From: "Ville Syrjälä" <ville.syrjala@linux.intel.com>
To: Imre Deak <imre.deak@intel.com>
Cc: intel-gfx@lists.freedesktop.org
Subject: Re: [Intel-gfx] [PATCH 1/2] drm/i915/ddi: Don't frob the DP link scramble disabling flag
Date: Tue, 14 Jul 2020 19:05:32 +0300 [thread overview]
Message-ID: <20200714160532.GK6112@intel.com> (raw)
In-Reply-To: <20200714153141.10280-1-imre.deak@intel.com>
On Tue, Jul 14, 2020 at 06:31:40PM +0300, Imre Deak wrote:
> According to BSpec this flag should not be changed while the DDI
> function is enabled. On BDW+ the DP_TP_CTL register spec also states it
> explicitly that the HW takes care of enabling/disabling the scrambling
> for training patterns (and it must stay enabled for normal pixel
> output). Assume that this HW automatic handling of scrambling is also
> true for HSW.
It is at least marked as debug only for hsw.
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> BSpec: 8013, 7557, 50484
>
> Signed-off-by: Imre Deak <imre.deak@intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_ddi.c | 8 +-------
> 1 file changed, 1 insertion(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> index 2c484b55bcdf..c467f18d5e1b 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -4037,8 +4037,7 @@ static void intel_ddi_prepare_link_retrain(struct intel_dp *intel_dp)
> intel_wait_ddi_buf_idle(dev_priv, port);
> }
>
> - dp_tp_ctl = DP_TP_CTL_ENABLE |
> - DP_TP_CTL_LINK_TRAIN_PAT1 | DP_TP_CTL_SCRAMBLE_DISABLE;
> + dp_tp_ctl = DP_TP_CTL_ENABLE | DP_TP_CTL_LINK_TRAIN_PAT1;
> if (intel_dp->link_mst)
> dp_tp_ctl |= DP_TP_CTL_MODE_MST;
> else {
> @@ -4066,11 +4065,6 @@ static void intel_ddi_set_link_train(struct intel_dp *intel_dp,
>
> temp = intel_de_read(dev_priv, intel_dp->regs.dp_tp_ctl);
>
> - if (dp_train_pat & DP_LINK_SCRAMBLING_DISABLE)
> - temp |= DP_TP_CTL_SCRAMBLE_DISABLE;
> - else
> - temp &= ~DP_TP_CTL_SCRAMBLE_DISABLE;
> -
> temp &= ~DP_TP_CTL_LINK_TRAIN_MASK;
> switch (dp_train_pat & train_pat_mask) {
> case DP_TRAINING_PATTERN_DISABLE:
> --
> 2.23.1
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
--
Ville Syrjälä
Intel
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Intel-gfx mailing list
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next prev parent reply other threads:[~2020-07-14 16:05 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-14 15:31 [Intel-gfx] [PATCH 1/2] drm/i915/ddi: Don't frob the DP link scramble disabling flag Imre Deak
2020-07-14 15:31 ` [Intel-gfx] [PATCH 2/2] drm/i915/ddi: Don't rewrite DDI_BUF_CTL reg during DP link training Imre Deak
2020-07-14 16:08 ` Ville Syrjälä
2020-07-14 16:20 ` Imre Deak
2020-07-14 16:05 ` Ville Syrjälä [this message]
2020-07-14 16:34 ` [Intel-gfx] ✓ Fi.CI.BAT: success for series starting with [1/2] drm/i915/ddi: Don't frob the DP link scramble disabling flag Patchwork
2020-07-14 18:17 ` [Intel-gfx] ✓ Fi.CI.IGT: " Patchwork
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