with CONFIG_GART_IOMMU enabled drivers/char/agp/amd64-agp.c has:
#ifndef CONFIG_GART_IOMMU
module_init(agp_amd64_init);
module_exit(agp_amd64_cleanup);
#endif
agp_amd64_init() was called via gart_iommu_init with
CONFIG_GART_IOMMU=y agp_amd64_init() was called via module_init
with CONFIG_GART_IOMMU=n
The commit 75f1cdf1dda92cae037ec848ae63690d91913eac changes the
x86 dma initialization routine: gart_iommu_init() is called only
when GART IOMMU is detected. So when GART IOMMU isn't detected,
agp_amd64_init isn't called.
Marin Mitov reported this issue:
http://marc.info/?l=linux-kernel&m=126192729110083&w=2
With this patch, agp_amd64_init() is always called via
module_init (the above ifndef is removed). If agp_amd64_init()
is called via gart_iommu_init() earlier, agp_amd64_init()
finishes without doing anything (when it is called via
module_init).
Reported-by: Marin Mitov <mitov@issp.bas.bg>
Tested-by: Marin Mitov <mitov@issp.bas.bg>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: davej@redhat.com
LKML-Reference: <20091228181118C.fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
f405d2c023