On DG2 we're supposed to just wait 600us after programming the well before moving on; there won't be an ack from the hardware.
Bspec: 49296 Signed-off-by: Matt Roper matthew.d.roper@intel.com --- .../gpu/drm/i915/display/intel_display_power.c | 16 ++++++++++++++++ .../gpu/drm/i915/display/intel_display_power.h | 6 ++++++ 2 files changed, 22 insertions(+)
diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c b/drivers/gpu/drm/i915/display/intel_display_power.c index 285380079aab..c34ff0947b85 100644 --- a/drivers/gpu/drm/i915/display/intel_display_power.c +++ b/drivers/gpu/drm/i915/display/intel_display_power.c @@ -341,6 +341,17 @@ static void hsw_wait_for_power_well_enable(struct drm_i915_private *dev_priv, { const struct i915_power_well_regs *regs = power_well->desc->hsw.regs; int pw_idx = power_well->desc->hsw.idx; + int enable_delay = power_well->desc->hsw.fixed_enable_delay; + + /* + * For some power wells we're not supposed to watch the status bit for + * an ack, but rather just wait a fixed amount of time and then + * proceed. This is only used on DG2. + */ + if (IS_DG2(dev_priv) && enable_delay) { + usleep_range(enable_delay, 2 * enable_delay); + return; + }
/* Timeout for PW1:10 us, AUX:not specified, other PWs:20 us. */ if (intel_de_wait_for_set(dev_priv, regs->driver, @@ -4828,6 +4839,7 @@ static const struct i915_power_well_desc xelpd_power_wells[] = { { .hsw.regs = &icl_aux_power_well_regs, .hsw.idx = ICL_PW_CTL_IDX_AUX_A, + .hsw.fixed_enable_delay = 600, }, }, { @@ -4838,6 +4850,7 @@ static const struct i915_power_well_desc xelpd_power_wells[] = { { .hsw.regs = &icl_aux_power_well_regs, .hsw.idx = ICL_PW_CTL_IDX_AUX_B, + .hsw.fixed_enable_delay = 600, }, }, { @@ -4848,6 +4861,7 @@ static const struct i915_power_well_desc xelpd_power_wells[] = { { .hsw.regs = &icl_aux_power_well_regs, .hsw.idx = ICL_PW_CTL_IDX_AUX_C, + .hsw.fixed_enable_delay = 600, }, }, { @@ -4858,6 +4872,7 @@ static const struct i915_power_well_desc xelpd_power_wells[] = { { .hsw.regs = &icl_aux_power_well_regs, .hsw.idx = XELPD_PW_CTL_IDX_AUX_D, + .hsw.fixed_enable_delay = 600, }, }, { @@ -4878,6 +4893,7 @@ static const struct i915_power_well_desc xelpd_power_wells[] = { { .hsw.regs = &icl_aux_power_well_regs, .hsw.idx = TGL_PW_CTL_IDX_AUX_TC1, + .hsw.fixed_enable_delay = 600, }, }, { diff --git a/drivers/gpu/drm/i915/display/intel_display_power.h b/drivers/gpu/drm/i915/display/intel_display_power.h index 4f0917df4375..22367b5cba96 100644 --- a/drivers/gpu/drm/i915/display/intel_display_power.h +++ b/drivers/gpu/drm/i915/display/intel_display_power.h @@ -223,6 +223,12 @@ struct i915_power_well_desc { u8 idx; /* Mask of pipes whose IRQ logic is backed by the pw */ u8 irq_pipe_mask; + /* + * Instead of waiting for the status bit to ack enables, + * just wait a specific amount of time and then consider + * the well enabled. + */ + u16 fixed_enable_delay; /* The pw is backing the VGA functionality */ bool has_vga:1; bool has_fuses:1;