x86/agp: Fix agp_amd64_init() initialization with CONFIG_GART_IOMMU enabled
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>
diff --git a/drivers/char/agp/amd64-agp.c b/drivers/char/agp/amd64-agp.c
index 2fb2e6c..5aa7a58 100644
--- a/drivers/char/agp/amd64-agp.c
+++ b/drivers/char/agp/amd64-agp.c
@@ -725,9 +725,14 @@
int __init agp_amd64_init(void)
{
int err = 0;
+ static int done = 0;
if (agp_off)
return -EINVAL;
+
+ if (done++)
+ return agp_bridges_found ? 0 : -ENODEV;
+
err = pci_register_driver(&agp_amd64_pci_driver);
if (err < 0)
return err;
@@ -771,12 +776,8 @@
pci_unregister_driver(&agp_amd64_pci_driver);
}
-/* On AMD64 the PCI driver needs to initialize this driver early
- for the IOMMU, so it has to be called via a backdoor. */
-#ifndef CONFIG_GART_IOMMU
module_init(agp_amd64_init);
module_exit(agp_amd64_cleanup);
-#endif
MODULE_AUTHOR("Dave Jones <davej@redhat.com>, Andi Kleen");
module_param(agp_try_unsupported, bool, 0);
