[PATCH 2/2] drm: Add DRM_DEBUG_VBL()

[Daniel Vetter]

On Fri, Oct 09, 2015 at 10:57:37PM +0300, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Add a new debug class for _verbose_ debug message from the vblank code.
> That is message we spew out potentially for every vblank interrupt.
> Thierry already got annoyed at the spew, and now I managed to lock up
> my box with these debug prints (seems serial console + a few debug
> prints every vblank aren't a good combination).
> 
> Or should I maybe call it DRM_DEBUG_IRQ?

I like _VBL since that's what this is about. The irq helpers are really,
really tiny in drm_irq.c and mostly just here for *bsd/linux abstraction
i.e. historical reasons.

Both patches applied to drm-misc.

Thanks, Daniel
> 
> Cc: Thierry Reding <thierry.reding at gmail.com>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/drm_irq.c | 22 +++++++++++-----------
>  include/drm/drmP.h        | 11 ++++++++++-
>  2 files changed, 21 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
> index bc2e7c6..eba6337 100644
> --- a/drivers/gpu/drm/drm_irq.c
> +++ b/drivers/gpu/drm/drm_irq.c
> @@ -213,17 +213,17 @@ static void drm_update_vblank_count(struct drm_device *dev, unsigned int pipe,
>  		diff = DIV_ROUND_CLOSEST_ULL(diff_ns, framedur_ns);
>  
>  		if (diff == 0 && flags & DRM_CALLED_FROM_VBLIRQ)
> -			DRM_DEBUG("crtc %u: Redundant vblirq ignored."
> -				  " diff_ns = %lld, framedur_ns = %d)\n",
> -				  pipe, (long long) diff_ns, framedur_ns);
> +			DRM_DEBUG_VBL("crtc %u: Redundant vblirq ignored."
> +				      " diff_ns = %lld, framedur_ns = %d)\n",
> +				      pipe, (long long) diff_ns, framedur_ns);
>  	} else {
>  		/* some kind of default for drivers w/o accurate vbl timestamping */
>  		diff = (flags & DRM_CALLED_FROM_VBLIRQ) != 0;
>  	}
>  
> -	DRM_DEBUG("updating vblank count on crtc %u:"
> -		  " current=%u, diff=%u, hw=%u hw_last=%u\n",
> -		  pipe, vblank->count, diff, cur_vblank, vblank->last);
> +	DRM_DEBUG_VBL("updating vblank count on crtc %u:"
> +		      " current=%u, diff=%u, hw=%u hw_last=%u\n",
> +		      pipe, vblank->count, diff, cur_vblank, vblank->last);
>  
>  	if (diff == 0) {
>  		WARN_ON_ONCE(cur_vblank != vblank->last);
> @@ -800,11 +800,11 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
>  		etime = ktime_sub_ns(etime, delta_ns);
>  	*vblank_time = ktime_to_timeval(etime);
>  
> -	DRM_DEBUG("crtc %u : v 0x%x p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
> -		  pipe, vbl_status, hpos, vpos,
> -		  (long)tv_etime.tv_sec, (long)tv_etime.tv_usec,
> -		  (long)vblank_time->tv_sec, (long)vblank_time->tv_usec,
> -		  duration_ns/1000, i);
> +	DRM_DEBUG_VBL("crtc %u : v 0x%x p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
> +		      pipe, vbl_status, hpos, vpos,
> +		      (long)tv_etime.tv_sec, (long)tv_etime.tv_usec,
> +		      (long)vblank_time->tv_sec, (long)vblank_time->tv_usec,
> +		      duration_ns/1000, i);
>  
>  	return ret;
>  }
> diff --git a/include/drm/drmP.h b/include/drm/drmP.h
> index 3dc56d3..4d3b842 100644
> --- a/include/drm/drmP.h
> +++ b/include/drm/drmP.h
> @@ -107,6 +107,9 @@ struct dma_buf_attachment;
>   * ATOMIC: used in the atomic code.
>   *	  This is the category used by the DRM_DEBUG_ATOMIC() macro.
>   *
> + * VBL: used for verbose debug message in the vblank code
> + *	  This is the category used by the DRM_DEBUG_VBL() macro.
> + *
>   * Enabling verbose debug messages is done through the drm.debug parameter,
>   * each category being enabled by a bit.
>   *
> @@ -114,7 +117,7 @@ struct dma_buf_attachment;
>   * drm.debug=0x2 will enable DRIVER messages
>   * drm.debug=0x3 will enable CORE and DRIVER messages
>   * ...
> - * drm.debug=0xf will enable all messages
> + * drm.debug=0x3f will enable all messages
>   *
>   * An interesting feature is that it's possible to enable verbose logging at
>   * run-time by echoing the debug value in its sysfs node:
> @@ -125,6 +128,7 @@ struct dma_buf_attachment;
>  #define DRM_UT_KMS		0x04
>  #define DRM_UT_PRIME		0x08
>  #define DRM_UT_ATOMIC		0x10
> +#define DRM_UT_VBL		0x20
>  
>  extern __printf(2, 3)
>  void drm_ut_debug_printk(const char *function_name,
> @@ -217,6 +221,11 @@ void drm_err(const char *format, ...);
>  		if (unlikely(drm_debug & DRM_UT_ATOMIC))		\
>  			drm_ut_debug_printk(__func__, fmt, ##args);	\
>  	} while (0)
> +#define DRM_DEBUG_VBL(fmt, args...)					\
> +	do {								\
> +		if (unlikely(drm_debug & DRM_UT_VBL))			\
> +			drm_ut_debug_printk(__func__, fmt, ##args);	\
> +	} while (0)
>  
>  /*@}*/
>  
> -- 
> 2.4.9
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch