i915 doesn't support some high pixel clock 4k * 60Hz monitors

[jeremyszu]

[Impact]

 * Some 4K monitors can not display as maximum resolution from i915 graphic.

 * In some 4k monitors, it's support higher pixel clock

The following is the case I have:

Modeline "Mode 0" 533.25 3840 3888 3920 4000 2160 2163 2168 2222 +hsync -vsync

Which will be dropped because the mode rate is greater than i915 maximum data rate.
kernel: [drm:drm_mode_debug_printmodeline [drm]] Modeline "3840x2160": 60 533250 3840 3888 3920 4000 2160 2163 2168 2222 0x48 0x9
kernel: [drm:drm_mode_prune_invalid [drm]] Not using 3840x2160 mode: CLOCK_HIGH

The BDB version of Intel vBIOS is 237
kernel: i915 0000:00:02.0: [drm:intel_bios_init [i915]] VBT signature "$VBT TIGERLAKE ", BDB version 237

In old i915 parsing rule (for greater than v216), the common rate is decoded as 16200
kernel: i915 0000:00:02.0: [drm:intel_dp_print_rates [i915]] common rates: 162000

Since the Intel updated the parsing rule (for greater then 230). the common rate is up to 540000
kernel: i915 0000:00:02.0: [drm:intel_dp_print_rates [i915]] common rates: 162000, 270000,
 540000

There are 4 lanes support.
i915 0000:00:02.0: [drm:intel_dp_link_train_phy [i915]] [CONNECTOR:184:DP-2] Link
Training passed at link rate = 162000, lane count = 4, at DPRX

In this monitor, the max rate (max_link_clock * max_lanes) is:
162000 * 4 = 648000 # if using old parsing rule (> 210)
540000 * 4 = 2160000 # if using updated parsing rule (> 230)

the maximum mode rate is
DIV_ROUND_UP(pixel_clock * bpp, 8);

the bpp here is minimum bpp, which is 6 * 3 = 18
...
 max bpc: 12
  range: (6, 12)
...
thus:
533250 * 18 + 8 - 1 / 8 = 1199813 # this is maximum mode rate of this monitor.

[Fix]

 * It needs to use the updated parsing table (intel BDB table version > 230) for supporting high pixel clock monitors.

[Test Plan]

 * Steps to reproduce
  1. Connect a high pixel clock monitor (533KHz in my case) to i915 graphic which vbios version is v237 (In my case:
 ModelName "U2879G6"
 VendorName "AOC"

  2. Check the display setting, expect a 3840*2160*60Hz option but there is not 3840*2160*60Hz option.

 * if upgrade drm debugging level then you will see the modeline be dropped because of high clock.
kernel: [drm:drm_mode_prune_invalid [drm]] Not using 3840x2160 mode: CLOCK_HIGH

 * after applying the change, the resolution work good.

[Where problems could occur]

 * This change considered the backward compatibility, which will check the BDB version before applying different parsing rule.

 * From software perspective, the monitor will show nothing if Intel vBIOS using BDB > 230 with undefined dp_max_link_rate field.

 * Otherwise, it looks quite ok.

[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 1922372

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.

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 5.11.0-14.15

---------------
linux (5.11.0-14.15) hirsute; urgency=medium

  * hirsute/linux: 5.11.0-14.15 -proposed tracker (LP: #1923103)

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

  * Include Infiniband Peer Memory interface (LP: #1923104)
    - SAUCE: RDMA/core: Introduce peer memory interface

  * Hirsute update: v5.11.12 upstream stable release (LP: #1923069)
    - arm64: mm: correct the inside linear map range during hotplug check
    - virtiofs: Fail dax mount if device does not support it
    - ext4: shrink race window in ext4_should_retry_alloc()
    - ext4: fix bh ref count on error paths
    - fs: nfsd: fix kconfig dependency warning for NFSD_V4
    - rpc: fix NULL dereference on kmalloc failure
    - iomap: Fix negative assignment to unsigned sis->pages in
      iomap_swapfile_activate
    - ASoC: rt1015: fix i2c communication error
    - ASoC: rt5640: Fix dac- and adc- vol-tlv values being off by a factor of 10
    - ASoC: rt5651: Fix dac- and adc- vol-tlv values being off by a factor of 10
    - ASoC: sgtl5000: set DAP_AVC_CTRL register to correct default value on probe
    - ASoC: es8316: Simplify adc_pga_gain_tlv table
    - ASoC: soc-core: Prevent warning if no DMI table is present
    - ASoC: cs42l42: Fix Bitclock polarity inversion
    - ASoC: cs42l42: Fix channel width support
    - ASoC: cs42l42: Fix mixer volume control
    - ASoC: cs42l42: Always wait at least 3ms after reset
    - NFSD: fix error handling in NFSv4.0 callbacks
    - ASoC: mediatek: mt8192: fix tdm out data is valid on rising edge
    - kernel: freezer should treat PF_IO_WORKER like PF_KTHREAD for freezing
    - vhost: Fix vhost_vq_reset()
    - io_uring: fix ->flags races by linked timeouts
    - io_uring: halt SQO submission on ctx exit
    - scsi: st: Fix a use after free in st_open()
    - scsi: qla2xxx: Fix broken #endif placement
    - staging: comedi: cb_pcidas: fix request_irq() warn
    - staging: comedi: cb_pcidas64: fix request_irq() warn
    - ASoC: rt5659: Update MCLK rate in set_sysclk()
    - ASoC: rt711: add snd_soc_component remove callback
    - thermal/core: Add NULL pointer check before using cooling device stats
    - locking/ww_mutex: Simplify use_ww_ctx & ww_ctx handling
    - locking/ww_mutex: Fix acquire/release imbalance in
      ww_acquire_init()/ww_acquire_fini()
    - nvmet-tcp: fix kmap leak when data digest in use
    - io_uring: imply MSG_NOSIGNAL for send[msg]()/recv[msg]() calls
    - Revert "PM: ACPI: reboot: Use S5 for reboot"
    - nouveau: Skip unvailable ttm page entries
    - static_call: Align static_call_is_init() patching condition
    - ext4: do not iput inode under running transaction in ext4_rename()
    - io_uring: call req_set_fail_links() on short send[msg]()/recv[msg]() with
      MSG_WAITALL
    - net: mvpp2: fix interrupt mask/unmask skip condition
    - mptcp: deliver ssk errors to msk
    - mptcp: fix poll after shutdown
    - mptcp: init mptcp request socket earlier
    - mptcp: add a missing retransmission timer scheduling
    - flow_dissector: fix TTL and TOS dissection on IPv4 fragments
    - mptcp: fix DATA_FIN processing f...

[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 - 5.10.0-1025.26

---------------
linux-oem-5.10 (5.10.0-1025.26) focal; urgency=medium

  * focal/linux-oem-5.10: 5.10.0-1025.26 -proposed tracker (LP: #1926155)

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

  * CirrusLogic: Cracking noises appears in built-in speaker when output volume
    is set >80% (LP: #1924997)
    - SAUCE: ALSA: hda/cirrus: Use CS8409 Equalizer to fix abnormal sounds on
      Bullseye

 -- Timo Aaltonen <email address hidden> Mon, 26 Apr 2021 16:18:11 +0300