[PATCH 04/10] drm/i915/xe3lpd: Update pmdemand programming
Gustavo Sousa
gustavo.sousa at intel.com
Wed Oct 9 13:53:08 UTC 2024
Quoting Govindapillai, Vinod (2024-10-09 10:09:45-03:00)
>Hi Matt,
>
>Probably you missed one change...
>
>On Tue, 2024-10-08 at 15:37 -0700, Matt Atwood wrote:
>> From: Matt Roper <matthew.d.roper at intel.com>
>>
>> There are some minor changes to pmdemand handling on Xe3:
>> - Active scalers are no longer tracked. We can simply skip the readout
>> and programming of this field.
>> - Active dbuf slices are no longer tracked. We should skip the readout
>> and programming of this field and also make sure that it stays 0 in
>> our software bookkeeping so that we won't erroneously return true
>> from intel_pmdemand_needs_update() due to mismatches.
>> - Even though there aren't enough pipes to utilize them, the size of
>> the 'active pipes' field has expanded to four bits, taking over the
>> register bits previously used for dbuf slices. Since the lower bits
>> of the mask have moved, we need to update our reads/writes to handle
>> this properly.
>>
>> Bspec: 68883, 69125
>> Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
>> Signed-off-by: Matt Atwood <matthew.s.atwood at intel.com>
>> ---
>> drivers/gpu/drm/i915/display/intel_pmdemand.c | 61 +++++++++++++------
>> drivers/gpu/drm/i915/display/intel_pmdemand.h | 4 +-
>> drivers/gpu/drm/i915/i915_reg.h | 1 +
>> 3 files changed, 45 insertions(+), 21 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_pmdemand.c
>> b/drivers/gpu/drm/i915/display/intel_pmdemand.c
>> index ceaf9e3147da..9af2f83d3a75 100644
>> --- a/drivers/gpu/drm/i915/display/intel_pmdemand.c
>> +++ b/drivers/gpu/drm/i915/display/intel_pmdemand.c
>> @@ -258,6 +258,7 @@ intel_pmdemand_connector_needs_update(struct intel_atomic_state *state)
>>
>> static bool intel_pmdemand_needs_update(struct intel_atomic_state *state)
>> {
>> + struct drm_i915_private *i915 = to_i915(state->base.dev);
>> const struct intel_bw_state *new_bw_state, *old_bw_state;
>> const struct intel_cdclk_state *new_cdclk_state, *old_cdclk_state;
>> const struct intel_crtc_state *new_crtc_state, *old_crtc_state;
>> @@ -274,12 +275,16 @@ static bool intel_pmdemand_needs_update(struct intel_atomic_state *state)
>> new_dbuf_state = intel_atomic_get_new_dbuf_state(state);
>> old_dbuf_state = intel_atomic_get_old_dbuf_state(state);
>> if (new_dbuf_state &&
>> - (new_dbuf_state->active_pipes !=
>> - old_dbuf_state->active_pipes ||
>> - new_dbuf_state->enabled_slices !=
>> - old_dbuf_state->enabled_slices))
>> + new_dbuf_state->active_pipes != old_dbuf_state->active_pipes)
>> return true;
>>
>> + if (DISPLAY_VER(i915) < 30) {
>> + if (new_dbuf_state &&
>> + new_dbuf_state->enabled_slices !=
>> + old_dbuf_state->enabled_slices)
>> + return true;
>> + }
>> +
>> new_cdclk_state = intel_atomic_get_new_cdclk_state(state);
>> old_cdclk_state = intel_atomic_get_old_cdclk_state(state);
>> if (new_cdclk_state &&
>> @@ -329,8 +334,10 @@ int intel_pmdemand_atomic_check(struct intel_atomic_state *state)
>>
>> new_pmdemand_state->params.active_pipes =
>> min_t(u8, hweight8(new_dbuf_state->active_pipes), 3);
>In xe3, min could be 4 (11b for 3 pipes and 100b for 4 pipes.)
Good catch!
In this case, we could either:
- Apply min_t() only for pre-xe3 and just use the value directly for
xe3. Bspec mentions that Pcode should clamp to the maximum defined
number of pipes.
- Define a local max_active_pipes variable, using 3 for pre-xe3 and the
number of possible pipes for xe3. Then use that variable in min_t().
I would prefer the latter, which does what Pcode is also supposed to do.
This little redundancy doesn't hurt and make things safer.
--
Gustavo Sousa
>
>BR
>vinod
>
>> - new_pmdemand_state->params.active_dbufs =
>> - min_t(u8, hweight8(new_dbuf_state->enabled_slices), 3);
>> +
>> + if (DISPLAY_VER(i915) < 30)
>> + new_pmdemand_state->params.active_dbufs =
>> + min_t(u8, hweight8(new_dbuf_state->enabled_slices), 3);
>>
>> new_cdclk_state = intel_atomic_get_cdclk_state(state);
>> if (IS_ERR(new_cdclk_state))
>> @@ -395,27 +402,32 @@ intel_pmdemand_init_pmdemand_params(struct drm_i915_private *i915,
>>
>> reg2 = intel_de_read(i915, XELPDP_INITIATE_PMDEMAND_REQUEST(1));
>>
>> - /* Set 1*/
>> pmdemand_state->params.qclk_gv_bw =
>> REG_FIELD_GET(XELPDP_PMDEMAND_QCLK_GV_BW_MASK, reg1);
>> pmdemand_state->params.voltage_index =
>> REG_FIELD_GET(XELPDP_PMDEMAND_VOLTAGE_INDEX_MASK, reg1);
>> pmdemand_state->params.qclk_gv_index =
>> REG_FIELD_GET(XELPDP_PMDEMAND_QCLK_GV_INDEX_MASK, reg1);
>> - pmdemand_state->params.active_pipes =
>> - REG_FIELD_GET(XELPDP_PMDEMAND_PIPES_MASK, reg1);
>> - pmdemand_state->params.active_dbufs =
>> - REG_FIELD_GET(XELPDP_PMDEMAND_DBUFS_MASK, reg1);
>> pmdemand_state->params.active_phys =
>> REG_FIELD_GET(XELPDP_PMDEMAND_PHYS_MASK, reg1);
>>
>> - /* Set 2*/
>> pmdemand_state->params.cdclk_freq_mhz =
>> REG_FIELD_GET(XELPDP_PMDEMAND_CDCLK_FREQ_MASK, reg2);
>> pmdemand_state->params.ddiclk_max =
>> REG_FIELD_GET(XELPDP_PMDEMAND_DDICLK_FREQ_MASK, reg2);
>> - pmdemand_state->params.scalers =
>> - REG_FIELD_GET(XELPDP_PMDEMAND_SCALERS_MASK, reg2);
>> +
>> + if (DISPLAY_VER(i915) >= 30) {
>> + pmdemand_state->params.active_pipes =
>> + REG_FIELD_GET(XE3_PMDEMAND_PIPES_MASK, reg1);
>> + } else {
>> + pmdemand_state->params.active_pipes =
>> + REG_FIELD_GET(XELPDP_PMDEMAND_PIPES_MASK, reg1);
>> + pmdemand_state->params.active_dbufs =
>> + REG_FIELD_GET(XELPDP_PMDEMAND_DBUFS_MASK, reg1);
>> +
>> + pmdemand_state->params.scalers =
>> + REG_FIELD_GET(XELPDP_PMDEMAND_SCALERS_MASK, reg2);
>> + }
>>
>> unlock:
>> mutex_unlock(&i915->display.pmdemand.lock);
>> @@ -442,6 +454,10 @@ void intel_pmdemand_program_dbuf(struct drm_i915_private *i915,
>> {
>> u32 dbufs = min_t(u32, hweight8(dbuf_slices), 3);
>>
>> + /* PM Demand only tracks active dbufs on pre-Xe3 platforms */
>> + if (DISPLAY_VER(i915) >= 30)
>> + return;
>> +
>> mutex_lock(&i915->display.pmdemand.lock);
>> if (drm_WARN_ON(&i915->drm,
>> !intel_pmdemand_check_prev_transaction(i915)))
>> @@ -460,7 +476,8 @@ void intel_pmdemand_program_dbuf(struct drm_i915_private *i915,
>> }
>>
>> static void
>> -intel_pmdemand_update_params(const struct intel_pmdemand_state *new,
>> +intel_pmdemand_update_params(struct drm_i915_private *i915,
>> + const struct intel_pmdemand_state *new,
>> const struct intel_pmdemand_state *old,
>> u32 *reg1, u32 *reg2, bool serialized)
>> {
>> @@ -495,16 +512,22 @@ intel_pmdemand_update_params(const struct intel_pmdemand_state *new,
>> update_reg(reg1, qclk_gv_bw, XELPDP_PMDEMAND_QCLK_GV_BW_MASK);
>> update_reg(reg1, voltage_index, XELPDP_PMDEMAND_VOLTAGE_INDEX_MASK);
>> update_reg(reg1, qclk_gv_index, XELPDP_PMDEMAND_QCLK_GV_INDEX_MASK);
>> - update_reg(reg1, active_pipes, XELPDP_PMDEMAND_PIPES_MASK);
>> - update_reg(reg1, active_dbufs, XELPDP_PMDEMAND_DBUFS_MASK);
>> update_reg(reg1, active_phys, XELPDP_PMDEMAND_PHYS_MASK);
>>
>> /* Set 2*/
>> update_reg(reg2, cdclk_freq_mhz, XELPDP_PMDEMAND_CDCLK_FREQ_MASK);
>> update_reg(reg2, ddiclk_max, XELPDP_PMDEMAND_DDICLK_FREQ_MASK);
>> - update_reg(reg2, scalers, XELPDP_PMDEMAND_SCALERS_MASK);
>> update_reg(reg2, plls, XELPDP_PMDEMAND_PLLS_MASK);
>>
>> + if (DISPLAY_VER(i915) >= 30) {
>> + update_reg(reg1, active_pipes, XE3_PMDEMAND_PIPES_MASK);
>> + } else {
>> + update_reg(reg1, active_pipes, XELPDP_PMDEMAND_PIPES_MASK);
>> + update_reg(reg1, active_dbufs, XELPDP_PMDEMAND_DBUFS_MASK);
>> +
>> + update_reg(reg2, scalers, XELPDP_PMDEMAND_SCALERS_MASK);
>> + }
>> +
>> #undef update_reg
>> }
>>
>> @@ -529,7 +552,7 @@ intel_pmdemand_program_params(struct drm_i915_private *i915,
>> reg2 = intel_de_read(i915, XELPDP_INITIATE_PMDEMAND_REQUEST(1));
>> mod_reg2 = reg2;
>>
>> - intel_pmdemand_update_params(new, old, &mod_reg1, &mod_reg2,
>> + intel_pmdemand_update_params(i915, new, old, &mod_reg1, &mod_reg2,
>> serialized);
>>
>> if (reg1 != mod_reg1) {
>> diff --git a/drivers/gpu/drm/i915/display/intel_pmdemand.h
>> b/drivers/gpu/drm/i915/display/intel_pmdemand.h
>> index 128fd61f8f14..a1c49efdc493 100644
>> --- a/drivers/gpu/drm/i915/display/intel_pmdemand.h
>> +++ b/drivers/gpu/drm/i915/display/intel_pmdemand.h
>> @@ -20,14 +20,14 @@ struct pmdemand_params {
>> u8 voltage_index;
>> u8 qclk_gv_index;
>> u8 active_pipes;
>> - u8 active_dbufs;
>> + u8 active_dbufs; /* pre-Xe3 only */
>> /* Total number of non type C active phys from active_phys_mask */
>> u8 active_phys;
>> u8 plls;
>> u16 cdclk_freq_mhz;
>> /* max from ddi_clocks[] */
>> u16 ddiclk_max;
>> - u8 scalers;
>> + u8 scalers; /* pre-Xe3 only */
>> };
>>
>> struct intel_pmdemand_state {
>> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
>> index 818142f5a10c..d30459f8d1cb 100644
>> --- a/drivers/gpu/drm/i915/i915_reg.h
>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>> @@ -2705,6 +2705,7 @@
>> #define XELPDP_PMDEMAND_QCLK_GV_BW_MASK REG_GENMASK(31, 16)
>> #define XELPDP_PMDEMAND_VOLTAGE_INDEX_MASK REG_GENMASK(14, 12)
>> #define XELPDP_PMDEMAND_QCLK_GV_INDEX_MASK REG_GENMASK(11, 8)
>> +#define XE3_PMDEMAND_PIPES_MASK REG_GENMASK(7, 4)
>> #define XELPDP_PMDEMAND_PIPES_MASK REG_GENMASK(7, 6)
>> #define XELPDP_PMDEMAND_DBUFS_MASK REG_GENMASK(5, 4)
>> #define XELPDP_PMDEMAND_PHYS_MASK REG_GENMASK(2, 0)
>
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