[Intel-gfx] [PATCH v4 6/9] drm/i915/tc/tgl: Implement TC cold sequences
Imre Deak
imre.deak at intel.com
Tue Apr 14 17:39:12 UTC 2020
On Mon, Apr 13, 2020 at 09:45:12AM -0700, José Roberto de Souza wrote:
> TC ports can enter in TCCOLD to save power and is required to request
> to PCODE to exit this state before use or read to TC registers.
>
> For TGL there is a new MBOX command to do that with a parameter to ask
> PCODE to exit and block TCCOLD entry or unblock TCCOLD entry.
>
> So adding a new power domain to reuse the refcount and only allow
> TC cold when all TC ports are not in use.
>
> v2:
> - fixed missing case in intel_display_power_domain_str()
> - moved tgl_tc_cold_request to intel_display_power.c
> - renamed TGL_TC_COLD_OFF to TGL_TC_COLD_OFF_POWER_DOMAINS
> - added all TC and TBT aux power domains to
> TGL_TC_COLD_OFF_POWER_DOMAINS
>
> v3:
> - added one msec sleep when PCODE returns -EAGAIN
> - added timeout of 5msec to not loop forever if
> sandybridge_pcode_write_timeout() keeps returning -EAGAIN
>
> v4:
> - Made failure to block or unblock TC cold a error
> - removed 5msec timeout, intead giving PCODE 1msec by up 3 times to
> recover from the internal error
>
> BSpec: 49294
> Cc: Imre Deak <imre.deak at intel.com>
> Cc: Cooper Chiou <cooper.chiou at intel.com>
> Cc: Kai-Heng Feng <kai.heng.feng at canonical.com>
> Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> ---
> .../drm/i915/display/intel_display_power.c | 107 ++++++++++++++++++
> .../drm/i915/display/intel_display_power.h | 1 +
> drivers/gpu/drm/i915/display/intel_tc.c | 17 ++-
> drivers/gpu/drm/i915/i915_reg.h | 4 +
> 4 files changed, 126 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c b/drivers/gpu/drm/i915/display/intel_display_power.c
> index 50bed2d1dd13..00de926aaccf 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_power.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_power.c
> @@ -151,6 +151,8 @@ intel_display_power_domain_str(enum intel_display_power_domain domain)
> return "GT_IRQ";
> case POWER_DOMAIN_DPLL_DC_OFF:
> return "DPLL_DC_OFF";
> + case POWER_DOMAIN_TC_COLD_OFF:
> + return "TC_COLD_OFF";
> default:
> MISSING_CASE(domain);
> return "?";
> @@ -2861,6 +2863,21 @@ void intel_display_power_put(struct drm_i915_private *dev_priv,
> #define TGL_AUX_I_TBT6_IO_POWER_DOMAINS ( \
> BIT_ULL(POWER_DOMAIN_AUX_I_TBT))
>
> +#define TGL_TC_COLD_OFF_POWER_DOMAINS ( \
> + BIT_ULL(POWER_DOMAIN_AUX_D) | \
> + BIT_ULL(POWER_DOMAIN_AUX_E) | \
> + BIT_ULL(POWER_DOMAIN_AUX_F) | \
> + BIT_ULL(POWER_DOMAIN_AUX_G) | \
> + BIT_ULL(POWER_DOMAIN_AUX_H) | \
> + BIT_ULL(POWER_DOMAIN_AUX_I) | \
> + BIT_ULL(POWER_DOMAIN_AUX_D_TBT) | \
> + BIT_ULL(POWER_DOMAIN_AUX_E_TBT) | \
> + BIT_ULL(POWER_DOMAIN_AUX_F_TBT) | \
> + BIT_ULL(POWER_DOMAIN_AUX_G_TBT) | \
> + BIT_ULL(POWER_DOMAIN_AUX_H_TBT) | \
> + BIT_ULL(POWER_DOMAIN_AUX_I_TBT) | \
> + BIT_ULL(POWER_DOMAIN_TC_COLD_OFF))
> +
> static const struct i915_power_well_ops i9xx_always_on_power_well_ops = {
> .sync_hw = i9xx_power_well_sync_hw_noop,
> .enable = i9xx_always_on_power_well_noop,
> @@ -3963,6 +3980,90 @@ static const struct i915_power_well_desc ehl_power_wells[] = {
> },
> };
>
> +static void
> +tgl_tc_cold_request(struct drm_i915_private *i915, bool block)
> +{
> + u8 tries = 0;
> + int ret;
> +
> + while (1) {
> + u32 low_val = 0, high_val;
> +
> + if (block)
> + high_val = TGL_PCODE_EXIT_TCCOLD_DATA_H_BLOCK_REQ;
> + else
> + high_val = TGL_PCODE_EXIT_TCCOLD_DATA_H_UNBLOCK_REQ;
> +
> + /*
> + * Spec states that we should timeout the request after 200us
> + * but the function below will timeout after 500us
> + */
> + ret = sandybridge_pcode_read(i915, TGL_PCODE_TCCOLD, &low_val,
> + &high_val);
> + if (ret == 0) {
> + if (block &&
> + (low_val & TGL_PCODE_EXIT_TCCOLD_DATA_L_EXIT_FAILED))
> + ret = -EIO;
> + else
> + break;
> + }
> +
> + if (++tries == 3)
> + break;
> +
> + msleep(1);
Why did this go back to msleep unconditionally? Doing that only for
ret == -EAGAIN made sense to me, since that is only the case where you'd
want to avoid busy looping.
> + }
> +
> + if (ret)
> + drm_err(&i915->drm, "TC cold %sblock failed\n",
> + block ? "" : "un");
> + else
> + drm_dbg_kms(&i915->drm, "TC cold %sblock succeeded\n",
> + block ? "" : "un");
> +}
> +
> +static void
> +tgl_tc_cold_off_power_well_enable(struct drm_i915_private *i915,
> + struct i915_power_well *power_well)
> +{
> + tgl_tc_cold_request(i915, true);
> +}
> +
> +static void
> +tgl_tc_cold_off_power_well_disable(struct drm_i915_private *i915,
> + struct i915_power_well *power_well)
> +{
> + tgl_tc_cold_request(i915, false);
> +}
> +
> +static void
> +tgl_tc_cold_off_power_well_sync_hw(struct drm_i915_private *i915,
> + struct i915_power_well *power_well)
> +{
> + if (power_well->count > 0)
> + tgl_tc_cold_off_power_well_enable(i915, power_well);
> + else
> + tgl_tc_cold_off_power_well_disable(i915, power_well);
> +}
> +
> +static bool
> +tgl_tc_cold_off_power_well_is_enabled(struct drm_i915_private *dev_priv,
> + struct i915_power_well *power_well)
> +{
> + /*
> + * Not the correctly implementation but there is no way to just read it
> + * from PCODE, so returning count to avoid state mismatch errors
> + */
> + return power_well->count;
> +}
> +
> +static const struct i915_power_well_ops tgl_tc_cold_off_ops = {
> + .sync_hw = tgl_tc_cold_off_power_well_sync_hw,
> + .enable = tgl_tc_cold_off_power_well_enable,
> + .disable = tgl_tc_cold_off_power_well_disable,
> + .is_enabled = tgl_tc_cold_off_power_well_is_enabled,
> +};
> +
> static const struct i915_power_well_desc tgl_power_wells[] = {
> {
> .name = "always-on",
> @@ -4290,6 +4391,12 @@ static const struct i915_power_well_desc tgl_power_wells[] = {
> .hsw.irq_pipe_mask = BIT(PIPE_D),
> },
> },
> + {
> + .name = "TC cold off",
> + .domains = TGL_TC_COLD_OFF_POWER_DOMAINS,
> + .ops = &tgl_tc_cold_off_ops,
> + .id = DISP_PW_ID_NONE,
> + },
> };
>
> static int
> diff --git a/drivers/gpu/drm/i915/display/intel_display_power.h b/drivers/gpu/drm/i915/display/intel_display_power.h
> index da64a5edae7a..070457e7b948 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_power.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_power.h
> @@ -76,6 +76,7 @@ enum intel_display_power_domain {
> POWER_DOMAIN_MODESET,
> POWER_DOMAIN_GT_IRQ,
> POWER_DOMAIN_DPLL_DC_OFF,
> + POWER_DOMAIN_TC_COLD_OFF,
> POWER_DOMAIN_INIT,
>
> POWER_DOMAIN_NUM,
> diff --git a/drivers/gpu/drm/i915/display/intel_tc.c b/drivers/gpu/drm/i915/display/intel_tc.c
> index 0cf33d4d21c3..521a94c63640 100644
> --- a/drivers/gpu/drm/i915/display/intel_tc.c
> +++ b/drivers/gpu/drm/i915/display/intel_tc.c
> @@ -53,16 +53,27 @@ tc_port_load_fia_params(struct drm_i915_private *i915,
> }
> }
>
> +static enum intel_display_power_domain
> +tc_cold_get_power_domain(struct intel_digital_port *dig_port)
> +{
> + struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
> +
> + if (INTEL_GEN(i915) == 11)
> + return intel_legacy_aux_to_power_domain(dig_port->aux_ch);
> + else
> + return POWER_DOMAIN_TC_COLD_OFF;
> +}
> +
> static intel_wakeref_t
> tc_cold_block(struct intel_digital_port *dig_port)
> {
> struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
> enum intel_display_power_domain domain;
>
> - if (INTEL_GEN(i915) != 11 || !dig_port->tc_legacy_port)
> + if (INTEL_GEN(i915) == 11 && !dig_port->tc_legacy_port)
> return 0;
>
> - domain = intel_legacy_aux_to_power_domain(dig_port->aux_ch);
> + domain = tc_cold_get_power_domain(dig_port);
> return intel_display_power_get(i915, domain);
> }
>
> @@ -80,7 +91,7 @@ tc_cold_unblock(struct intel_digital_port *dig_port, intel_wakeref_t wakeref)
> if (wakeref == 0)
> return;
>
> - domain = intel_legacy_aux_to_power_domain(dig_port->aux_ch);
> + domain = tc_cold_get_power_domain(dig_port);
> intel_display_power_put_async(i915, domain, wakeref);
> }
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index e4667add70b0..39f281fe6d6c 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -9111,6 +9111,10 @@ enum {
> #define ICL_PCODE_EXIT_TCCOLD 0x12
> #define HSW_PCODE_DE_WRITE_FREQ_REQ 0x17
> #define DISPLAY_IPS_CONTROL 0x19
> +#define TGL_PCODE_TCCOLD 0x26
> +#define TGL_PCODE_EXIT_TCCOLD_DATA_L_EXIT_FAILED REG_BIT(0)
> +#define TGL_PCODE_EXIT_TCCOLD_DATA_H_BLOCK_REQ 0
> +#define TGL_PCODE_EXIT_TCCOLD_DATA_H_UNBLOCK_REQ REG_BIT(0)
> /* See also IPS_CTL */
> #define IPS_PCODE_CONTROL (1 << 30)
> #define HSW_PCODE_DYNAMIC_DUTY_CYCLE_CONTROL 0x1A
> --
> 2.26.0
>
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