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Commit f405d2c0 authored by FUJITA Tomonori's avatar FUJITA Tomonori Committed by Ingo Molnar
Browse files

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 75f1cdf1 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: default avatarMarin Mitov <mitov@issp.bas.bg>
Tested-by: default avatarMarin Mitov <mitov@issp.bas.bg>
Signed-off-by: default avatarFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: davej@redhat.com
LKML-Reference: <20091228181118C.fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 39d30770

drivers/char/agp/amd64-agp.c

+5 −4
Original line number Diff line number Diff line
@@ -725,9 +725,14 @@ static struct pci_driver agp_amd64_pci_driver = { 
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 @@ static void __exit agp_amd64_cleanup(void) 
	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);