[Intel-gfx] [PATCH v5] drm/i915/vlv: WA to fix Voltage not getting dropped to Vmin when Gfx is power gated.
Ville Syrjälä
ville.syrjala at linux.intel.com
Thu Jan 30 18:02:11 CET 2014
On Thu, Jan 30, 2014 at 09:54:41PM +0530, deepak.s at intel.com wrote:
> From: Deepak S <deepak.s at intel.com>
>
> When we enter RC6 and GFX Clocks are off, the voltage remains higher
> than Vmin. When we try to set the freq to RPn, it might fail since the
> Gfx clocks are down. So to fix this in Gfx idle, Bring the GFX clock up
> and set the freq to RPn then move GFx down.
>
> v2: remove vlv_update_rps_cur_delay function. Update commit message (Daniel)
>
> v3: Fix the timeout during wait for gfx clock (Jesse)
>
> v4: addressed comments on set freq and punit wait (Ville)
>
> v5: use wait_for while waiting for GFX clk to be up. (Daniel)
> update cur_delay before requesting min_delay. (Ville)
>
> Signed-off-by: Deepak S <deepak.s at intel.com>
> ---
> drivers/gpu/drm/i915/i915_drv.h | 2 ++
> drivers/gpu/drm/i915/i915_irq.c | 2 +-
> drivers/gpu/drm/i915/i915_reg.h | 4 +++
> drivers/gpu/drm/i915/intel_pm.c | 57 ++++++++++++++++++++++++++++++++++++++++-
> 4 files changed, 63 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index ac5cd7e..6f9108d 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1961,6 +1961,8 @@ extern void intel_console_resume(struct work_struct *work);
> void i915_queue_hangcheck(struct drm_device *dev);
> void i915_handle_error(struct drm_device *dev, bool wedged);
>
> +void gen6_set_pm_mask(struct drm_i915_private *dev_priv, u32 pm_iir,
> + int new_delay);
> extern void intel_irq_init(struct drm_device *dev);
> extern void intel_hpd_init(struct drm_device *dev);
>
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index b226ae6..acbee73 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -986,7 +986,7 @@ static void notify_ring(struct drm_device *dev,
> i915_queue_hangcheck(dev);
> }
>
> -static void gen6_set_pm_mask(struct drm_i915_private *dev_priv,
> +void gen6_set_pm_mask(struct drm_i915_private *dev_priv,
> u32 pm_iir, int new_delay)
> {
> if (pm_iir & GEN6_PM_RP_UP_THRESHOLD) {
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index cbbaf26..00d2f2d 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -4949,6 +4949,10 @@
> GEN6_PM_RP_DOWN_THRESHOLD | \
> GEN6_PM_RP_DOWN_TIMEOUT)
>
> +#define VLV_GTLC_SURVIVABILITY_REG 0x130098
> +#define VLV_GFX_CLK_STATUS_BIT (1<<3)
> +#define VLV_GFX_CLK_FORCE_ON_BIT (1<<2)
> +
> #define GEN6_GT_GFX_RC6_LOCKED 0x138104
> #define VLV_COUNTER_CONTROL 0x138104
> #define VLV_COUNT_RANGE_HIGH (1<<15)
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index 4876ba5..36795ee 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -3038,6 +3038,60 @@ void gen6_set_rps(struct drm_device *dev, u8 val)
> trace_intel_gpu_freq_change(val * 50);
> }
>
> +/* vlv_set_rps_idle: Set the frequency to Rpn if Gfx clocks are down
> + *
> + * * If Gfx is Idle, then
> + * 1. Mask Turbo interrupts
> + * 2. Bring up Gfx clock
> + * 3. Change the freq to Rpn and wait till P-Unit updates freq
> + * 4. Clear the Force GFX CLK ON bit so that Gfx can down
> + * 5. Unmask Turbo interrupts
> +*/
> +static void vlv_set_rps_idle(struct drm_i915_private *dev_priv)
> +{
> + /*
> + * When we are idle. Drop to min voltage state.
> + */
> +
> + if (dev_priv->rps.cur_delay <= dev_priv->rps.min_delay)
> + return;
> +
> + /* Mask turbo interrupt so that they will not come in between */
> + I915_WRITE(GEN6_PMINTRMSK, 0xffffffff);
> +
> + /* Bring up the Gfx clock */
> + I915_WRITE(VLV_GTLC_SURVIVABILITY_REG,
> + I915_READ(VLV_GTLC_SURVIVABILITY_REG) |
> + VLV_GFX_CLK_FORCE_ON_BIT);
> +
> + if (wait_for(((VLV_GFX_CLK_STATUS_BIT &
> + I915_READ(VLV_GTLC_SURVIVABILITY_REG)) != 0), 5)) {
> + DRM_ERROR("GFX_CLK_ON request timed out\n");
> + return;
> + }
> +
> + dev_priv->rps.cur_delay = dev_priv->rps.min_delay;
> +
> + vlv_punit_write(dev_priv, PUNIT_REG_GPU_FREQ_REQ,
> + dev_priv->rps.min_delay);
> +
> + if (wait_for_atomic(((vlv_punit_read(dev_priv, PUNIT_REG_GPU_FREQ_STS))
^^^^^^
Still atomic here.
> + & GENFREQSTATUS) == 0, 5))
> + DRM_DEBUG_DRIVER("timed out waiting for Punit\n");
Maybe this should now be an error as well?
> +
> + /* Release the Gfx clock */
> + I915_WRITE(VLV_GTLC_SURVIVABILITY_REG,
> + I915_READ(VLV_GTLC_SURVIVABILITY_REG) &
> + ~VLV_GFX_CLK_FORCE_ON_BIT);
> +
> + /* Unmask Up interrupts */
> + dev_priv->rps.rp_up_masked = true;
Good catch setting this here. I would have forgotton it :)
OK. Fix the atomic (and maybe change to DRM_ERROR for the punit wait,
if you want) and you can add:
Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> + gen6_set_pm_mask(dev_priv, GEN6_PM_RP_DOWN_THRESHOLD,
> + dev_priv->rps.min_delay);
> +}
> +
> +
> +
> void gen6_rps_idle(struct drm_i915_private *dev_priv)
> {
> struct drm_device *dev = dev_priv->dev;
> @@ -3045,7 +3099,7 @@ void gen6_rps_idle(struct drm_i915_private *dev_priv)
> mutex_lock(&dev_priv->rps.hw_lock);
> if (dev_priv->rps.enabled) {
> if (IS_VALLEYVIEW(dev))
> - valleyview_set_rps(dev_priv->dev, dev_priv->rps.min_delay);
> + vlv_set_rps_idle(dev_priv);
> else
> gen6_set_rps(dev_priv->dev, dev_priv->rps.min_delay);
> dev_priv->rps.last_adj = 0;
> @@ -4276,6 +4330,7 @@ void intel_gpu_ips_teardown(void)
> i915_mch_dev = NULL;
> spin_unlock_irq(&mchdev_lock);
> }
> +
> static void intel_init_emon(struct drm_device *dev)
> {
> struct drm_i915_private *dev_priv = dev->dev_private;
> --
> 1.8.5.2
>
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--
Ville Syrjälä
Intel OTC
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