[Intel-gfx] [PATCH 2/2] drm/i915/edp/jsl: Update vswing table for HBR and HBR2
Surendrakumar Upadhyay, TejaskumarX
tejaskumarx.surendrakumar.upadhyay at intel.com
Mon Sep 28 16:34:18 UTC 2020
________________________________
From: Jani Nikula <jani.nikula at linux.intel.com>
Sent: Monday, September 28, 2020 7:13 PM
To: Surendrakumar Upadhyay, TejaskumarX <tejaskumarx.surendrakumar.upadhyay at intel.com>; Vivi, Rodrigo <rodrigo.vivi at intel.com>; airlied at linux.ie <airlied at linux.ie>; daniel at ffwll.ch <daniel at ffwll.ch>; intel-gfx at lists.freedesktop.org <intel-gfx at lists.freedesktop.org>; dri-devel at lists.freedesktop.org <dri-devel at lists.freedesktop.org>; linux-kernel at vger.kernel.org <linux-kernel at vger.kernel.org>; Ausmus, James <james.ausmus at intel.com>; Roper, Matthew D <matthew.d.roper at intel.com>; Souza, Jose <jose.souza at intel.com>; ville.syrjala at linux.intel.com <ville.syrjala at linux.intel.com>; De Marchi, Lucas <lucas.demarchi at intel.com>; Pandey, Hariom <hariom.pandey at intel.com>
Subject: Re: [Intel-gfx] [PATCH 2/2] drm/i915/edp/jsl: Update vswing table for HBR and HBR2
On Mon, 28 Sep 2020, Tejas Upadhyay <tejaskumarx.surendrakumar.upadhyay at intel.com> wrote:
> JSL has update in vswing table for eDP
I've thought the TLA for Jasper Lake is JSP, not JSL. At least we have
PCH_JSP for Jasper Lake PCH.
>
> BSpec: 21257
> Signed-off-by: Tejas Upadhyay <tejaskumarx.surendrakumar.upadhyay at intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_ddi.c | 67 ++++++++++++++++++++++--
> 1 file changed, 64 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> index 4d06178cd76c..fa08463bcf2e 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -582,6 +582,34 @@ static const struct cnl_ddi_buf_trans ehl_combo_phy_ddi_translations_dp[] = {
> { 0x6, 0x7F, 0x3F, 0x00, 0x00 }, /* 900 900 0.0 */
> };
>
> +static const struct cnl_ddi_buf_trans jsl_combo_phy_ddi_translations_edp_hbr[] = {
> + /* NT mV Trans mV db */
> + { 0x8, 0x7F, 0x3F, 0x00, 0x00 }, /* 200 200 0.0 */
> + { 0x8, 0x7F, 0x38, 0x00, 0x07 }, /* 200 250 1.9 */
> + { 0x1, 0x7F, 0x33, 0x00, 0x0C }, /* 200 300 3.5 */
> + { 0xA, 0x35, 0x36, 0x00, 0x09 }, /* 200 350 4.9 */
> + { 0x8, 0x7F, 0x3F, 0x00, 0x00 }, /* 250 250 0.0 */
> + { 0x1, 0x7F, 0x38, 0x00, 0x07 }, /* 250 300 1.6 */
> + { 0xA, 0x35, 0x35, 0x00, 0x0A }, /* 250 350 2.9 */
> + { 0x1, 0x7F, 0x3F, 0x00, 0x00 }, /* 300 300 0.0 */
> + { 0xA, 0x35, 0x38, 0x00, 0x07 }, /* 300 350 1.3 */
> + { 0xA, 0x35, 0x3F, 0x00, 0x00 }, /* 350 350 0.0 */
> +};
> +
> +static const struct cnl_ddi_buf_trans jsl_combo_phy_ddi_translations_edp_hbr2[] = {
> + /* NT mV Trans mV db */
> + { 0x8, 0x7F, 0x3F, 0x00, 0x00 }, /* 200 200 0.0 */
> + { 0x8, 0x7F, 0x3F, 0x00, 0x00 }, /* 200 250 1.9 */
> + { 0x1, 0x7F, 0x3D, 0x00, 0x02 }, /* 200 300 3.5 */
> + { 0xA, 0x35, 0x38, 0x00, 0x07 }, /* 200 350 4.9 */
> + { 0x8, 0x7F, 0x3F, 0x00, 0x00 }, /* 250 250 0.0 */
> + { 0x1, 0x7F, 0x3F, 0x00, 0x00 }, /* 250 300 1.6 */
> + { 0xA, 0x35, 0x3A, 0x00, 0x05 }, /* 250 350 2.9 */
> + { 0x1, 0x7F, 0x3F, 0x00, 0x00 }, /* 300 300 0.0 */
> + { 0xA, 0x35, 0x38, 0x00, 0x07 }, /* 300 350 1.3 */
> + { 0xA, 0x35, 0x3F, 0x00, 0x00 }, /* 350 350 0.0 */
> +};
> +
> struct icl_mg_phy_ddi_buf_trans {
> u32 cri_txdeemph_override_11_6;
> u32 cri_txdeemph_override_5_0;
> @@ -1069,7 +1097,6 @@ icl_get_mg_buf_trans(struct intel_encoder *encoder, int type, int rate,
> *n_entries = ARRAY_SIZE(icl_mg_phy_ddi_translations_rbr_hbr);
> return icl_mg_phy_ddi_translations_rbr_hbr;
> }
> -
> static const struct cnl_ddi_buf_trans *
> ehl_get_combo_buf_trans(struct intel_encoder *encoder, int type, int rate,
> int *n_entries)
> @@ -1098,6 +1125,34 @@ ehl_get_combo_buf_trans(struct intel_encoder *encoder, int type, int rate,
> }
> }
>
> +static const struct cnl_ddi_buf_trans *
> +jsl_get_combo_buf_trans(struct intel_encoder *encoder, int type, int rate,
> + int *n_entries)
> +{
> + struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> +
> + switch (type) {
> + case INTEL_OUTPUT_HDMI:
> + *n_entries = ARRAY_SIZE(icl_combo_phy_ddi_translations_hdmi);
> + return icl_combo_phy_ddi_translations_hdmi;
> + case INTEL_OUTPUT_EDP:
> + if (dev_priv->vbt.edp.low_vswing) {
> + if (rate > 270000) {
> + *n_entries = ARRAY_SIZE(jsl_combo_phy_ddi_translations_edp_hbr2);
> + return jsl_combo_phy_ddi_translations_edp_hbr2;
> + } else {
> + *n_entries = ARRAY_SIZE(jsl_combo_phy_ddi_translations_edp_hbr);
> + return jsl_combo_phy_ddi_translations_edp_hbr;
> + }
> + }
> + /* fall through */
> + default:
> + /* All combo DP and eDP ports that do not support low_vswing */
> + *n_entries = ARRAY_SIZE(icl_combo_phy_ddi_translations_dp_hbr2);
> + return icl_combo_phy_ddi_translations_dp_hbr2;
> + }
> +}
> +
> static const struct cnl_ddi_buf_trans *
> tgl_get_combo_buf_trans(struct intel_encoder *encoder, int type, int rate,
> int *n_entries)
> @@ -2265,9 +2320,12 @@ static u8 intel_ddi_dp_voltage_max(struct intel_dp *intel_dp)
> tgl_get_dkl_buf_trans(encoder, encoder->type,
> intel_dp->link_rate, &n_entries);
> } else if (INTEL_GEN(dev_priv) == 11) {
> - if (IS_ELKHARTLAKE(dev_priv))
> + if (IS_JASPERLAKE(dev_priv))
> + jsl_get_combo_buf_trans(encoder, encoder->type,
> + intel_dp->link_rate, &n_entries);
> + else if (IS_ELKHARTLAKE(dev_priv))
> ehl_get_combo_buf_trans(encoder, encoder->type,
> - intel_dp->link_rate, &n_entries);
> + intel_dp->link_rate, &n_entries);
This is a good example of a potential trap that having IS_ELKHARTLAKE()
cover both ELK and JSP creates. An unsuspecting coder might change the
if ladder to have IS_ELKHARTLAKE() first, and the subsequent
IS_JASPERLAKE() branch would never be taken.
BR,
Jani.
Tejas : In that case I will put attention note in comment about platform checks such that ladder distrubance can be avoided. What you suggest?
> else if (intel_phy_is_combo(dev_priv, phy))
> icl_get_combo_buf_trans(encoder, encoder->type,
> intel_dp->link_rate, &n_entries);
> @@ -2454,6 +2512,9 @@ static void icl_ddi_combo_vswing_program(struct intel_encoder *encoder,
> if (INTEL_GEN(dev_priv) >= 12)
> ddi_translations = tgl_get_combo_buf_trans(encoder, type, rate,
> &n_entries);
> + else if (IS_JASPERLAKE(dev_priv))
> + ddi_translations = jsl_get_combo_buf_trans(encoder, type, rate,
> + &n_entries);
> else if (IS_ELKHARTLAKE(dev_priv))
> ddi_translations = ehl_get_combo_buf_trans(encoder, type, rate,
> &n_entries);
--
Jani Nikula, Intel Open Source Graphics Center
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