kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-11-10 20:48:12 +00:00
Code Issues Releases Packages Activity

drm/i915/vrr: Add per-CRTC vrr/cmrr debugfs control

Browse source 
Add a per-CRTC debugfs file 'intel_vrr_target_refresh_rate' that lets
the user force a CMRR target refresh rate and video-mode requirement.

The file uses a "numerator/denominator" format:
  - numerator:   requested refresh rate in milli-Hz
                 (refresh rate in Hz * 1000, e.g. 60000 for 60 Hz)
  - denominator: 1000 for a 1:1 ratio (no video timing) or
                 1001 for the 1000/1001 video timing

Reading the file reports the currently stored values; writing updates
them. The file is created only on platforms with VRR and CMRR support.

--v2:
- Drop the "vrr" debugfs subdirectory and expose a single flat,
  intel_-prefixed "intel_vrr_cmrr" file (Jani, Nikula)
- Rename struct intel_crtc.cmrr to force_cmrr to make its purpose
  explicit (Chaitanya)
- Fix parse comment: numerator unit is milli-Hz, not KHz (Chaitanya)
- Add debugfs/intel_ prefixes to the debugfs handler functions (Chaitanya)
- Expand commit message with debugfs entry semantics (Chaitanya)

--v3:
- Rename debugfs function and file name (Chaitanya)
- Remove railing new line at EOF (Chaitanya)
- Update CMRR guard conditions (Chaitanya)
- Add 0/0 default case. (Ramanaidu)

--v4:
- Correct CMRR guard check while creating debugfs

--v5:
- Commit message update (Chaitanya)
- Add support for 0/0 writing (Validation)

Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com>
Reviewed-by: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Link: https://patch.msgid.link/20260730105919.3913412-4-mitulkumar.ajitkumar.golani@intel.com
This commit is contained in:
Mitul Golani 2026-07-30 16:29:10 +05:30 • committed by Suraj Kandpal
commit 9edafeb040
4 changed files with 121 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files