[PATCH xserver 1/2] prime: Sync shared pixmap from root window instead of screen pixmap

[Michel Dänzer]

On 01/02/17 06:35 PM, Michel Dänzer wrote:
> From: Michel Dänzer <michel.daenzer at amd.com>
> 
> The screen pixmap doesn't receive updates while there's a Present flip
> window.
> 
> Signed-off-by: Michel Dänzer <michel.daenzer at amd.com>
> ---
>  dix/pixmap.c | 16 ++++++++++++----
>  1 file changed, 12 insertions(+), 4 deletions(-)
> 
> diff --git a/dix/pixmap.c b/dix/pixmap.c
> index 49267a19b..ef0083083 100644
> --- a/dix/pixmap.c
> +++ b/dix/pixmap.c
> @@ -233,7 +233,8 @@ PixmapStartDirtyTracking(PixmapPtr src,
>      RegionUnion(damageregion, damageregion, &dstregion);
>      RegionUninit(&dstregion);
>  
> -    DamageRegister(&src->drawable, dirty_update->damage);
> +    DamageRegister(screen->root ? &screen->root->drawable : &src->drawable,
> +                   dirty_update->damage);

I discovered a problem with this. Looks like on server shutdown the
root window can be destroyed before the scanout pixmap is detached, see
valgrind output below.

Is there any solution for this other than wrapping DestroyWindow and
calling PixmapStopDirtyTracking when a root window is destroyed?


==32070== Invalid read of size 8
==32070==    at 0x23E20A: DamageDestroy (damage.c:1812)
==32070==    by 0x176560: PixmapStopDirtyTracking (pixmap.c:250)
==32070==    by 0x2190A6: RRCrtcDetachScanoutPixmap (rrcrtc.c:405)
==32070==    by 0x219147: RRCrtcDestroyResource (rrcrtc.c:883)
==32070==    by 0x17D296: doFreeResource (resource.c:880)
==32070==    by 0x17E49D: FreeClientResources (resource.c:1146)
==32070==    by 0x17E56B: FreeAllResources (resource.c:1161)
==32070==    by 0x15CA97: dix_main (main.c:303)
==32070==    by 0x6B5B2B0: (below main) (libc-start.c:291)
==32070==  Address 0x13f12f68 is 104 bytes inside a block of size 120 free'd
==32070==    at 0x4C2CDDB: free (vg_replace_malloc.c:530)
==32070==    by 0x23E357: damageDestroyWindow (damage.c:1567)
==32070==    by 0x1FD056: XvDestroyWindow (xvmain.c:385)
==32070==    by 0x1B293E: xf86XVDestroyWindow (xf86xv.c:1020)
==32070==    by 0x1EBDFB: compDestroyWindow (compwindow.c:607)
==32070==    by 0x18A2F4: FreeWindowResources (window.c:1031)
==32070==    by 0x18D577: DeleteWindow (window.c:1099)
==32070==    by 0x17D296: doFreeResource (resource.c:880)
==32070==    by 0x17E49D: FreeClientResources (resource.c:1146)
==32070==    by 0x17E56B: FreeAllResources (resource.c:1161)
==32070==    by 0x15CA97: dix_main (main.c:303)
==32070==    by 0x6B5B2B0: (below main) (libc-start.c:291)
==32070==  Block was alloc'd at
==32070==    at 0x4C2BBAF: malloc (vg_replace_malloc.c:299)
==32070==    by 0x1773C5: _dixAllocateObjectWithPrivates (privates.c:486)
==32070==    by 0x23DEE7: DamageCreate (damage.c:1699)
==32070==    by 0x17638A: PixmapStartDirtyTracking (pixmap.c:198)
==32070==    by 0x219D6D: rrSetupPixmapSharing (rrcrtc.c:591)
==32070==    by 0x219D6D: RRCrtcSet (rrcrtc.c:761)
==32070==    by 0x21AC53: ProcRRSetCrtcConfig (rrcrtc.c:1367)
==32070==    by 0x1588C8: Dispatch (dispatch.c:479)
==32070==    by 0x15CA64: dix_main (main.c:287)
==32070==    by 0x6B5B2B0: (below main) (libc-start.c:291)


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