[meta-freescale] xf86-video-imxfb-vivante crashing with Xorg 1.19

[Gary Thomas]

When I build for my i.MX6Q target, X crashes immediately.  This is a
direct result of OE-core updating the X server from 1.18.4 to 1.19
What I've been able to discover is that the video driver (xf86-video-imxfb-vivante)
is being called early on from 'AddScreen' in the main X server.  The
driver sets up a shared data structure DRIInfoRec like this:

VivDRIScreenInit: pDRIInfo: 0xb76e80, busIdString = 0xb76f38 ('platform:Vivante GCCore:00')
00B76E80: 0000 0000 0000 0000  0000 0000 0000 0000   |................|
00B76E90: 0000 0000 0000 0000  0000 0000 0000 0000   |................|
00B76EA0: 0000 0000 0000 0000  9401 1500 3C03 1500   |............<...|
00B76EB0: 9CCF 1400 B0D1 1400  1404 1500 38D3 1400   |............8...|
00B76EC0: B0D6 59B6 B8D6 59B6  386F B700 0000 0000   |..Y...Y.8o......|
00B76ED0: 0000 0000 0000 0000  0000 0000 0000 0000   |................|
00B76EE0: 0000 0000 0000 0000  0000 0000 0000 0000   |................|
00B76EF0: 0000 0000 0000 0000  0000 0000 0000 0000   |................|
00B76F00: 0000 0000 0000 0000  0000 0000 0000 0000   |................|
00B76F10: 0000 0000 0000 0000  0000 0000 0000 0000   |................|
00B76F20: 0000 0000 0000 0000  0000 0000 0000 0000   |................|

but by the time the server gets to ProcXF86DRIOpenConnection, this structure
has been trashed:

DRIOpenConnection: pDRIPriv: 0xb76fc0, pDriverInfo: 0xb76e80, busIdString: 0x454d
00B76E80: E889 B700 C06E B700  0000 0000 0400 0000   |.....n..........|
00B76E90: FFFF FF7F FFFF FFFF  0000 0080 0000 0000   |................|
00B76EA0: 0200 0000 9018 0D00  DC18 0D00 0000 0000   |................|
00B76EB0: 2075 1D00 B88B B700  0000 0000 1100 0000   | u..............|
00B76EC0: 5345 5256 4552 5449  4D45 0000 2900 0000   |SERVERTIME..)...|
00B76ED0: 0000 0000 0000 0000  4C00 0000 00EC B000   |........L.......|
00B76EE0: 0000 0000 0000 0000  A95D 1A00 888B B700   |.........]......|
00B76EF0: 0100 0000 1900 0000  0000 0000 4C00 0000   |............L...|
00B76F00: 1600 0000 D06E B700  1800 0000 3900 0000   |.....n......9...|
00B76F10: 0100 0000 0000 0000  486F B700 8100 0000   |........Ho......|
00B76F20: 4000 0000 4100 0000  0000 0000 0000 0000   |@...A...........|
ProcXF86DRIOpenConnection: busIdString = 0x454d

I'm pretty sure that what's happening is near the end of AddScreen,
there is a call to dixRegisterScreenPrivateKey() which in turn
calls dixReallocPrivates() which seems to be relocating the DRIInfoRec
but the pointers used by DRIOpenConnection() are not updated.  The old
(non-relocated) structure gets reused and trashed and when DRIOpenConnection()
it picks up garbage.

I'm not sure what needs to change to fix this though.  Looking at the X server
code, I didn't find a lot of differences in/around this code path.  What I do
know is that reverting to xserver-xorg 1.18.4 absolutely works.

I'm using Poky/Yocto + meta-freescale layers (both on master)
   poky: 840e221ea7c35177fda37af618c4727fa7754789
   meta-freescale: a99b95c899e6c20b9f46fa04766c155e3a32949a

Has anyone else built X (not Wayland) recently using this codebase?  Anyone
else having the same issues?

Thanks

-- 
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Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
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