From bc86625a4ff7574d4d4dba79723457711eb784e0 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Sun, 21 Jul 2013 16:00:03 +0100 Subject: [PATCH] drm/i915: Retry DP aux_ch communications with a different clock after failure The w/a db makes the recommendation to both use a non-default value for the initial clock and then to retry with an alternative clock for Haswell with the Lakeport PCH. "On LPT:H, use a divider value of 63 decimal (03Fh). If there is a failure, retry at least three times with 63, then retry at least three times with 72 decimal (048h)." Signed-off-by: Chris Wilson Reviewed-by: Jani Nikula Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_dp.c | 92 ++++++++++++++++++--------------- 1 file changed, 51 insertions(+), 41 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index c6996ced2e5f..4a7ba5ea9ee3 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -276,7 +276,8 @@ intel_dp_aux_wait_done(struct intel_dp *intel_dp, bool has_aux_irq) return status; } -static uint32_t get_aux_clock_divider(struct intel_dp *intel_dp) +static uint32_t get_aux_clock_divider(struct intel_dp *intel_dp, + int index) { struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp); struct drm_device *dev = intel_dig_port->base.base.dev; @@ -290,22 +291,27 @@ static uint32_t get_aux_clock_divider(struct intel_dp *intel_dp) * clock divider. */ if (IS_VALLEYVIEW(dev)) { - return 100; + return index ? 0 : 100; } else if (intel_dig_port->port == PORT_A) { + if (index) + return 0; if (HAS_DDI(dev)) - return DIV_ROUND_CLOSEST( - intel_ddi_get_cdclk_freq(dev_priv), 2000); + return DIV_ROUND_CLOSEST(intel_ddi_get_cdclk_freq(dev_priv), 2000); else if (IS_GEN6(dev) || IS_GEN7(dev)) return 200; /* SNB & IVB eDP input clock at 400Mhz */ else return 225; /* eDP input clock at 450Mhz */ } else if (dev_priv->pch_id == INTEL_PCH_LPT_DEVICE_ID_TYPE) { /* Workaround for non-ULT HSW */ - return 74; + switch (index) { + case 0: return 63; + case 1: return 72; + default: return 0; + } } else if (HAS_PCH_SPLIT(dev)) { - return DIV_ROUND_UP(intel_pch_rawclk(dev), 2); + return index ? 0 : DIV_ROUND_UP(intel_pch_rawclk(dev), 2); } else { - return intel_hrawclk(dev) / 2; + return index ? 0 :intel_hrawclk(dev) / 2; } } @@ -319,10 +325,10 @@ intel_dp_aux_ch(struct intel_dp *intel_dp, struct drm_i915_private *dev_priv = dev->dev_private; uint32_t ch_ctl = intel_dp->aux_ch_ctl_reg; uint32_t ch_data = ch_ctl + 4; + uint32_t aux_clock_divider; int i, ret, recv_bytes; uint32_t status; - uint32_t aux_clock_divider = get_aux_clock_divider(intel_dp); - int try, precharge; + int try, precharge, clock = 0; bool has_aux_irq = INTEL_INFO(dev)->gen >= 5 && !IS_VALLEYVIEW(dev); /* dp aux is extremely sensitive to irq latency, hence request the @@ -353,37 +359,41 @@ intel_dp_aux_ch(struct intel_dp *intel_dp, goto out; } - /* Must try at least 3 times according to DP spec */ - for (try = 0; try < 5; try++) { - /* Load the send data into the aux channel data registers */ - for (i = 0; i < send_bytes; i += 4) - I915_WRITE(ch_data + i, - pack_aux(send + i, send_bytes - i)); - - /* Send the command and wait for it to complete */ - I915_WRITE(ch_ctl, - DP_AUX_CH_CTL_SEND_BUSY | - (has_aux_irq ? DP_AUX_CH_CTL_INTERRUPT : 0) | - DP_AUX_CH_CTL_TIME_OUT_400us | - (send_bytes << DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT) | - (precharge << DP_AUX_CH_CTL_PRECHARGE_2US_SHIFT) | - (aux_clock_divider << DP_AUX_CH_CTL_BIT_CLOCK_2X_SHIFT) | - DP_AUX_CH_CTL_DONE | - DP_AUX_CH_CTL_TIME_OUT_ERROR | - DP_AUX_CH_CTL_RECEIVE_ERROR); - - status = intel_dp_aux_wait_done(intel_dp, has_aux_irq); - - /* Clear done status and any errors */ - I915_WRITE(ch_ctl, - status | - DP_AUX_CH_CTL_DONE | - DP_AUX_CH_CTL_TIME_OUT_ERROR | - DP_AUX_CH_CTL_RECEIVE_ERROR); - - if (status & (DP_AUX_CH_CTL_TIME_OUT_ERROR | - DP_AUX_CH_CTL_RECEIVE_ERROR)) - continue; + while ((aux_clock_divider = get_aux_clock_divider(intel_dp, clock++))) { + /* Must try at least 3 times according to DP spec */ + for (try = 0; try < 5; try++) { + /* Load the send data into the aux channel data registers */ + for (i = 0; i < send_bytes; i += 4) + I915_WRITE(ch_data + i, + pack_aux(send + i, send_bytes - i)); + + /* Send the command and wait for it to complete */ + I915_WRITE(ch_ctl, + DP_AUX_CH_CTL_SEND_BUSY | + (has_aux_irq ? DP_AUX_CH_CTL_INTERRUPT : 0) | + DP_AUX_CH_CTL_TIME_OUT_400us | + (send_bytes << DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT) | + (precharge << DP_AUX_CH_CTL_PRECHARGE_2US_SHIFT) | + (aux_clock_divider << DP_AUX_CH_CTL_BIT_CLOCK_2X_SHIFT) | + DP_AUX_CH_CTL_DONE | + DP_AUX_CH_CTL_TIME_OUT_ERROR | + DP_AUX_CH_CTL_RECEIVE_ERROR); + + status = intel_dp_aux_wait_done(intel_dp, has_aux_irq); + + /* Clear done status and any errors */ + I915_WRITE(ch_ctl, + status | + DP_AUX_CH_CTL_DONE | + DP_AUX_CH_CTL_TIME_OUT_ERROR | + DP_AUX_CH_CTL_RECEIVE_ERROR); + + if (status & (DP_AUX_CH_CTL_TIME_OUT_ERROR | + DP_AUX_CH_CTL_RECEIVE_ERROR)) + continue; + if (status & DP_AUX_CH_CTL_DONE) + break; + } if (status & DP_AUX_CH_CTL_DONE) break; } @@ -1453,7 +1463,7 @@ static void intel_edp_psr_enable_sink(struct intel_dp *intel_dp) { struct drm_device *dev = intel_dp_to_dev(intel_dp); struct drm_i915_private *dev_priv = dev->dev_private; - uint32_t aux_clock_divider = get_aux_clock_divider(intel_dp); + uint32_t aux_clock_divider = get_aux_clock_divider(intel_dp, 0); int precharge = 0x3; int msg_size = 5; /* Header(4) + Message(1) */ -- 2.20.1