot virt guest/host indication files
    - s390/uv: fix prot virt host indication compilation

  * Skip rtcpie test in kselftests/timers if the default RTC device does not
    exist (LP: #1937991)
    - selftests: timers: rtcpie: skip test if default RTC device does not exist

  * Focal update: v5.4.133 upstream stable release (LP: #1938713)
    - drm/mxsfb: Don't select DRM_KMS_FB_HELPER
    - drm/zte: Don't select DRM_KMS_FB_HELPER
    - drm/amd/amdgpu/sriov disable all ip hw status by default
    - drm/vc4: fix argument ordering in vc4_crtc_get_margins()
    - net: pch_gbe: Use proper accessors to BE data in pch_ptp_match()
    - drm/amd/display: fix use_max_lb flag for 420 pixel formats
    - hugetlb: clear huge pte during flush function on mips platform
    - atm: iphase: fix possible use-after-free in ia_module_exit()
    - mISDN: fix possible use-after-free in HFC_cleanup()
    - atm: nicstar: Fix possible use-after-free in nicstar_cleanup()
    - net: Treat __napi_schedule_irqoff() as __napi_schedule() on PREEMPT_RT
    - drm/mediatek: Fix PM reference leak in mtk_crtc_ddp_hw_init()
    - reiserfs: add check for invalid 1st journal block
    - drm/virtio: Fix double free on probe failure
    - dr...

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 5.11.0-34.36

---------------
linux (5.11.0-34.36) hirsute; urgency=medium

  * hirsute/linux: 5.11.0-34.36 -proposed tracker (LP: #1941766)

  * Server boot failure after adding checks for ACPI IRQ override (LP: #1941657)
    - Revert "ACPI: resources: Add checks for ACPI IRQ override"

linux (5.11.0-33.35) hirsute; urgency=medium

  * hirsute/linux: 5.11.0-33.35 -proposed tracker (LP: #1940101)

  * libvirtd fails to create VM (LP: #1940107)
    - sched: Stop PF_NO_SETAFFINITY from being inherited by various init system
      threads

linux (5.11.0-32.34) hirsute; urgency=medium

  * hirsute/linux: 5.11.0-32.34 -proposed tracker (LP: #1939769)

  * Packaging resync (LP: #1786013)
    - debian/dkms-versions -- update from kernel-versions (main/2021.08.16)

  * CVE-2021-3656
    - SAUCE: KVM: nSVM: always intercept VMLOAD/VMSAVE when nested

  * CVE-2021-3653
    - SAUCE: KVM: nSVM: avoid picking up unsupported bits from L2 in int_ctl

  * [regression] USB device is not detected during boot (LP: #1939638)
    - SAUCE: Revert "usb: core: reduce power-on-good delay time of root hub"

  * Support builtin revoked certificates (LP: #1932029)
    - [Packaging] build canonical-revoked-certs.pem from branch/arch certs
    - [Packaging] Revoke 2012 UEFI signing certificate as built-in
    - [Config] Configure CONFIG_SYSTEM_REVOCATION_KEYS with revoked keys

  * Support importing mokx keys into revocation list from the mok table
    (LP: #1928679)
    - SAUCE: integrity: add informational messages when revoking certs

  * Support importing mokx keys into revocation list from the mok table
    (LP: #1928679) // CVE-2020-26541 when certificates are revoked via
    MokListXRT.
    - SAUCE: integrity: Load mokx certs from the EFI MOK config table

  * Include product_sku info to modalias (LP: #1938143)
    - firmware/dmi: Include product_sku info to modalias

  * Fix Ethernet not working by hotplug - RTL8106E (LP: #1930645)
    - net: phy: rename PHY_IGNORE_INTERRUPT to PHY_MAC_INTERRUPT
    - SAUCE: r8169: Use PHY_POLL when RTL8106E enable ASPM

  * [SRU][H/OEM-5.10/OEM-5.13/U] Fix system hang after unplug tbt dock
    (LP: #1938689)
    - SAUCE: igc: fix page fault when thunderbolt is unplugged

  * [Regression] Audio card [8086:9d71] not detected after upgrade from linux
    5.4 to 5.8 (LP: #1915117)
    - [Config] set CONFIG_SND_SOC_INTEL_SKYLAKE_HDAUDIO_CODEC to y

  * Backlight (screen brightness) on Lenovo P14s AMD Gen2 inop (LP: #1934557)
    - drm/amdgpu/display: only enable aux backlight control for OLED panels

  * Touchpad not working with ASUS TUF F15 (LP: #1937056)
    - pinctrl: tigerlake: Fix GPIO mapping for newer version of software

  * dev_forward_skb: do not scrub skb mark within the same name space
    (LP: #1935040)
    - dev_forward_skb: do not scrub skb mark within the same name space

  * Fix display output on HP hybrid GFX laptops (LP: #1936296)
    - drm/i915: Invoke another _DSM to enable MUX on HP Workstation laptops

  * [SRU][OEM-5.10/H] UBUNTU: SAUCE: Fix backlight control on Samsung 16727
    panel (LP: #1930527)
    - SAUCE: drm/i915: Force DPCD backlight mode for Samsung 16727 pa...