[Intel-gfx] [PATCH v6 7/8] drm/i915: BDW clock change support
Jani Nikula
jani.nikula at linux.intel.com
Tue Jun 16 06:07:40 PDT 2015
On Tue, 16 Jun 2015, Jani Nikula <jani.nikula at linux.intel.com> wrote:
> On Wed, 03 Jun 2015, Mika Kahola <mika.kahola at intel.com> wrote:
>> From: Ville Syrjälä <ville.syrjala at 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
>> v4: Rebased to the latest
>> v5: Rebased to the latest
>> v6: Patch order shuffle so that Broadwell CD clock change is
>> applied before the patch for Haswell CD clock change
>> v7: Fix for patch style problems
>>
>> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
>> Signed-off-by: Mika Kahola <mika.kahola at intel.com>
>
> This patch hard hangs my BDW NUC at boot when both DP and HDMI are
> connected. Either DP or HDMI alone are good, same with hotplugging the
> other afterwards. Booting to grub with both connected, and unplugging
> HDMI before loading the kernel also reproduces the issue.
>
> It looks like the problem boils down to the BIOS setting up a smaller
> resolution on the DP display when both are connected, and this patch
> fails to cope with that on i915 load.
By "this patch" I obviously refer to
commit b432e5cfd5e92127ad2dd83bfc3083f1dbce43fb
Author: Ville Syrjälä <ville.syrjala at linux.intel.com>
Date: Wed Jun 3 15:45:13 2015 +0300
drm/i915: BDW clock change support
and everything works for the commit before that.
BR,
Jani.
>
> BR,
> Jani.
>
>
>
>>
>> Author: Ville Syrjälä <ville.syrjala at linux.intel.com>
>> ---
>> drivers/gpu/drm/i915/i915_reg.h | 2 +
>> drivers/gpu/drm/i915/intel_display.c | 216 +++++++++++++++++++++++++++++++++--
>> 2 files changed, 208 insertions(+), 10 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
>> index 7213224..0f72c0e 100644
>> --- a/drivers/gpu/drm/i915/i915_reg.h
>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>> @@ -6705,6 +6705,7 @@ enum skl_disp_power_wells {
>> #define GEN6_PCODE_READ_RC6VIDS 0x5
>> #define GEN6_ENCODE_RC6_VID(mv) (((mv) - 245) / 5)
>> #define GEN6_DECODE_RC6_VID(vids) (((vids) * 5) + 245)
>> +#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
>> @@ -7170,6 +7171,7 @@ enum skl_disp_power_wells {
>> #define LCPLL_CLK_FREQ_337_5_BDW (2<<26)
>> #define LCPLL_CLK_FREQ_675_BDW (3<<26)
>> #define LCPLL_CD_CLOCK_DISABLE (1<<25)
>> +#define LCPLL_ROOT_CD_CLOCK_DISABLE (1<<24)
>> #define LCPLL_CD2X_CLOCK_DISABLE (1<<23)
>> #define LCPLL_POWER_DOWN_ALLOW (1<<22)
>> #define LCPLL_CD_SOURCE_FCLK (1<<21)
>> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
>> index c3f01aa..b1e2069 100644
>> --- a/drivers/gpu/drm/i915/intel_display.c
>> +++ b/drivers/gpu/drm/i915/intel_display.c
>> @@ -5751,7 +5751,22 @@ static void intel_update_max_cdclk(struct drm_device *dev)
>> {
>> struct drm_i915_private *dev_priv = dev->dev_private;
>>
>> - if (IS_VALLEYVIEW(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_VALLEYVIEW(dev)) {
>> dev_priv->max_cdclk_freq = 400000;
>> } else {
>> /* otherwise assume cdclk is fixed */
>> @@ -6621,13 +6636,11 @@ 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;
>> @@ -9608,6 +9621,182 @@ static void broxton_modeset_global_resources(struct drm_atomic_state *old_state)
>> broxton_set_cdclk(dev, req_cdclk);
>> }
>>
>> +/* compute the max rate for new configuration */
>> +static int ilk_max_pixel_rate(struct drm_i915_private *dev_priv)
>> +{
>> + struct drm_device *dev = dev_priv->dev;
>> + struct intel_crtc *intel_crtc;
>> + struct drm_crtc *crtc;
>> + int max_pixel_rate = 0;
>> + int pixel_rate;
>> +
>> + for_each_crtc(dev, crtc) {
>> + if (!crtc->state->enable)
>> + continue;
>> +
>> + intel_crtc = to_intel_crtc(crtc);
>> + pixel_rate = ilk_pipe_pixel_rate(intel_crtc->config);
>> +
>> + /* pixel rate mustn't exceed 95% of cdclk with IPS on BDW */
>> + if (IS_BROADWELL(dev) && intel_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;
>> +}
>> +
>> +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 broadwell_calc_cdclk(struct drm_i915_private *dev_priv,
>> + int max_pixel_rate)
>> +{
>> + int cdclk;
>> +
>> + /*
>> + * FIXME should also account for plane ratio
>> + * once 64bpp pixel formats are supported.
>> + */
>> + if (max_pixel_rate > 540000)
>> + cdclk = 675000;
>> + else if (max_pixel_rate > 450000)
>> + cdclk = 540000;
>> + else if (max_pixel_rate > 337500)
>> + cdclk = 450000;
>> + else
>> + cdclk = 337500;
>> +
>> + /*
>> + * FIXME move the cdclk caclulation to
>> + * compute_config() so we can fail gracegully.
>> + */
>> + if (cdclk > dev_priv->max_cdclk_freq) {
>> + DRM_ERROR("requested cdclk (%d kHz) exceeds max (%d kHz)\n",
>> + cdclk, dev_priv->max_cdclk_freq);
>> + cdclk = dev_priv->max_cdclk_freq;
>> + }
>> +
>> + return cdclk;
>> +}
>> +
>> +static int broadwell_modeset_global_pipes(struct drm_atomic_state *state)
>> +{
>> + struct drm_i915_private *dev_priv = to_i915(state->dev);
>> + struct drm_crtc *crtc;
>> + struct drm_crtc_state *crtc_state;
>> + int max_pixclk = ilk_max_pixel_rate(dev_priv);
>> + int cdclk, i;
>> +
>> + cdclk = broadwell_calc_cdclk(dev_priv, max_pixclk);
>> +
>> + if (cdclk == dev_priv->cdclk_freq)
>> + return 0;
>> +
>> + /* add all active pipes to the state */
>> + for_each_crtc(state->dev, crtc) {
>> + if (!crtc->state->enable)
>> + continue;
>> +
>> + crtc_state = drm_atomic_get_crtc_state(state, crtc);
>> + if (IS_ERR(crtc_state))
>> + return PTR_ERR(crtc_state);
>> + }
>> +
>> + /* disable/enable all currently active pipes while we change cdclk */
>> + for_each_crtc_in_state(state, crtc, crtc_state, i)
>> + if (crtc_state->enable)
>> + crtc_state->mode_changed = true;
>> +
>> + return 0;
>> +}
>> +
>> +static void broadwell_modeset_global_resources(struct drm_atomic_state *state)
>> +{
>> + struct drm_device *dev = state->dev;
>> + struct drm_i915_private *dev_priv = dev->dev_private;
>> + int max_pixel_rate = ilk_max_pixel_rate(dev_priv);
>> + int req_cdclk = broadwell_calc_cdclk(dev_priv, max_pixel_rate);
>> +
>> + if (req_cdclk != dev_priv->cdclk_freq)
>> + broadwell_set_cdclk(dev, req_cdclk);
>> +}
>> +
>> static int haswell_crtc_compute_clock(struct intel_crtc *crtc,
>> struct intel_crtc_state *crtc_state)
>> {
>> @@ -12788,8 +12977,12 @@ 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)) {
>> - ret = valleyview_modeset_global_pipes(state);
>> + if (IS_VALLEYVIEW(dev) || IS_BROXTON(dev) || IS_BROADWELL(dev)) {
>> + if (IS_VALLEYVIEW(dev) || IS_BROXTON(dev))
>> + ret = valleyview_modeset_global_pipes(state);
>> + else
>> + ret = broadwell_modeset_global_pipes(state);
>> +
>> if (ret)
>> return ret;
>> }
>> @@ -14677,6 +14870,9 @@ 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_BROADWELL(dev))
>> + dev_priv->display.modeset_global_resources =
>> + broadwell_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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>> Intel-gfx at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
> --
> Jani Nikula, Intel Open Source Technology Center
--
Jani Nikula, Intel Open Source Technology Center
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