Re: [PATCH] drm/i915/alpm: Fix swapped wake lines in LOBF late config

["Nautiyal, Ankit K" <ankit.k.nautiyal@intel.com>]

On 8/25/2026 11:22 AM, Animesh Manna wrote:
> intel_alpm_lobf_compute_config_late() selected the main-link wake time
> with the two cases inverted: when aux-less wake was supported it used the
> aux-wake io_wake_lines, and otherwise the aux_less_wake_lines. This is the
> opposite of the mapping used in intel_psr_compute_config_late() and of the
> underlying meaning of the two values.
>
> As a result the LOBF enable decision (scl + guardband > first_sdp_position
> + waketime_in_lines) was computed against the wrong wake time, so LOBF
> could be enabled or rejected incorrectly.
>
> Use aux_less_wake_lines when aux-less wake is supported and io_wake_lines
> otherwise, matching the PSR path.
>
> Cc: Jouni Högander <jouni.hogander@intel.com>
> Cc: Ankit Nautiyal <ankit.k.nautiyal@intel.com
> Cc: stable@vger.kernel.org
> Fixes: 9090fa44a6d45 ("drm/i915/alpm: Compute LOBF late after guardband is already determined")


I think the fixes should be below commit:

Fixes: 15438b325987 ("drm/i915/alpm: Add compute config for lobf")
Cc: <stable@vger.kernel.org> # v6.11+

Regards,

Ankit

> Assisted-by: Claude:claude-opus-4-8
> Signed-off-by: Animesh Manna <animesh.manna@intel.com>
> ---
>   drivers/gpu/drm/i915/display/intel_alpm.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_alpm.c b/drivers/gpu/drm/i915/display/intel_alpm.c
> index f1383764b702..559fe6d14c01 100644
> --- a/drivers/gpu/drm/i915/display/intel_alpm.c
> +++ b/drivers/gpu/drm/i915/display/intel_alpm.c
> @@ -314,9 +314,9 @@ void intel_alpm_lobf_compute_config_late(struct intel_dp *intel_dp,
>   	 */
>   	first_sdp_position = adjusted_mode->crtc_vtotal - adjusted_mode->crtc_vsync_start;
>   	if (intel_alpm_aux_less_wake_supported(intel_dp))
> -		waketime_in_lines = crtc_state->alpm_state.io_wake_lines;
> -	else
>   		waketime_in_lines = crtc_state->alpm_state.aux_less_wake_lines;
> +	else
> +		waketime_in_lines = crtc_state->alpm_state.io_wake_lines;
>   
>   	crtc_state->has_lobf = (crtc_state->set_context_latency + crtc_state->vrr.guardband) >
>   			       (first_sdp_position + waketime_in_lines);