From e828da3028b06cba43d4d91b94cb884d8927be09 Mon Sep 17 00:00:00 2001 From: Manasi Navare Date: Wed, 1 Jul 2020 15:10:52 -0700 Subject: [PATCH] drm/i915/dp: Helper to check for DDI BUF status to get active MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Based on the platform, Bspec expects us to wait or poll with timeout for DDI BUF IDLE bit to be set to 0 (non idle) or get active after enabling DDI_BUF_CTL. v2: * Based on platform, fixed delay or poll (Ville) * Use a helper to do this (Imre, Ville) v3: * Add a new function _active for DDI BUF CTL to be non idle (Ville) v4: * Use the timeout for GLK (Ville) v5: * Add bspec quote, change timeout to 500us (Ville) Cc: Ville Syrjälä Cc: Imre Deak Signed-off-by: Manasi Navare Reviewed-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20200701221052.8946-2-manasi.d.navare@intel.com --- drivers/gpu/drm/i915/display/intel_ddi.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c index 2120d6da3fcc5..5773ebefffc74 100644 --- a/drivers/gpu/drm/i915/display/intel_ddi.c +++ b/drivers/gpu/drm/i915/display/intel_ddi.c @@ -1195,6 +1195,21 @@ static void intel_wait_ddi_buf_idle(struct drm_i915_private *dev_priv, port_name(port)); } +static void intel_wait_ddi_buf_active(struct drm_i915_private *dev_priv, + enum port port) +{ + /* Wait > 518 usecs for DDI_BUF_CTL to be non idle */ + if (INTEL_GEN(dev_priv) < 10 && !IS_GEMINILAKE(dev_priv)) { + usleep_range(518, 1000); + return; + } + + if (wait_for_us(!(intel_de_read(dev_priv, DDI_BUF_CTL(port)) & + DDI_BUF_IS_IDLE), 500)) + drm_err(&dev_priv->drm, "Timeout waiting for DDI BUF %c to get active\n", + port_name(port)); +} + static u32 hsw_pll_to_ddi_pll_sel(const struct intel_shared_dpll *pll) { switch (pll->info->id) { @@ -4017,7 +4032,7 @@ static void intel_ddi_prepare_link_retrain(struct intel_dp *intel_dp) intel_de_write(dev_priv, DDI_BUF_CTL(port), intel_dp->DP); intel_de_posting_read(dev_priv, DDI_BUF_CTL(port)); - udelay(600); + intel_wait_ddi_buf_active(dev_priv, port); } static void intel_ddi_set_link_train(struct intel_dp *intel_dp, -- 2.30.2