drm/i915: Implement Audio WA_14020863754

WA_14020863754: Corner case with Min Hblank Fix can cause
audio hang

Issue: Previously a fix was made to avoid issues with extremely
small hblanks, called the "Min Hblank Fix". However, this can
potentially cause an audio hang.

Workaround :
During "Audio Programming Sequence" Audio Enabling -
When DP mode is enabled Set mmio offset 0x65F1C bit 18 = 1b,
before step #1 "Enable audio Presence Detect"

During "Audio Programming Sequence" Audio Disabling -
When DP mode is enabled Clear mmio offset 0x65F1C bit 18 = 0b,
after step #6 "Disable Audio PD (Presence Detect)"
If not clearing PD bit, must also not clear 0x65F1C bit 18 (leave = 1b)

v2: Update the platform checks (Jani Nikula)

v3: Limited the WA to LNL and BMG, added a helper (Matt Roper)

v4: Updated the bit naming, fixed redundant if statement

Signed-off-by: Uma Shankar <uma.shankar@intel.com>
Reviewed-by: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240509053508.2807834-1-uma.shankar@intel.com
This commit is contained in:
Uma Shankar 2024-05-09 11:05:08 +05:30
commit 56c12ec72a
2 changed files with 18 additions and 0 deletions