[Intel-gfx] [PATCH v2 13/13] drm/i915: Acquire P-Unit access when modifying P-Unit settings

Hans de Goede hdegoede at redhat.com
Sat Jan 28 17:18:45 UTC 2017


Hi,

On 01/28/2017 05:25 PM, Hans de Goede wrote:
> Hi,
>
> On 01/27/2017 02:51 PM, Ville Syrjälä wrote:
>> On Mon, Jan 23, 2017 at 10:09:58PM +0100, Hans de Goede wrote:
>>> Make sure the P-Unit or the PMIC i2c bus is not in use when we send a
>>> request to the P-Unit by calling iosf_mbi_punit_acquire() / _release()
>>> around P-Unit write accesses.
>>
>> Can't we just stuff the calls into the actual punit write function
>> rather than sprinkling them all over the place?
>
> punit access is acquired across sections like this:
>
>         iosf_mbi_punit_acquire();
>
>         val = vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ);
>         val &= ~DSPFREQGUAR_MASK;
>         val |= (cmd << DSPFREQGUAR_SHIFT);
>         vlv_punit_write(dev_priv, PUNIT_REG_DSPFREQ, val);
>         if (wait_for((vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ) &
>                       DSPFREQSTAT_MASK) == (cmd << DSPFREQSTAT_SHIFT),
>                      50)) {
>                 DRM_ERROR("timed out waiting for CDclk change\n");
>         }
>         iosf_mbi_punit_release();
>
> Where we want to wait for the requested change to have taken
> effect before releasing the punit.
>
>>
>> + a comment would be nice why it's there.
>
> I will add comments to the acquire calls.
>
>> Do we need a kconfig select/depends on the iosf_mbi thing? Or some
>> ifdefs?
>
> No, the iosf_mbi header defines empty inline versions of
> iosf_mbi_punit_acquire / _release if IOSF_MBI is disabled,
> this does mean that iosf_mbi must be builtin if the i915
> driver is. I'll add:
>
>     depends on DRM_I915=IOSF_MBI || IOSF_MBI=y
>
> To the i915 Kconfig to enforce this.

Hmm, ok so that does not work (long cyclic dependency through the
selection of ACPI_VIDEO).

So I've now added this instead:

	# iosf_mbi needs to be builtin if we are builtin
	select IOSF_MBI if DRM_I915=y

Regards,

Hans


>>> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=155241
>>> Signed-off-by: Hans de Goede <hdegoede at redhat.com>
>>> Tested-by: tagorereddy <tagore.chandan at gmail.com>
>>> ---
>>> Changes in v2:
>>> -Spelling: P-Unit, PMIC
>>> -Adjust for iosf_mbi_punit_lock/_unlock to _acquire/_release rename
>>> ---
>>>  drivers/gpu/drm/i915/intel_display.c    | 6 ++++++
>>>  drivers/gpu/drm/i915/intel_pm.c         | 9 +++++++++
>>>  drivers/gpu/drm/i915/intel_runtime_pm.c | 9 +++++++++
>>>  3 files changed, 24 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
>>> index 5604701..13e5152 100644
>>> --- a/drivers/gpu/drm/i915/intel_display.c
>>> +++ b/drivers/gpu/drm/i915/intel_display.c
>>> @@ -47,6 +47,7 @@
>>>  #include <drm/drm_rect.h>
>>>  #include <linux/dma_remapping.h>
>>>  #include <linux/reservation.h>
>>> +#include <asm/iosf_mbi.h>
>>>
>>>  static bool is_mmio_work(struct intel_flip_work *work)
>>>  {
>>> @@ -6421,6 +6422,8 @@ static void valleyview_set_cdclk(struct drm_device *dev, int cdclk)
>>>          cmd = 0;
>>>
>>>      mutex_lock(&dev_priv->rps.hw_lock);
>>> +    iosf_mbi_punit_acquire();
>>> +
>>>      val = vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ);
>>>      val &= ~DSPFREQGUAR_MASK;
>>>      val |= (cmd << DSPFREQGUAR_SHIFT);
>>> @@ -6430,6 +6433,7 @@ static void valleyview_set_cdclk(struct drm_device *dev, int cdclk)
>>>               50)) {
>>>          DRM_ERROR("timed out waiting for CDclk change\n");
>>>      }
>>> +    iosf_mbi_punit_release();
>>>      mutex_unlock(&dev_priv->rps.hw_lock);
>>>
>>>      mutex_lock(&dev_priv->sb_lock);
>>> @@ -6497,6 +6501,7 @@ static void cherryview_set_cdclk(struct drm_device *dev, int cdclk)
>>>      cmd = DIV_ROUND_CLOSEST(dev_priv->hpll_freq << 1, cdclk) - 1;
>>>
>>>      mutex_lock(&dev_priv->rps.hw_lock);
>>> +    iosf_mbi_punit_acquire();
>>>      val = vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ);
>>>      val &= ~DSPFREQGUAR_MASK_CHV;
>>>      val |= (cmd << DSPFREQGUAR_SHIFT_CHV);
>>> @@ -6506,6 +6511,7 @@ static void cherryview_set_cdclk(struct drm_device *dev, int cdclk)
>>>               50)) {
>>>          DRM_ERROR("timed out waiting for CDclk change\n");
>>>      }
>>> +    iosf_mbi_punit_release();
>>>      mutex_unlock(&dev_priv->rps.hw_lock);
>>>
>>>      intel_update_cdclk(dev_priv);
>>> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
>>> index 249623d..adff84a 100644
>>> --- a/drivers/gpu/drm/i915/intel_pm.c
>>> +++ b/drivers/gpu/drm/i915/intel_pm.c
>>> @@ -32,6 +32,7 @@
>>>  #include "../../../platform/x86/intel_ips.h"
>>>  #include <linux/module.h>
>>>  #include <drm/drm_atomic_helper.h>
>>> +#include <asm/iosf_mbi.h>
>>>
>>>  /**
>>>   * DOC: RC6
>>> @@ -276,6 +277,7 @@ static void chv_set_memory_dvfs(struct drm_i915_private *dev_priv, bool enable)
>>>      u32 val;
>>>
>>>      mutex_lock(&dev_priv->rps.hw_lock);
>>> +    iosf_mbi_punit_acquire();
>>>
>>>      val = vlv_punit_read(dev_priv, PUNIT_REG_DDR_SETUP2);
>>>      if (enable)
>>> @@ -290,6 +292,7 @@ static void chv_set_memory_dvfs(struct drm_i915_private *dev_priv, bool enable)
>>>                FORCE_DDR_FREQ_REQ_ACK) == 0, 3))
>>>          DRM_ERROR("timed out waiting for Punit DDR DVFS request\n");
>>>
>>> +    iosf_mbi_punit_release();
>>>      mutex_unlock(&dev_priv->rps.hw_lock);
>>>  }
>>>
>>> @@ -298,6 +301,7 @@ static void chv_set_memory_pm5(struct drm_i915_private *dev_priv, bool enable)
>>>      u32 val;
>>>
>>>      mutex_lock(&dev_priv->rps.hw_lock);
>>> +    iosf_mbi_punit_acquire();
>>>
>>>      val = vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ);
>>>      if (enable)
>>> @@ -306,6 +310,7 @@ static void chv_set_memory_pm5(struct drm_i915_private *dev_priv, bool enable)
>>>          val &= ~DSP_MAXFIFO_PM5_ENABLE;
>>>      vlv_punit_write(dev_priv, PUNIT_REG_DSPFREQ, val);
>>>
>>> +    iosf_mbi_punit_release();
>>>      mutex_unlock(&dev_priv->rps.hw_lock);
>>>  }
>>>
>>> @@ -4553,6 +4558,7 @@ void vlv_wm_get_hw_state(struct drm_device *dev)
>>>
>>>      if (IS_CHERRYVIEW(dev_priv)) {
>>>          mutex_lock(&dev_priv->rps.hw_lock);
>>> +        iosf_mbi_punit_acquire();
>>>
>>>          val = vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ);
>>>          if (val & DSP_MAXFIFO_PM5_ENABLE)
>>> @@ -4582,6 +4588,7 @@ void vlv_wm_get_hw_state(struct drm_device *dev)
>>>                  wm->level = VLV_WM_LEVEL_DDR_DVFS;
>>>          }
>>>
>>> +        iosf_mbi_punit_release();
>>>          mutex_unlock(&dev_priv->rps.hw_lock);
>>>      }
>>>
>>> @@ -4988,7 +4995,9 @@ static void valleyview_set_rps(struct drm_i915_private *dev_priv, u8 val)
>>>      I915_WRITE(GEN6_PMINTRMSK, gen6_rps_pm_mask(dev_priv, val));
>>>
>>>      if (val != dev_priv->rps.cur_freq) {
>>> +        iosf_mbi_punit_acquire();
>>>          vlv_punit_write(dev_priv, PUNIT_REG_GPU_FREQ_REQ, val);
>>> +        iosf_mbi_punit_release();
>>>          if (!IS_CHERRYVIEW(dev_priv))
>>>              gen6_set_rps_thresholds(dev_priv, val);
>>>      }
>>> diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
>>> index c0b7e95..e66bcc8 100644
>>> --- a/drivers/gpu/drm/i915/intel_runtime_pm.c
>>> +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
>>> @@ -28,6 +28,7 @@
>>>
>>>  #include <linux/pm_runtime.h>
>>>  #include <linux/vgaarb.h>
>>> +#include <asm/iosf_mbi.h>
>>>
>>>  #include "i915_drv.h"
>>>  #include "intel_drv.h"
>>> @@ -1027,6 +1028,8 @@ static void vlv_set_power_well(struct drm_i915_private *dev_priv,
>>>      if (COND)
>>>          goto out;
>>>
>>> +    iosf_mbi_punit_acquire();
>>> +
>>>      ctrl = vlv_punit_read(dev_priv, PUNIT_REG_PWRGT_CTRL);
>>>      ctrl &= ~mask;
>>>      ctrl |= state;
>>> @@ -1037,6 +1040,8 @@ static void vlv_set_power_well(struct drm_i915_private *dev_priv,
>>>                state,
>>>                vlv_punit_read(dev_priv, PUNIT_REG_PWRGT_CTRL));
>>>
>>> +    iosf_mbi_punit_release();
>>> +
>>>  #undef COND
>>>
>>>  out:
>>> @@ -1643,6 +1648,8 @@ static void chv_set_pipe_power_well(struct drm_i915_private *dev_priv,
>>>      if (COND)
>>>          goto out;
>>>
>>> +    iosf_mbi_punit_acquire();
>>> +
>>>      ctrl = vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ);
>>>      ctrl &= ~DP_SSC_MASK(pipe);
>>>      ctrl |= enable ? DP_SSC_PWR_ON(pipe) : DP_SSC_PWR_GATE(pipe);
>>> @@ -1653,6 +1660,8 @@ static void chv_set_pipe_power_well(struct drm_i915_private *dev_priv,
>>>                state,
>>>                vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ));
>>>
>>> +    iosf_mbi_punit_release();
>>> +
>>>  #undef COND
>>>
>>>  out:
>>> --
>>> 2.9.3
>>


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