Comment # 9 on bug 1184543 from Daike Yu

(In reply to Yifan Jiang from comment #8)
> > I think this make sense, but it seems I cannot reproduce it on 15.3 in VM.
> 
> Just to be sure - is it GNOME Live you were using for testing?

In this case (In reply to Alynx Zhou from comment #7)
> (In reply to Daike Yu from comment #3)
> > > Apr 08 21:04:44 linux.fritz.box gnome-shell[2646]: (EE) 3: /usr/bin/Xwayland (0x55f1d2361000+0x4faec) [0x55f1d23b0aec]
> > 
> > This is line 274 of xwl_glamor_gbm_get_wl_buffer_for_pixmap():
> > 
> > > (gdb) info line *0x4faec
> > > Line 274 of "xwayland-glamor-gbm.c"
> > >    starts at address 0x4faec <xwl_glamor_gbm_get_wl_buffer_for_pixmap+204>
> > >    and ends at 0x4faef <xwl_glamor_gbm_get_wl_buffer_for_pixmap+207>.
> > > (gdb) l xwl_glamor_gbm_get_wl_buffer_for_pixmap
> > > 256	}
> > > 257	
> > > 258	static struct wl_buffer *
> > > 259	xwl_glamor_gbm_get_wl_buffer_for_pixmap(PixmapPtr pixmap,
> > > 260	                                        Bool *created)
> > > 261	{
> > > 262	    struct xwl_screen *xwl_screen = xwl_screen_get(pixmap->drawable.pScreen);
> > > 263	    struct xwl_pixmap *xwl_pixmap = xwl_pixmap_get(pixmap);
> > > 264	    struct xwl_gbm_private *xwl_gbm = xwl_gbm_get(xwl_screen);
> > > 265	    unsigned short width = pixmap->drawable.width;
> > > (gdb) 
> > > 266	    unsigned short height = pixmap->drawable.height;
> > > 267	    int prime_fd;
> > > 268	    int num_planes;
> > > 269	    uint32_t strides[4];
> > > 270	    uint32_t offsets[4];
> > > 271	    uint64_t modifier;
> > > 272	    int i;
> > > 273	
> > > 274	    if (xwl_pixmap->buffer) {
> > > 275	        /* Buffer already exists. Return it and inform caller if interested. */
> > > (gdb) p &(((struct xwl_pixmap*)0)->buffer)
> > > $2 = (struct wl_buffer **) 0x0
> > > (gdb) 
> > 
> > which looks like
> > https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/47/
> > diffs?commit_id=036794bebce72a3fa2f95996d2e537ff568e0ff1 too, as in
> > boo#118072. Would you please also check if
> > https://build.opensuse.org/package/show/home:yudaike:branches:SUSE:SLE-15-
> > SP2:Update/xorg-x11-server makes any difference for you?
> > 
> > Thanks.
> 
> I think this make sense, but it seems I cannot reproduce it on 15.3 in VM.

xwl_pixmap_get() returns NULL if gbm_bo_create() fails, and the latter is
called into GPU driver. So this is likely a driver/hardware specific issue...