From f405d2c02395a74d3883bd03ded36457aa3697ad Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Mon, 28 Dec 2009 18:11:56 +0900 Subject: [PATCH] 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 Tested-by: Marin Mitov Signed-off-by: FUJITA Tomonori Cc: davej@redhat.com LKML-Reference: <20091228181118C.fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Ingo Molnar --- drivers/char/agp/amd64-agp.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/char/agp/amd64-agp.c b/drivers/char/agp/amd64-agp.c index 2fb2e6cc322a..5aa7a586a7ff 100644 --- a/drivers/char/agp/amd64-agp.c +++ b/drivers/char/agp/amd64-agp.c @@ -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 , Andi Kleen"); module_param(agp_try_unsupported, bool, 0); -- 2.34.1