[PATCH 1/2] dri2: Let client call swap before previous swap target has been passed

[walter harms]

Am 29.08.2011 13:45, schrieb Pauli Nieminen:
> From: Pauli Nieminen <pauli.nieminen at linux.intel.com>
> 
> Client has to be allowed to call swap buffers before last_swap_target
> has been passed if driver implements triple buffering with
> swap_interval.
> 
> Time that swap may come before reaching last_swap_target is swap_limit *
> swap_interval if application renders very fast until throttled.
> 
> Signed-off-by: Pauli Nieminen <pauli.nieminen at linux.intel.com>
> ---
>  hw/xfree86/dri2/dri2.c |   21 +++++++++++++++++++--
>  1 files changed, 19 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/xfree86/dri2/dri2.c b/hw/xfree86/dri2/dri2.c
> index af3bcae..44a8348 100644
> --- a/hw/xfree86/dri2/dri2.c
> +++ b/hw/xfree86/dri2/dri2.c
> @@ -791,6 +791,14 @@ DRI2WaitSwap(ClientPtr client, DrawablePtr pDrawable)
>      return FALSE;
>  }
>  
> +#ifndef WORD64
> +# ifdef LONG64
> +typedef long INT64;
> +# else
> +typedef long long INT64;
> +#endif
> +#endif
> +


hi,
maybe it is better to use int64_t to have 64bit granted instead of making it ?

re,
 wh



>  int
>  DRI2SwapBuffers(ClientPtr client, DrawablePtr pDraw, CARD64 target_msc,
>  		CARD64 divisor, CARD64 remainder, CARD64 *swap_target,
> @@ -854,12 +862,21 @@ DRI2SwapBuffers(ClientPtr client, DrawablePtr pDraw, CARD64 target_msc,
>  	 * got enabled.
>  	 */
>  	if (ds->GetMSC) {
> +	    INT64 msc_diff;
> +	    INT64 future_frames_allowed = pPriv->swap_limit * pPriv->swap_interval;
>  	    if (!(*ds->GetMSC)(pDraw, &ust, &current_msc))
>  		pPriv->last_swap_target = 0;
>  
> -	    if (current_msc < pPriv->last_swap_target)
> -		pPriv->last_swap_target = current_msc;
> +	    msc_diff = (INT64)pPriv->last_swap_target - (INT64)current_msc;
>  
> +	    /*
> +	     * If current_msc is more than swap_limit * swap_interval in future
> +	     * assume there was CRTC switch. That requires fixing swap_target for
> +	     * driver.
> +	     */
> +	    if (msc_diff < future_frames_allowed)
> +		pPriv->last_swap_target = current_msc
> +			+ pPriv->swapsPending * pPriv->swap_interval;
>  	}
>  
>  	/*