On Fri, May 22, 2015 at 11:22:42AM +0300, Mika Kahola wrote:
> From: Ville Syrjälä <ville.syrj...@linux.intel.com>
>
> Add support for changing cdclk frequency during runtime on BDW. The
> procedure is quite a bit different on BDW from the one on HSW, so
> add a separate function for it.
>
> Also with IPS enabled the actual pixel rate mustn't exceed 95% of cdclk,
> so take that into account when computing the max pixel rate.
>
> v2: Grab rps.hw_lock around sandybridge_pcode_write()
> v3: Rebase due to power well vs. .global_resources() reordering
>
> Signed-off-by: Ville Syrjälä <ville.syrj...@linux.intel.com>
>
> v4: Rebased to the latest
> v5: Rebased to the latest
>
> Reviewed-by: Mika Kahola <mika.kah...@intel.com>
>
> Author: Ville Syrjälä <ville.syrj...@linux.intel.com>
> ---
(fwiw, I'm making the SKL cdclk code look like those HSW/BDW patches a
bit more. We may want to extract a few low level vfuncs
(set_core_display_clock(), ...) but that's for another time)
Reviewed-by: Damien Lespiau <damien.lesp...@intel.com>
> drivers/gpu/drm/i915/i915_reg.h | 1 +
> drivers/gpu/drm/i915/intel_display.c | 139
> ++++++++++++++++++++++++++++++-----
> 2 files changed, 122 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 015fe12..64ec500 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -6702,6 +6702,7 @@ enum skl_disp_power_wells {
> #define GEN6_ENCODE_RC6_VID(mv) (((mv) - 245) / 5)
> #define GEN6_DECODE_RC6_VID(vids) (((vids) * 5) + 245)
> #define HSW_PCODE_DE_WRITE_FREQ_REQ 0x17
> +#define BDW_PCODE_DISPLAY_FREQ_CHANGE_REQ 0x18
> #define GEN9_PCODE_READ_MEM_LATENCY 0x6
> #define GEN9_MEM_LATENCY_LEVEL_MASK 0xFF
> #define GEN9_MEM_LATENCY_LEVEL_1_5_SHIFT 8
> diff --git a/drivers/gpu/drm/i915/intel_display.c
> b/drivers/gpu/drm/i915/intel_display.c
> index 556d0ec7..71efd2f 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -5545,7 +5545,22 @@ static void intel_update_max_cdclk(struct drm_device
> *dev)
> {
> struct drm_i915_private *dev_priv = dev->dev_private;
>
> - if (IS_HASWELL(dev)) {
> + if (IS_BROADWELL(dev)) {
> + /*
> + * FIXME with extra cooling we can allow
> + * 540 MHz for ULX and 675 Mhz for ULT.
> + * How can we know if extra cooling is
> + * available? PCI ID, VTB, something else?
> + */
> + if (I915_READ(FUSE_STRAP) & HSW_CDCLK_LIMIT)
> + dev_priv->max_cdclk_freq = 450000;
> + else if (IS_BDW_ULX(dev))
> + dev_priv->max_cdclk_freq = 450000;
> + else if (IS_BDW_ULT(dev))
> + dev_priv->max_cdclk_freq = 540000;
> + else
> + dev_priv->max_cdclk_freq = 675000;
> + } else if (IS_HASWELL(dev)) {
> if (I915_READ(FUSE_STRAP) & HSW_CDCLK_LIMIT)
> dev_priv->max_cdclk_freq = 450000;
> else if (IS_HSW_ULX(dev))
> @@ -6426,13 +6441,11 @@ static bool pipe_config_supports_ips(struct
> drm_i915_private *dev_priv,
> return true;
>
> /*
> - * FIXME if we compare against max we should then
> - * increase the cdclk frequency when the current
> - * value is too low. The other option is to compare
> - * against the cdclk frequency we're going have post
> - * modeset (ie. one we computed using other constraints).
> - * Need to measure whether using a lower cdclk w/o IPS
> - * is better or worse than a higher cdclk w/ IPS.
> + * We compare against max which means we must take
> + * the increased cdclk requirement into account when
> + * calculating the new cdclk.
> + *
> + * Should measure whether using a lower cdclk w/o IPS
> */
> return ilk_pipe_pixel_rate(pipe_config) <=
> dev_priv->max_cdclk_freq * 95 / 100;
> @@ -9421,9 +9434,18 @@ static int ilk_max_pixel_rate(struct drm_i915_private
> *dev_priv)
> int max_pixel_rate = 0;
>
> for_each_intel_crtc(dev, crtc) {
> - if (crtc->new_enabled)
> - max_pixel_rate = max((int)max_pixel_rate,
> -
> (int)ilk_pipe_pixel_rate(crtc->config));
> + int pixel_rate;
> +
> + if (!crtc->new_enabled)
> + continue;
> +
> + pixel_rate = ilk_pipe_pixel_rate(crtc->config);
> +
> + /* pixel rate mustn't exceed 95% of cdclk with IPS on BDW */
> + if (IS_BROADWELL(dev) && crtc->config->ips_enabled)
> + pixel_rate = DIV_ROUND_UP(pixel_rate * 100, 95);
> +
> + max_pixel_rate = max(max_pixel_rate, pixel_rate);
> }
>
> return max_pixel_rate;
> @@ -9438,7 +9460,9 @@ static int haswell_calc_cdclk(struct drm_i915_private
> *dev_priv,
> * FIXME should also account for plane ratio
> * once 64bpp pixel formats are supported.
> */
> - if (max_pixel_rate > 450000)
> + if (max_pixel_rate > 540000)
> + cdclk = 675000;
> + else if (max_pixel_rate > 450000)
> cdclk = 540000;
> else if (max_pixel_rate > 337500 || !IS_HSW_ULX(dev_priv))
> cdclk = 450000;
> @@ -9503,6 +9527,83 @@ static void haswell_set_cdclk(struct drm_device *dev,
> int cdclk)
> cdclk, dev_priv->cdclk_freq);
> }
Quite frankly, I'd split out a broadwell cacl_cdclk out.
>
> +static void broadwell_set_cdclk(struct drm_device *dev, int cdclk)
> +{
> + struct drm_i915_private *dev_priv = dev->dev_private;
> + uint32_t val, data;
> + int ret;
> +
> + if (WARN((I915_READ(LCPLL_CTL) &
> + (LCPLL_PLL_DISABLE | LCPLL_PLL_LOCK |
> + LCPLL_CD_CLOCK_DISABLE | LCPLL_ROOT_CD_CLOCK_DISABLE |
> + LCPLL_CD2X_CLOCK_DISABLE | LCPLL_POWER_DOWN_ALLOW |
> + LCPLL_CD_SOURCE_FCLK)) != LCPLL_PLL_LOCK,
> + "trying to change cdclk frequency with cdclk not enabled\n"))
> + return;
> +
> + mutex_lock(&dev_priv->rps.hw_lock);
> + ret = sandybridge_pcode_write(dev_priv,
> + BDW_PCODE_DISPLAY_FREQ_CHANGE_REQ, 0x0);
> + mutex_unlock(&dev_priv->rps.hw_lock);
> + if (ret) {
> + DRM_ERROR("failed to inform pcode about cdclk change\n");
> + return;
> + }
> +
> + val = I915_READ(LCPLL_CTL);
> + val |= LCPLL_CD_SOURCE_FCLK;
> + I915_WRITE(LCPLL_CTL, val);
> +
> + if (wait_for_atomic_us(I915_READ(LCPLL_CTL) &
> + LCPLL_CD_SOURCE_FCLK_DONE, 1))
> + DRM_ERROR("Switching to FCLK failed\n");
> +
> + val = I915_READ(LCPLL_CTL);
> + val &= ~LCPLL_CLK_FREQ_MASK;
> +
> + switch (cdclk) {
> + case 450000:
> + val |= LCPLL_CLK_FREQ_450;
> + data = 0;
> + break;
> + case 540000:
> + val |= LCPLL_CLK_FREQ_54O_BDW;
> + data = 1;
> + break;
> + case 337500:
> + val |= LCPLL_CLK_FREQ_337_5_BDW;
> + data = 2;
> + break;
> + case 675000:
> + val |= LCPLL_CLK_FREQ_675_BDW;
> + data = 3;
> + break;
> + default:
> + WARN(1, "invalid cdclk frequency\n");
> + return;
> + }
> +
> + I915_WRITE(LCPLL_CTL, val);
> +
> + val = I915_READ(LCPLL_CTL);
> + val &= ~LCPLL_CD_SOURCE_FCLK;
> + I915_WRITE(LCPLL_CTL, val);
> +
> + if (wait_for_atomic_us((I915_READ(LCPLL_CTL) &
> + LCPLL_CD_SOURCE_FCLK_DONE) == 0, 1))
> + DRM_ERROR("Switching back to LCPLL failed\n");
> +
> + mutex_lock(&dev_priv->rps.hw_lock);
> + sandybridge_pcode_write(dev_priv, HSW_PCODE_DE_WRITE_FREQ_REQ, data);
> + mutex_unlock(&dev_priv->rps.hw_lock);
> +
> + intel_update_cdclk(dev);
> +
> + WARN(cdclk != dev_priv->cdclk_freq,
> + "cdclk requested %d kHz but got %d kHz\n",
> + cdclk, dev_priv->cdclk_freq);
> +}
> +
> static int haswell_modeset_global_pipes(struct drm_atomic_state *state)
> {
> struct drm_i915_private *dev_priv = to_i915(state->dev);
> @@ -9542,7 +9643,10 @@ static void haswell_modeset_global_resources(struct
> drm_atomic_state *state)
> int req_cdclk = haswell_calc_cdclk(dev_priv, max_pixel_rate);
>
> if (req_cdclk != dev_priv->cdclk_freq) {
> - haswell_set_cdclk(dev, req_cdclk);
> + if (IS_BROADWELL(dev))
> + broadwell_set_cdclk(dev, req_cdclk);
> + else
> + haswell_set_cdclk(dev, req_cdclk);
> }
> }
>
> @@ -12724,8 +12828,8 @@ static int __intel_set_mode_checks(struct
> drm_atomic_state *state)
> * mode set on this crtc. For other crtcs we need to use the
> * adjusted_mode bits in the crtc directly.
> */
> - if (IS_VALLEYVIEW(dev) || IS_BROXTON(dev) || IS_HASWELL(dev)) {
> - if (IS_VALLEYVIEW(dev) || IS_BROXTON(dev)) {
> + if (IS_VALLEYVIEW(dev) || IS_BROXTON(dev) || IS_HASWELL(dev) ||
> IS_BROADWELL(dev)) {
> + if (IS_VALLEYVIEW(dev) || IS_BROXTON(dev) || IS_BROADWELL(dev))
> {
> ret = valleyview_modeset_global_pipes(state);
> if (ret)
> return ret;
> @@ -14616,9 +14720,8 @@ static void intel_init_display(struct drm_device *dev)
> dev_priv->display.fdi_link_train = ivb_manual_fdi_link_train;
> } else if (IS_HASWELL(dev) || IS_BROADWELL(dev)) {
> dev_priv->display.fdi_link_train = hsw_fdi_link_train;
> - if (IS_HASWELL(dev))
> - dev_priv->display.modeset_global_resources =
> - haswell_modeset_global_resources;
> + dev_priv->display.modeset_global_resources =
> + haswell_modeset_global_resources;
> } else if (IS_VALLEYVIEW(dev)) {
> dev_priv->display.modeset_global_resources =
> valleyview_modeset_global_resources;
> --
> 1.9.1
>
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