#9636: Remove PRIME support patch in Xorg server
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Reporter: pierre.labastie | Owner: blfs-book@…
Type: defect | Status: new
Priority: normal | Milestone: 8.1
Component: BOOK | Version: SVN
Severity: normal | Resolution:
Keywords: |
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Comment (by pierre.labastie):
I do not know how many users have really tried to use a dual card system.
To me there is a fundamental flaw in the patch. The function
''xf86AutoConfigOutputDevice'' contains the sequence:
{{{
DetachUnboundGPU(pScrn->pScreen);
AttachOffloadGPU(master->pScreen, pScrn->pScreen);
}}}
Now ''DetachUnboundGPU'' (in xorg-server-source/dix/dispatch.c) contains:
{{{
void
DetachUnboundGPU(ScreenPtr slave)
{
/*...*/
xorg_list_del(&slave->slave_head);
slave->current_master = NULL;
}
}}}
so that ''pScrn->pScreen->current_master = NULL'' after this call.
Now ''AttachOffloadGPU'' (same source) contains:
{{{
void
AttachOffloadGPU(ScreenPtr pScreen, ScreenPtr new)
{
assert(new->isGPU);
assert(!new->is_offload_slave);
assert(new->current_master == pScreen);
/*...*/
}
}}}
So that ''new->current_master'' is NULL and not pScreen!
Reading the source of dispatch.c, I think that AttachOutputGPU should be
called before AttachOffloadGPU. But I need some confirmation.
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Ticket URL: <http://wiki.linuxfromscratch.org/blfs/ticket/9636#comment:3>
BLFS Trac <http://wiki.linuxfromscratch.org/blfs>
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