[RFC xserver v5 04/14] present: Send PresentCompleteModeSuboptimalCopy appropriately

[Michel Dänzer]

On 06/11/17 10:30 PM, Louis-Francis Ratté-Boulianne wrote:
> Add 'check_flip2' hook for driver to let know the core
> about why flipping is not possible ('reason').
> If it is because of unsupported buffer format/modifier,
> a PresentCompleteNotify event is sent to the client with
> the PresentCompleteModeSuboptimalCopy mode.
> 
> v2: Check for PresentOptionSuboptimal and check driver version
>     before using 'check_flip2'.
> 
> Signed-off-by: Louis-Francis Ratté-Boulianne <lfrb at collabora.com>

[...]

> @@ -177,7 +178,12 @@ present_check_flip(RRCrtcPtr    crtc,
>      }
>  
>      /* Ask the driver for permission */
> -    if (screen_priv->info->check_flip) {
> +    if (screen_priv->info->version >= 1 && screen_priv->info->check_flip2 && reason) {
> +        if (!(*screen_priv->info->check_flip2) (crtc, window, pixmap, sync_flip, reason)) {
> +            DebugPresent(("\td %08lx -> %08lx\n", window->drawable.id, pixmap ? pixmap->drawable.id : 0));
> +            return FALSE;
> +        }
> +    } else if (screen_priv->info->check_flip) {

This could be improved slightly in one of two ways:

The check_flip2 hook could be used even if reason is NULL. That way, the
driver could only provide the check_flip2 hook, it wouldn't need to
provide the check_flip hook as well.

Otherwise, the test could be rearranged as

    if (reason && screen_priv->info->version >= 1 && screen_priv->info->check_flip2) {

so that the screen_priv->info members don't need to be tested if reason
is NULL anyway.


> @@ -564,6 +570,7 @@ present_check_flip_window (WindowPtr window)
>      present_window_priv_ptr     window_priv = present_window_priv(window);
>      present_vblank_ptr          flip_pending = screen_priv->flip_pending;
>      present_vblank_ptr          vblank;
> +    int                         reason;

Either this local variable needs to be initialized, or
present_check_flip needs to set a reason value even if the driver
doesn't provide the check_flip2 hook.


> diff --git a/present/present.h b/present/present.h
> index aab2e168a..094946a7c 100644
> --- a/present/present.h
> +++ b/present/present.h
> @@ -27,6 +27,9 @@
>  #include "randrstr.h"
>  #include "presentext.h"
>  
> +#define PresentFlipReasonUnknown       0
> +#define PresentFlipReasonBufferFormat  1

Might be nice to make this an enum.


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer