[Intel-gfx] [PATCH] drm/i915: don't force VDD on when shutting down a panel

[Paulo Zanoni]

2013/12/4 Jesse Barnes <jbarnes at virtuousgeek.org>:
> This causes trouble on some VLV systems, and generally costs power
> elsewhere.
>
> If this ends up causing trouble, it could just mean we need to get rid
> of VDD force enable everywhere, and move to a pure PPS based DP training
> sequence.
>
> References: https://bugs.freedesktop.org/show_bug.cgi?id=69693
> Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
> ---
>  drivers/gpu/drm/i915/intel_dp.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index 1e372d5..cb33b67 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -1236,9 +1236,7 @@ void ironlake_edp_panel_off(struct intel_dp *intel_dp)
>         WARN(!intel_dp->want_panel_vdd, "Need VDD to turn off panel\n");
>
>         pp = ironlake_get_pp_control(intel_dp);
> -       /* We need to switch off panel power _and_ force vdd, for otherwise some
> -        * panels get very unhappy and cease to work. */
> -       pp &= ~(POWER_TARGET_ON | EDP_FORCE_VDD | PANEL_POWER_RESET | EDP_BLC_ENABLE);
> +       pp &= ~(POWER_TARGET_ON | PANEL_POWER_RESET | EDP_BLC_ENABLE);

My understanding is that now you'll keep VDD enabled forever, so the
panel power is not really being disabled. So the commit message and
title seem wrong. Is this really what you wanted?

Please take a look at the last patches of the runtime PM series (I
made them part of the runtime PM series just for rebasing purposes).



>
>         pp_ctrl_reg = _pp_ctrl_reg(intel_dp);
>
> --
> 1.8.4.2
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx



-- 
Paulo Zanoni