On Sun, 21 Jul 2013, Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote:
> 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)."
Overall I'd prefer adding the outer repeat loop first, keeping existing
behaviour, and only then adding the divider value changes in
get_aux_clock_divider(). But that's in the bikeshedding dept. Either
way,
Reviewed-by: Jani Nikula <jani.nikula@xxxxxxxxx>
> Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
> ---
> 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 c6996ce..4a7ba5e 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) */
>
> --
> 1.8.3.2
>
> _______________________________________________
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> Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
--
Jani Nikula, Intel Open Source Technology Center
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