Re: [PATCH v2 09/23] drm/i915: Factor out common parts from TypeC port handling functions

Ville Syrjälä
2019-06-25T13:05:58Z

On Thu, Jun 20, 2019 at 05:05:46PM +0300, Imre Deak wrote:
> Factor out helpers reading/parsing the TypeC specific registers, making
> current users of them clearer and letting us use them later.
>
> While at it also:
> - Simplify icl_tc_phy_connect() with an early return in legacy mode.
> - Simplify the live status check using one bitmask for all HPD bits.
> - Remove a micro-optimisation of the repeated safe-mode clearing.
> - Make sure we fix the legacy port flag in all cases.
>
> Except for the last two, no functional changes.
>
> v2:
> - Don't do reg reads at variable declarations. (Jani)
> - Prevent constant truncated compiler warning when assigning the
> valid_hpd_mask. (Nick)
> - s/intel_tc_port_get_lane_info/intel_tc_port_get_lane_mask/ (Ville)
>
> Cc: José Roberto de Souza <jose.souza@intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
> Cc: Jani Nikula <jani.nikula@intel.com>
> Cc: Nick Desaulniers <ndesaulniers@google.com>
> Signed-off-by: Imre Deak <imre.deak@intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_ddi.c | 11 +-
> drivers/gpu/drm/i915/display/intel_tc.c | 185 ++++++++++++++---------
> drivers/gpu/drm/i915/display/intel_tc.h | 1 +
> 3 files changed, 116 insertions(+), 81 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> index c9143e2a6994..2be7cdc319ba 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -2996,8 +2996,7 @@ static void icl_program_mg_dp_mode(struct intel_digital_port *intel_dig_port)
> {
> struct drm_i915_private *dev_priv = to_i915(intel_dig_port->base.base.dev);
> enum port port = intel_dig_port->base.port;
> - enum tc_port tc_port = intel_port_to_tc(dev_priv, port);
> - u32 ln0, ln1, lane_info;
> + u32 ln0, ln1, lane_mask;
>
> if (intel_dig_port->tc_mode == TC_PORT_TBT_ALT)
> return;
> @@ -3010,11 +3009,9 @@ static void icl_program_mg_dp_mode(struct intel_digital_port *intel_dig_port)
> ln0 &= ~(MG_DP_MODE_CFG_DP_X1_MODE | MG_DP_MODE_CFG_DP_X2_MODE);
> ln1 &= ~(MG_DP_MODE_CFG_DP_X1_MODE | MG_DP_MODE_CFG_DP_X2_MODE);
>
> - lane_info = (I915_READ(PORT_TX_DFLEXDPSP) &
> - DP_LANE_ASSIGNMENT_MASK(tc_port)) >>
> - DP_LANE_ASSIGNMENT_SHIFT(tc_port);
> + lane_mask = intel_tc_port_get_lane_mask(intel_dig_port);
>
> - switch (lane_info) {
> + switch (lane_mask) {
> case 0x1:
> case 0x4:
> break;
> @@ -3039,7 +3036,7 @@ static void icl_program_mg_dp_mode(struct intel_digital_port *intel_dig_port)
> MG_DP_MODE_CFG_DP_X2_MODE;
> break;
> default:
> - MISSING_CASE(lane_info);
> + MISSING_CASE(lane_mask);
> }
> break;
>
> diff --git a/drivers/gpu/drm/i915/display/intel_tc.c b/drivers/gpu/drm/i915/display/intel_tc.c
> index ca3b11e26474..fbf0a8c9361f 100644
> --- a/drivers/gpu/drm/i915/display/intel_tc.c
> +++ b/drivers/gpu/drm/i915/display/intel_tc.c
> @@ -21,25 +21,34 @@ static const char *tc_port_mode_name(enum tc_port_mode mode)
> return names[mode];
> }
>
> -int intel_tc_port_fia_max_lane_count(struct intel_digital_port *dig_port)
> +u32 intel_tc_port_get_lane_mask(struct intel_digital_port *dig_port)
> {
> struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
> enum tc_port tc_port = intel_port_to_tc(dev_priv, dig_port->base.port);
> + u32 lane_mask;
> +
> + lane_mask = I915_READ(PORT_TX_DFLEXDPSP);
> +
> + return (lane_mask & DP_LANE_ASSIGNMENT_MASK(tc_port)) >>
> + DP_LANE_ASSIGNMENT_SHIFT(tc_port);
> +}
> +
> +int intel_tc_port_fia_max_lane_count(struct intel_digital_port *dig_port)
> +{
> + struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
> intel_wakeref_t wakeref;
> - u32 lane_info;
> + u32 lane_mask;
>
> if (dig_port->tc_mode != TC_PORT_DP_ALT)
> return 4;
>
> - lane_info = 0;
> + lane_mask = 0;
> with_intel_display_power(dev_priv, POWER_DOMAIN_DISPLAY_CORE, wakeref)
> - lane_info = (I915_READ(PORT_TX_DFLEXDPSP) &
> - DP_LANE_ASSIGNMENT_MASK(tc_port)) >>
> - DP_LANE_ASSIGNMENT_SHIFT(tc_port);
> + lane_mask = intel_tc_port_get_lane_mask(dig_port);
>
> - switch (lane_info) {
> + switch (lane_mask) {
> default:
> - MISSING_CASE(lane_info);
> + MISSING_CASE(lane_mask);
> case 1:
> case 2:
> case 4:
> @@ -53,6 +62,73 @@ int intel_tc_port_fia_max_lane_count(struct intel_digital_port *dig_port)
> }
> }
>
> +static void tc_port_fixup_legacy_flag(struct intel_digital_port *dig_port,
> + u32 live_status_mask)
> +{
> + u32 valid_hpd_mask = BIT(TC_PORT_LEGACY);
> +
> + if (!dig_port->tc_legacy_port)
> + valid_hpd_mask = ~valid_hpd_mask;

Might be a bit less confusing if we write this as:

if (legacy)
valid_hpd_mask = LEGACY;
else
valid_hpd_mask = DP_ALT | TBT_ALT;

Otherwise lgtm
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

> +
> + if (!(live_status_mask & ~valid_hpd_mask))
> + return;
> +
> + /* If live status mismatches the VBT flag, trust the live status. */
> + DRM_ERROR("Port %s: live status %08x mismatches the legacy port flag, fix flag\n",
> + dig_port->tc_port_name, live_status_mask);
> +
> + dig_port->tc_legacy_port = !dig_port->tc_legacy_port;
> +}
> +
> +static u32 tc_port_live_status_mask(struct intel_digital_port *dig_port)
> +{
> + struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
> + enum tc_port tc_port = intel_port_to_tc(dev_priv, dig_port->base.port);
> + u32 mask = 0;
> + u32 val;
> +
> + val = I915_READ(PORT_TX_DFLEXDPSP);
> +
> + if (val & TC_LIVE_STATE_TBT(tc_port))
> + mask |= BIT(TC_PORT_TBT_ALT);
> + if (val & TC_LIVE_STATE_TC(tc_port))
> + mask |= BIT(TC_PORT_DP_ALT);
> +
> + if (I915_READ(SDEISR) & SDE_TC_HOTPLUG_ICP(tc_port))
> + mask |= BIT(TC_PORT_LEGACY);
> +
> + /* The sink can be connected only in a single mode. */
> + if (!WARN_ON(hweight32(mask) > 1))
> + tc_port_fixup_legacy_flag(dig_port, mask);
> +
> + return mask;
> +}
> +
> +static bool icl_tc_phy_status_complete(struct intel_digital_port *dig_port)
> +{
> + struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
> + enum tc_port tc_port = intel_port_to_tc(dev_priv, dig_port->base.port);
> +
> + return I915_READ(PORT_TX_DFLEXDPPMS) &
> + DP_PHY_MODE_STATUS_COMPLETED(tc_port);
> +}
> +
> +static void icl_tc_phy_set_safe_mode(struct intel_digital_port *dig_port,
> + bool enable)
> +{
> + struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
> + enum tc_port tc_port = intel_port_to_tc(dev_priv, dig_port->base.port);
> + u32 val;
> +
> + val = I915_READ(PORT_TX_DFLEXDPCSSS);
> +
> + val &= ~DP_PHY_MODE_STATUS_NOT_SAFE(tc_port);
> + if (!enable)
> + val |= DP_PHY_MODE_STATUS_NOT_SAFE(tc_port);
> +
> + I915_WRITE(PORT_TX_DFLEXDPCSSS, val);
> +}
> +
> /*
> * This function implements the first part of the Connect Flow described by our
> * specification, Gen11 TypeC Programming chapter. The rest of the flow (reading
> @@ -76,38 +152,31 @@ int intel_tc_port_fia_max_lane_count(struct intel_digital_port *dig_port)
> */
> static bool icl_tc_phy_connect(struct intel_digital_port *dig_port)
> {
> - struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
> - enum tc_port tc_port = intel_port_to_tc(dev_priv, dig_port->base.port);
> - u32 val;
> + u32 live_status_mask;
>
> if (dig_port->tc_mode != TC_PORT_LEGACY &&
> dig_port->tc_mode != TC_PORT_DP_ALT)
> return true;
>
> - val = I915_READ(PORT_TX_DFLEXDPPMS);
> - if (!(val & DP_PHY_MODE_STATUS_COMPLETED(tc_port))) {
> + if (!icl_tc_phy_status_complete(dig_port)) {
> DRM_DEBUG_KMS("Port %s: PHY not ready\n",
> dig_port->tc_port_name);
> WARN_ON(dig_port->tc_legacy_port);
> return false;
> }
>
> - /*
> - * This function may be called many times in a row without an HPD event
> - * in between, so try to avoid the write when we can.
> - */
> - val = I915_READ(PORT_TX_DFLEXDPCSSS);
> - if (!(val & DP_PHY_MODE_STATUS_NOT_SAFE(tc_port))) {
> - val |= DP_PHY_MODE_STATUS_NOT_SAFE(tc_port);
> - I915_WRITE(PORT_TX_DFLEXDPCSSS, val);
> - }
> + icl_tc_phy_set_safe_mode(dig_port, false);
> +
> + if (dig_port->tc_mode == TC_PORT_LEGACY)
> + return true;
> +
> + live_status_mask = tc_port_live_status_mask(dig_port);
>
> /*
> * Now we have to re-check the live state, in case the port recently
> * became disconnected. Not necessary for legacy mode.
> */
> - if (dig_port->tc_mode == TC_PORT_DP_ALT &&
> - !(I915_READ(PORT_TX_DFLEXDPSP) & TC_LIVE_STATE_TC(tc_port))) {
> + if (!(live_status_mask & BIT(TC_PORT_DP_ALT))) {
> DRM_DEBUG_KMS("Port %s: PHY sudden disconnect\n",
> dig_port->tc_port_name);
> icl_tc_phy_disconnect(dig_port);
> @@ -123,46 +192,35 @@ static bool icl_tc_phy_connect(struct intel_digital_port *dig_port)
> */
> void icl_tc_phy_disconnect(struct intel_digital_port *dig_port)
> {
> - struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
> - enum tc_port tc_port = intel_port_to_tc(dev_priv, dig_port->base.port);
> -
> - /*
> - * TBT disconnection flow is read the live status, what was done in
> - * caller.
> - */
> - if (dig_port->tc_mode == TC_PORT_DP_ALT ||
> - dig_port->tc_mode == TC_PORT_LEGACY) {
> - u32 val;
> -
> - val = I915_READ(PORT_TX_DFLEXDPCSSS);
> - val &= ~DP_PHY_MODE_STATUS_NOT_SAFE(tc_port);
> - I915_WRITE(PORT_TX_DFLEXDPCSSS, val);
> + switch (dig_port->tc_mode) {
> + case TC_PORT_LEGACY:
> + case TC_PORT_DP_ALT:
> + icl_tc_phy_set_safe_mode(dig_port, true);
> + dig_port->tc_mode = TC_PORT_TBT_ALT;
> + break;
> + case TC_PORT_TBT_ALT:
> + /* Nothing to do, we stay in TBT-alt mode */
> + break;
> + default:
> + MISSING_CASE(dig_port->tc_mode);
> }
>
> DRM_DEBUG_KMS("Port %s: mode %s disconnected\n",
> dig_port->tc_port_name,
> tc_port_mode_name(dig_port->tc_mode));
> -
> - dig_port->tc_mode = TC_PORT_TBT_ALT;
> }
>
> static void icl_update_tc_port_type(struct drm_i915_private *dev_priv,
> struct intel_digital_port *intel_dig_port,
> - bool is_legacy, bool is_typec, bool is_tbt)
> + u32 live_status_mask)
> {
> enum tc_port_mode old_mode = intel_dig_port->tc_mode;
>
> - WARN_ON(is_legacy + is_typec + is_tbt != 1);
> -
> - if (is_legacy)
> - intel_dig_port->tc_mode = TC_PORT_LEGACY;
> - else if (is_typec)
> - intel_dig_port->tc_mode = TC_PORT_DP_ALT;
> - else if (is_tbt)
> - intel_dig_port->tc_mode = TC_PORT_TBT_ALT;
> - else
> + if (!live_status_mask)
> return;
>
> + intel_dig_port->tc_mode = fls(live_status_mask) - 1;
> +
> if (old_mode != intel_dig_port->tc_mode)
> DRM_DEBUG_KMS("Port %s: port has mode %s\n",
> intel_dig_port->tc_port_name,
> @@ -182,40 +240,19 @@ static void icl_update_tc_port_type(struct drm_i915_private *dev_priv,
> bool intel_tc_port_connected(struct intel_digital_port *dig_port)
> {
> struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
> - enum port port = dig_port->base.port;
> - enum tc_port tc_port = intel_port_to_tc(dev_priv, port);
> - bool is_legacy, is_typec, is_tbt;
> - u32 dpsp;
> -
> - /*
> - * Complain if we got a legacy port HPD, but VBT didn't mark the port as
> - * legacy. Treat the port as legacy from now on.
> - */
> - if (!dig_port->tc_legacy_port &&
> - I915_READ(SDEISR) & SDE_TC_HOTPLUG_ICP(tc_port)) {
> - DRM_ERROR("Port %s: VBT incorrectly claims port is not TypeC legacy\n",
> - dig_port->tc_port_name);
> - dig_port->tc_legacy_port = true;
> - }
> - is_legacy = dig_port->tc_legacy_port;
> + u32 live_status_mask = tc_port_live_status_mask(dig_port);
>
> /*
> * The spec says we shouldn't be using the ISR bits for detecting
> * between TC and TBT. We should use DFLEXDPSP.
> */
> - dpsp = I915_READ(PORT_TX_DFLEXDPSP);
> - is_typec = dpsp & TC_LIVE_STATE_TC(tc_port);
> - is_tbt = dpsp & TC_LIVE_STATE_TBT(tc_port);
> -
> - if (!is_legacy && !is_typec && !is_tbt) {
> + if (!live_status_mask && !dig_port->tc_legacy_port) {
> icl_tc_phy_disconnect(dig_port);
>
> return false;
> }
>
> - icl_update_tc_port_type(dev_priv, dig_port, is_legacy, is_typec,
> - is_tbt);
> -
> + icl_update_tc_port_type(dev_priv, dig_port, live_status_mask);
> if (!icl_tc_phy_connect(dig_port))
> return false;
>
> diff --git a/drivers/gpu/drm/i915/display/intel_tc.h b/drivers/gpu/drm/i915/display/intel_tc.h
> index ca1735303252..8c338c45796d 100644
> --- a/drivers/gpu/drm/i915/display/intel_tc.h
> +++ b/drivers/gpu/drm/i915/display/intel_tc.h
> @@ -13,6 +13,7 @@ struct intel_digital_port;
> void icl_tc_phy_disconnect(struct intel_digital_port *dig_port);
>
> bool intel_tc_port_connected(struct intel_digital_port *dig_port);
> +u32 intel_tc_port_get_lane_mask(struct intel_digital_port *dig_port);
> int intel_tc_port_fia_max_lane_count(struct intel_digital_port *dig_port);
>
> void intel_tc_port_init(struct intel_digital_port *dig_port, bool is_legacy);
> --
> 2.17.1
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx

--
Ville Syrjälä
Intel