[Intel-gfx] [PATCH] Revert "drm/i915/skl: New ddb allocation algorithm"

Rodrigo Vivi rodrigo.vivi at gmail.com
Tue Jun 13 19:06:05 UTC 2017


On Tue, Jun 13, 2017 at 11:07 AM, Matt Roper <matthew.d.roper at intel.com> wrote:
> On Tue, Jun 13, 2017 at 10:52:30AM -0700, Rodrigo Vivi wrote:
>> This reverts commit bb9d85f6e9de8fef5236c076530eab67a2f2431b.
>>
>> New ddb allocation algorithm is a show stopper on my SKL system.
>>
>> Besides not be able to get external DP 4k at 60 (through USB type C),
>> It fully hang my screen when unplugging the USB type C.
>>
>> Cc: Mahesh Kumar <mahesh1.kumar at intel.com>
>> Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
>> Cc: Matt Roper <matthew.d.roper at intel.com>
>> Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
>
> Is there a bugzilla entry with details/logs from the failure we can
> refer to?

nope, since I know it was working few weeks ago and then stopped
working I went directly
to bisect so I could get my system usable quickly again.

But yes, I need to open a proper bugzilla and provide logs.
Should we revert first and grab logs latter or we are going to try to
analyse logs and fix?

Anyways this is a big show stopper so I believe we revert at least
before next pull request.

When you say you can't get DP 4k at 60, are you seeing messages
> in dmesg about the setup being outside system watermark limitations or
> are you just getting a black screen?

just getting a blank screen on DP when plugging usb-c and a locked-up
screen on eDP when removing usb-c.

>
>
> Matt
>
>> ---
>>  drivers/gpu/drm/i915/intel_pm.c | 257 +++++++++++++++-------------------------
>>  1 file changed, 98 insertions(+), 159 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
>> index aa9d8ce..dc4275d 100644
>> --- a/drivers/gpu/drm/i915/intel_pm.c
>> +++ b/drivers/gpu/drm/i915/intel_pm.c
>> @@ -4140,41 +4140,13 @@ int skl_check_pipe_max_pixel_rate(struct intel_crtc *intel_crtc,
>>       minimum[PLANE_CURSOR] = skl_cursor_allocation(num_active);
>>  }
>>
>> -static void
>> -skl_enable_plane_wm_levels(const struct drm_i915_private *dev_priv,
>> -                        uint16_t plane_ddb,
>> -                        uint16_t max_level,
>> -                        struct skl_plane_wm *wm)
>> -{
>> -     int level;
>> -     /*
>> -      * Now enable all levels in WM structure which can be enabled
>> -      * using current DDB allocation
>> -      */
>> -     for (level = ilk_wm_max_level(dev_priv); level >= 0; level--) {
>> -             struct skl_wm_level *level_wm = &wm->wm[level];
>> -
>> -             if (level > max_level || level_wm->plane_res_b == 0
>> -                                   || level_wm->plane_res_l >= 31
>> -                                   || level_wm->plane_res_b >= plane_ddb) {
>> -                     level_wm->plane_en = false;
>> -                     level_wm->plane_res_b = 0;
>> -                     level_wm->plane_res_l = 0;
>> -             } else {
>> -                     level_wm->plane_en = true;
>> -             }
>> -     }
>> -}
>> -
>>  static int
>>  skl_allocate_pipe_ddb(struct intel_crtc_state *cstate,
>> -                   struct skl_pipe_wm *pipe_wm,
>>                     struct skl_ddb_allocation *ddb /* out */)
>>  {
>>       struct drm_atomic_state *state = cstate->base.state;
>>       struct drm_crtc *crtc = cstate->base.crtc;
>>       struct drm_device *dev = crtc->dev;
>> -     struct drm_i915_private *dev_priv = to_i915(dev);
>>       struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
>>       enum pipe pipe = intel_crtc->pipe;
>>       struct skl_ddb_entry *alloc = &cstate->wm.skl.ddb;
>> @@ -4187,9 +4159,6 @@ int skl_check_pipe_max_pixel_rate(struct intel_crtc *intel_crtc,
>>       unsigned plane_data_rate[I915_MAX_PLANES] = {};
>>       unsigned plane_y_data_rate[I915_MAX_PLANES] = {};
>>       uint16_t total_min_blocks = 0;
>> -     uint16_t total_level_ddb;
>> -     uint16_t plane_blocks = 0;
>> -     int max_level, level;
>>
>>       /* Clear the partitioning for disabled planes. */
>>       memset(ddb->plane[pipe], 0, sizeof(ddb->plane[pipe]));
>> @@ -4228,48 +4197,10 @@ int skl_check_pipe_max_pixel_rate(struct intel_crtc *intel_crtc,
>>               return -EINVAL;
>>       }
>>
>> -     alloc_size -= minimum[PLANE_CURSOR];
>> -     ddb->plane[pipe][PLANE_CURSOR].start = alloc->end -
>> -                                                     minimum[PLANE_CURSOR];
>> +     alloc_size -= total_min_blocks;
>> +     ddb->plane[pipe][PLANE_CURSOR].start = alloc->end - minimum[PLANE_CURSOR];
>>       ddb->plane[pipe][PLANE_CURSOR].end = alloc->end;
>>
>> -     for (level = ilk_wm_max_level(dev_priv); level >= 0; level--) {
>> -             total_level_ddb = 0;
>> -             for_each_plane_id_on_crtc(intel_crtc, plane_id) {
>> -                     /*
>> -                      * TODO: We should calculate watermark values for Y/UV
>> -                      * plane both in case of NV12 format and use both values
>> -                      * for ddb calculation. NV12 is disabled as of now, So
>> -                      * using only single/UV plane value here.
>> -                      */
>> -                     struct skl_plane_wm *wm = &pipe_wm->planes[plane_id];
>> -                     uint16_t plane_res_b = wm->wm[level].plane_res_b;
>> -                     uint16_t min = minimum[plane_id] + y_minimum[plane_id];
>> -
>> -                     if (plane_id == PLANE_CURSOR)
>> -                             continue;
>> -
>> -                     total_level_ddb += max(plane_res_b, min);
>> -             }
>> -
>> -             /*
>> -              * If This level can successfully be enabled with the
>> -              * pipe's current DDB allocation, then all lower levels are
>> -              * guaranteed to succeed as well.
>> -              */
>> -             if (total_level_ddb <= alloc_size)
>> -                     break;
>> -     }
>> -
>> -     if ((level < 0) || (total_min_blocks > alloc_size)) {
>> -             DRM_DEBUG_KMS("Requested display configuration exceeds system DDB limitations");
>> -             DRM_DEBUG_KMS("minimum required %d/%d\n", (level < 0) ?
>> -                             total_level_ddb : total_min_blocks, alloc_size);
>> -             return -EINVAL;
>> -     }
>> -     max_level = level;
>> -     alloc_size -= total_level_ddb;
>> -
>>       /*
>>        * 2. Distribute the remaining space in proportion to the amount of
>>        * data each plane needs to fetch from memory.
>> @@ -4279,24 +4210,13 @@ int skl_check_pipe_max_pixel_rate(struct intel_crtc *intel_crtc,
>>       total_data_rate = skl_get_total_relative_data_rate(cstate,
>>                                                          plane_data_rate,
>>                                                          plane_y_data_rate);
>> -     /*
>> -      * PLANE_CURSOR data rate is not included in total_data_rate.
>> -      * If only cursor plane is enabled we have to enable its WM levels
>> -      * explicitly before returning. Cursor has fixed ddb allocation,
>> -      * So it's ok to always check cursor WM enabling before return.
>> -      */
>> -     plane_blocks = skl_ddb_entry_size(&ddb->plane[pipe][PLANE_CURSOR]);
>> -     skl_enable_plane_wm_levels(dev_priv, plane_blocks, max_level,
>> -                                &pipe_wm->planes[PLANE_CURSOR]);
>>       if (total_data_rate == 0)
>>               return 0;
>>
>>       start = alloc->start;
>>       for_each_plane_id_on_crtc(intel_crtc, plane_id) {
>>               unsigned int data_rate, y_data_rate;
>> -             uint16_t plane_blocks = 0, y_plane_blocks = 0;
>> -             struct skl_plane_wm *wm = &pipe_wm->planes[plane_id];
>> -             uint16_t plane_res_b = wm->wm[max_level].plane_res_b;
>> +             uint16_t plane_blocks, y_plane_blocks = 0;
>>
>>               if (plane_id == PLANE_CURSOR)
>>                       continue;
>> @@ -4308,36 +4228,33 @@ int skl_check_pipe_max_pixel_rate(struct intel_crtc *intel_crtc,
>>                * promote the expression to 64 bits to avoid overflowing, the
>>                * result is < available as data_rate / total_data_rate < 1
>>                */
>> +             plane_blocks = minimum[plane_id];
>> +             plane_blocks += div_u64((uint64_t)alloc_size * data_rate,
>> +                                     total_data_rate);
>>
>>               /* Leave disabled planes at (0,0) */
>>               if (data_rate) {
>> -                     plane_blocks = max(minimum[plane_id], plane_res_b);
>> -                     plane_blocks += div_u64((uint64_t)alloc_size *
>> -                                     data_rate, total_data_rate);
>>                       ddb->plane[pipe][plane_id].start = start;
>>                       ddb->plane[pipe][plane_id].end = start + plane_blocks;
>> -                     start += plane_blocks;
>>               }
>>
>> +             start += plane_blocks;
>> +
>>               /*
>>                * allocation for y_plane part of planar format:
>> -              * TODO: Once we start calculating watermark values for Y/UV
>> -              * plane both consider it for initial allowed wm blocks.
>>                */
>>               y_data_rate = plane_y_data_rate[plane_id];
>>
>> +             y_plane_blocks = y_minimum[plane_id];
>> +             y_plane_blocks += div_u64((uint64_t)alloc_size * y_data_rate,
>> +                                     total_data_rate);
>> +
>>               if (y_data_rate) {
>> -                     y_plane_blocks = y_minimum[plane_id];
>> -                     y_plane_blocks += div_u64((uint64_t)alloc_size *
>> -                                     y_data_rate, total_data_rate);
>>                       ddb->y_plane[pipe][plane_id].start = start;
>>                       ddb->y_plane[pipe][plane_id].end = start + y_plane_blocks;
>> -                     start += y_plane_blocks;
>>               }
>> -             skl_enable_plane_wm_levels(dev_priv,
>> -                                        plane_blocks,
>> -                                        max_level,
>> -                                        wm);
>> +
>> +             start += y_plane_blocks;
>>       }
>>
>>       return 0;
>> @@ -4427,9 +4344,11 @@ static uint_fixed_16_16_t skl_wm_method2(uint32_t pixel_rate,
>>  static int skl_compute_plane_wm(const struct drm_i915_private *dev_priv,
>>                               struct intel_crtc_state *cstate,
>>                               const struct intel_plane_state *intel_pstate,
>> +                             uint16_t ddb_allocation,
>>                               int level,
>>                               uint16_t *out_blocks, /* out */
>> -                             uint8_t *out_lines /* out */)
>> +                             uint8_t *out_lines, /* out */
>> +                             bool *enabled /* out */)
>>  {
>>       struct intel_plane *plane = to_intel_plane(intel_pstate->base.plane);
>>       const struct drm_plane_state *pstate = &intel_pstate->base;
>> @@ -4452,8 +4371,10 @@ static int skl_compute_plane_wm(const struct drm_i915_private *dev_priv,
>>       bool y_tiled, x_tiled;
>>
>>       if (latency == 0 ||
>> -         !intel_wm_plane_visible(cstate, intel_pstate))
>> +         !intel_wm_plane_visible(cstate, intel_pstate)) {
>> +             *enabled = false;
>>               return 0;
>> +     }
>>
>>       y_tiled = fb->modifier == I915_FORMAT_MOD_Y_TILED ||
>>                 fb->modifier == I915_FORMAT_MOD_Yf_TILED;
>> @@ -4541,6 +4462,9 @@ static int skl_compute_plane_wm(const struct drm_i915_private *dev_priv,
>>               if ((cpp * cstate->base.adjusted_mode.crtc_htotal / 512 < 1) &&
>>                   (plane_bytes_per_line / 512 < 1))
>>                       selected_result = method2;
>> +             else if ((ddb_allocation && ddb_allocation /
>> +                     fixed_16_16_to_u32_round_up(plane_blocks_per_line)) >= 1)
>> +                     selected_result = min_fixed_16_16(method1, method2);
>>               else if (latency >= linetime_us)
>>                       selected_result = min_fixed_16_16(method1, method2);
>>               else
>> @@ -4560,42 +4484,64 @@ static int skl_compute_plane_wm(const struct drm_i915_private *dev_priv,
>>               }
>>       }
>>
>> -     if (res_lines >= 31 && level == 0) {
>> -             struct drm_plane *plane = pstate->plane;
>> +     if (res_blocks >= ddb_allocation || res_lines > 31) {
>> +             *enabled = false;
>>
>> -             DRM_DEBUG_KMS("Requested display configuration exceeds system watermark limitations\n");
>> -             DRM_DEBUG_KMS("[PLANE:%d:%s] lines required = %u/31\n",
>> -                             plane->base.id, plane->name, res_lines);
>> -             return -EINVAL;
>> +             /*
>> +              * If there are no valid level 0 watermarks, then we can't
>> +              * support this display configuration.
>> +              */
>> +             if (level) {
>> +                     return 0;
>> +             } else {
>> +                     struct drm_plane *plane = pstate->plane;
>> +
>> +                     DRM_DEBUG_KMS("Requested display configuration exceeds system watermark limitations\n");
>> +                     DRM_DEBUG_KMS("[PLANE:%d:%s] blocks required = %u/%u, lines required = %u/31\n",
>> +                                   plane->base.id, plane->name,
>> +                                   res_blocks, ddb_allocation, res_lines);
>> +                     return -EINVAL;
>> +             }
>>       }
>>
>>       *out_blocks = res_blocks;
>>       *out_lines = res_lines;
>> +     *enabled = true;
>>
>>       return 0;
>>  }
>>
>>  static int
>>  skl_compute_wm_levels(const struct drm_i915_private *dev_priv,
>> +                   struct skl_ddb_allocation *ddb,
>>                     struct intel_crtc_state *cstate,
>>                     const struct intel_plane_state *intel_pstate,
>>                     struct skl_plane_wm *wm)
>>  {
>> +     struct intel_crtc *intel_crtc = to_intel_crtc(cstate->base.crtc);
>> +     struct drm_plane *plane = intel_pstate->base.plane;
>> +     struct intel_plane *intel_plane = to_intel_plane(plane);
>> +     uint16_t ddb_blocks;
>> +     enum pipe pipe = intel_crtc->pipe;
>>       int level, max_level = ilk_wm_max_level(dev_priv);
>>       int ret;
>>
>>       if (WARN_ON(!intel_pstate->base.fb))
>>               return -EINVAL;
>>
>> +     ddb_blocks = skl_ddb_entry_size(&ddb->plane[pipe][intel_plane->id]);
>> +
>>       for (level = 0; level <= max_level; level++) {
>>               struct skl_wm_level *result = &wm->wm[level];
>>
>>               ret = skl_compute_plane_wm(dev_priv,
>>                                          cstate,
>>                                          intel_pstate,
>> +                                        ddb_blocks,
>>                                          level,
>>                                          &result->plane_res_b,
>> -                                        &result->plane_res_l);
>> +                                        &result->plane_res_l,
>> +                                        &result->plane_en);
>>               if (ret)
>>                       return ret;
>>       }
>> @@ -4661,7 +4607,8 @@ static int skl_build_pipe_wm(struct intel_crtc_state *cstate,
>>
>>               wm = &pipe_wm->planes[plane_id];
>>
>> -             ret = skl_compute_wm_levels(dev_priv, cstate, intel_pstate, wm);
>> +             ret = skl_compute_wm_levels(dev_priv, ddb, cstate,
>> +                                         intel_pstate, wm);
>>               if (ret)
>>                       return ret;
>>               skl_compute_transition_wm(cstate, &wm->trans_wm);
>> @@ -4774,45 +4721,6 @@ bool skl_ddb_allocation_overlaps(const struct skl_ddb_entry **entries,
>>       return false;
>>  }
>>
>> -static int
>> -skl_ddb_add_affected_planes(struct intel_crtc_state *cstate,
>> -                         const struct skl_pipe_wm *old_pipe_wm,
>> -                         const struct skl_pipe_wm *pipe_wm)
>> -{
>> -     struct drm_atomic_state *state = cstate->base.state;
>> -     struct drm_device *dev = state->dev;
>> -     struct drm_crtc *crtc = cstate->base.crtc;
>> -     struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
>> -     struct drm_i915_private *dev_priv = to_i915(dev);
>> -     struct intel_atomic_state *intel_state = to_intel_atomic_state(state);
>> -     struct skl_ddb_allocation *new_ddb = &intel_state->wm_results.ddb;
>> -     struct skl_ddb_allocation *cur_ddb = &dev_priv->wm.skl_hw.ddb;
>> -     struct drm_plane_state *plane_state;
>> -     struct drm_plane *plane;
>> -     enum pipe pipe = intel_crtc->pipe;
>> -
>> -     WARN_ON(!drm_atomic_get_existing_crtc_state(state, crtc));
>> -
>> -     drm_for_each_plane_mask(plane, dev, cstate->base.plane_mask) {
>> -             enum plane_id plane_id = to_intel_plane(plane)->id;
>> -             const struct skl_plane_wm *wm = &pipe_wm->planes[plane_id];
>> -             const struct skl_plane_wm *old_wm = &old_pipe_wm->planes[plane_id];
>> -
>> -             if ((skl_ddb_entry_equal(&cur_ddb->plane[pipe][plane_id],
>> -                                     &new_ddb->plane[pipe][plane_id]) &&
>> -                 skl_ddb_entry_equal(&cur_ddb->y_plane[pipe][plane_id],
>> -                                     &new_ddb->y_plane[pipe][plane_id])) &&
>> -                 !memcmp(wm, old_wm, sizeof(struct skl_plane_wm)))
>> -                     continue;
>> -
>> -             plane_state = drm_atomic_get_plane_state(state, plane);
>> -             if (IS_ERR(plane_state))
>> -                     return PTR_ERR(plane_state);
>> -     }
>> -
>> -     return 0;
>> -}
>> -
>>  static int skl_update_pipe_wm(struct drm_crtc_state *cstate,
>>                             const struct skl_pipe_wm *old_pipe_wm,
>>                             struct skl_pipe_wm *pipe_wm, /* out */
>> @@ -4826,17 +4734,6 @@ static int skl_update_pipe_wm(struct drm_crtc_state *cstate,
>>       if (ret)
>>               return ret;
>>
>> -     ret = skl_allocate_pipe_ddb(intel_cstate, pipe_wm, ddb);
>> -     if (ret)
>> -             return ret;
>> -     /*
>> -      * TODO: Planes are included in state to arm WM registers.
>> -      * Scope to optimize further, by just rewriting plane surf register.
>> -      */
>> -     ret = skl_ddb_add_affected_planes(intel_cstate, old_pipe_wm, pipe_wm);
>> -     if (ret)
>> -             return ret;
>> -
>>       if (!memcmp(old_pipe_wm, pipe_wm, sizeof(*pipe_wm)))
>>               *changed = false;
>>       else
>> @@ -4859,7 +4756,41 @@ static int skl_update_pipe_wm(struct drm_crtc_state *cstate,
>>  }
>>
>>  static int
>> -skl_include_affected_crtcs(struct drm_atomic_state *state)
>> +skl_ddb_add_affected_planes(struct intel_crtc_state *cstate)
>> +{
>> +     struct drm_atomic_state *state = cstate->base.state;
>> +     struct drm_device *dev = state->dev;
>> +     struct drm_crtc *crtc = cstate->base.crtc;
>> +     struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
>> +     struct drm_i915_private *dev_priv = to_i915(dev);
>> +     struct intel_atomic_state *intel_state = to_intel_atomic_state(state);
>> +     struct skl_ddb_allocation *new_ddb = &intel_state->wm_results.ddb;
>> +     struct skl_ddb_allocation *cur_ddb = &dev_priv->wm.skl_hw.ddb;
>> +     struct drm_plane_state *plane_state;
>> +     struct drm_plane *plane;
>> +     enum pipe pipe = intel_crtc->pipe;
>> +
>> +     WARN_ON(!drm_atomic_get_existing_crtc_state(state, crtc));
>> +
>> +     drm_for_each_plane_mask(plane, dev, cstate->base.plane_mask) {
>> +             enum plane_id plane_id = to_intel_plane(plane)->id;
>> +
>> +             if (skl_ddb_entry_equal(&cur_ddb->plane[pipe][plane_id],
>> +                                     &new_ddb->plane[pipe][plane_id]) &&
>> +                 skl_ddb_entry_equal(&cur_ddb->y_plane[pipe][plane_id],
>> +                                     &new_ddb->y_plane[pipe][plane_id]))
>> +                     continue;
>> +
>> +             plane_state = drm_atomic_get_plane_state(state, plane);
>> +             if (IS_ERR(plane_state))
>> +                     return PTR_ERR(plane_state);
>> +     }
>> +
>> +     return 0;
>> +}
>> +
>> +static int
>> +skl_compute_ddb(struct drm_atomic_state *state)
>>  {
>>       struct drm_device *dev = state->dev;
>>       struct drm_i915_private *dev_priv = to_i915(dev);
>> @@ -4923,6 +4854,14 @@ static int skl_update_pipe_wm(struct drm_crtc_state *cstate,
>>               cstate = intel_atomic_get_crtc_state(state, intel_crtc);
>>               if (IS_ERR(cstate))
>>                       return PTR_ERR(cstate);
>> +
>> +             ret = skl_allocate_pipe_ddb(cstate, ddb);
>> +             if (ret)
>> +                     return ret;
>> +
>> +             ret = skl_ddb_add_affected_planes(cstate);
>> +             if (ret)
>> +                     return ret;
>>       }
>>
>>       return 0;
>> @@ -5012,7 +4951,7 @@ static int skl_update_pipe_wm(struct drm_crtc_state *cstate,
>>       /* Clear all dirty flags */
>>       results->dirty_pipes = 0;
>>
>> -     ret = skl_include_affected_crtcs(state);
>> +     ret = skl_compute_ddb(state);
>>       if (ret)
>>               return ret;
>>
>> --
>> 1.9.1
>>
>
> --
> Matt Roper
> Graphics Software Engineer
> IoTG Platform Enabling & Development
> Intel Corporation
> (916) 356-2795
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx



-- 
Rodrigo Vivi
Blog: http://blog.vivi.eng.br


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