Re: [PATCH 1/1] drm/i915: Tracepoints for profiling DC9 entry and exit programming

From: Daniel Vetter <daniel@ffwll.ch>
To: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Cc: intel-gfx@lists.freedesktop.org
Subject: Re: [PATCH 1/1] drm/i915: Tracepoints for profiling DC9 entry and exit programming
Date: Wed, 17 Jun 2015 13:30:09 +0200	[thread overview]
Message-ID: <20150617113009.GG23637@phenom.ffwll.local> (raw)
In-Reply-To: <1434538270-22258-1-git-send-email-sagar.a.kamble@intel.com>

On Wed, Jun 17, 2015 at 04:21:10PM +0530, Sagar Arun Kamble wrote:
> DC9 entry and exit programming is critical part of suspend/resume
> sequences. This patch adds tracepoints that can help analyze time
> taken using analyze_suspend.py/FTrace.
> 
> Change-Id: I22fca5313c4349f8937eeb5a1c441c8ef76e5f4e
> Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>

Tracepoints are for system profiling when benchmarking and all that. What
exactly is this here for?

Also note that tracepoints are pretty much ABI, so high standards apply
here.
-Daniel

> ---
>  drivers/gpu/drm/i915/i915_drv.c | 9 +++++++++
>  drivers/gpu/drm/i915/i915_reg.h | 1 +
>  2 files changed, 10 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index 78ef0bb..6797650 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -39,6 +39,7 @@
>  #include <linux/module.h>
>  #include <linux/pm_runtime.h>
>  #include <drm/drm_crtc_helper.h>
> +#include <trace/events/power.h>
>  
>  static struct drm_driver driver;
>  
> @@ -1061,12 +1062,16 @@ static int bxt_suspend_complete(struct drm_i915_private *dev_priv)
>  {
>  	struct drm_device *dev = dev_priv->dev;
>  
> +	trace_suspend_resume(TPS("dc_state_entry"), DC9_STATE, true);
> +
>  	/* TODO: when DC5 support is added disable DC5 here. */
>  
>  	broxton_ddi_phy_uninit(dev);
>  	broxton_uninit_cdclk(dev);
>  	bxt_enable_dc9(dev_priv);
>  
> +	trace_suspend_resume(TPS("dc_state_entry"), DC9_STATE, false);
> +
>  	return 0;
>  }
>  
> @@ -1076,6 +1081,8 @@ static int bxt_resume_prepare(struct drm_i915_private *dev_priv)
>  
>  	/* TODO: when CSR FW support is added make sure the FW is loaded */
>  
> +	trace_suspend_resume(TPS("dc_state_exit"), DC9_STATE, true);
> +
>  	bxt_disable_dc9(dev_priv);
>  
>  	/*
> @@ -1086,6 +1093,8 @@ static int bxt_resume_prepare(struct drm_i915_private *dev_priv)
>  	broxton_ddi_phy_init(dev);
>  	intel_prepare_ddi(dev);
>  
> +	trace_suspend_resume(TPS("dc_state_exit"), DC9_STATE, false);
> +
>  	return 0;
>  }
>  
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 0b979ad..cf83ec8 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -7290,6 +7290,7 @@ enum skl_disp_power_wells {
>  #define  DC_STATE_EN_DC9		(1<<3)
>  #define  DC_STATE_EN_UPTO_DC6		(2<<0)
>  #define  DC_STATE_EN_UPTO_DC5_DC6_MASK   0x3
> +#define  DC9_STATE			9
>  
>  #define  DC_STATE_DEBUG                  0x45520
>  #define  DC_STATE_DEBUG_MASK_MEMORY_UP	(1<<1)
> -- 
> 1.9.1
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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