From 307d114441f905e4576871ff28d06408a1af1a7e Mon Sep 17 00:00:00 2001 From: Jarkko Lavinen Date: Mon, 1 Dec 2008 13:14:06 -0800 Subject: i82875p_edac: fix overflow device resource setup When I do "modprobe i82875p_edac" on my Asus P4C800 MB on kernels 2.6.26 or later, the module load fails due to BAR 0 collision. On 2.6.25 the module loads just fine. The overflow device on the MB seems to be hidden and its resources are not allocated at normal PCI bus init. Log shows the missing resource problem: EDAC DEBUG: i82875p_probe1() PCI: 0000:00:06.0 reg 10 32bit mmio: [fecf0000, fecf0fff] pci 0000:00:06.0: device not available because of BAR 0 [0xfecf0000-0xfecf0fff] collisions EDAC i82875p: i82875p_setup_overfl_dev(): Failed to enable overflow device The patch below fixes this by calling pci_bus_assign_resources() after the overflow device is revealed and added to the bus. With this patch I am again able to load and use the module. Signed-off-by: Jarkko Lavinen Cc: Doug Thompson Cc: Jesse Barnes Cc: Alan Cox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/edac/i82875p_edac.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/edac/i82875p_edac.c') diff --git a/drivers/edac/i82875p_edac.c b/drivers/edac/i82875p_edac.c index e43bdc43a1b..7f909972fec 100644 --- a/drivers/edac/i82875p_edac.c +++ b/drivers/edac/i82875p_edac.c @@ -295,6 +295,7 @@ static int i82875p_setup_overfl_dev(struct pci_dev *pdev, "%s(): pci_bus_add_device() Failed\n", __func__); } + pci_bus_assign_resources(dev->bus); } *ovrfl_pdev = dev; -- cgit v1.2.3 From 09a81269c7aadaec3375a7ebd9647acbb72f5a67 Mon Sep 17 00:00:00 2001 From: Jarkko Lavinen Date: Mon, 1 Dec 2008 13:14:08 -0800 Subject: i82875p_edac: fix module remove Fix module removal bugs of i82875p_edac. Also i82975x_edac code seems to have the same module removal bugs as in i82875p_edac. The problems were: 1. In module removal i82875p_remove_one() is never called. Variable i82875p_registered is newer changed from 1, which guarantees i82875p_remove_one() is not called (and even if it were called, it would be called in wrong order). As a result, the edac_mc workque is not stopped and keeps probing. If kernel debugging options are not enabled, user may not notice anything going wrong. if debugging options are enabled and I do "rmmod i82875p_edac", I get: edac debug: edac_pci_workq_function() checking BUG: unable to handle kernel paging request at f882d16f ... call trace: [] ? edac_mc_workq_function+0x55/0x7e [edac_core] [] ? run_workqueue+0xd7/0x1a5 [] ? run_workqueue+0x92/0x1a5 [] ? edac_mc_workq_function+0x0/0x7e [edac_core] [] ? worker_thread+0xb7/0xc3 [] ? autoremove_wake_function+0x0/0x33 [] ? worker_thread+0x0/0xc3 [] ? kthread+0x3b/0x61 [] ? kthread+0x0/0x61 [] ? kernel_thread_helper+0x7/0x10 Fix for this is to get rid of needles variable i82875p_registered altogether and run i82875p_remove_one() *before* pci_unregister_driver(). 2. edac_mc_del_mc() uses mci after freeing mci edac_mc_del_mc() calls calls edac_remove_sysfs_mci_device(). The kobject refcount of mci drops to 0 and mci is freed. After this mci is accessed via debug print and i82875p_remove_one() still uses mci->pvt and tries to free mci again with edac_mc_free(). The fix for this is add kobject_get(&mci->edac_mci_kobj) after edac_mc_alloc(). Then the mci is still available after returning from edac_mc_del_mc() with refcount 1, and mci->pvt is still available. When i82875p_remove_one() finally calls edac_mc_free(), this will cause kobject_put() and mci is released properly. Signed-off-by: Jarkko Lavinen Cc: Doug Thompson Cc: Alan Cox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/edac/i82875p_edac.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'drivers/edac/i82875p_edac.c') diff --git a/drivers/edac/i82875p_edac.c b/drivers/edac/i82875p_edac.c index 7f909972fec..ebb037b7875 100644 --- a/drivers/edac/i82875p_edac.c +++ b/drivers/edac/i82875p_edac.c @@ -182,8 +182,6 @@ static struct pci_dev *mci_pdev; /* init dev: in case that AGP code has * already registered driver */ -static int i82875p_registered = 1; - static struct edac_pci_ctl_info *i82875p_pci; static void i82875p_get_error_info(struct mem_ctl_info *mci, @@ -410,6 +408,9 @@ static int i82875p_probe1(struct pci_dev *pdev, int dev_idx) goto fail0; } + /* Keeps mci available after edac_mc_del_mc() till edac_mc_free() */ + kobject_get(&mci->edac_mci_kobj); + debugf3("%s(): init mci\n", __func__); mci->dev = &pdev->dev; mci->mtype_cap = MEM_FLAG_DDR; @@ -452,6 +453,7 @@ static int i82875p_probe1(struct pci_dev *pdev, int dev_idx) return 0; fail1: + kobject_put(&mci->edac_mci_kobj); edac_mc_free(mci); fail0: @@ -579,12 +581,11 @@ static void __exit i82875p_exit(void) { debugf3("%s()\n", __func__); + i82875p_remove_one(mci_pdev); + pci_dev_put(mci_pdev); + pci_unregister_driver(&i82875p_driver); - if (!i82875p_registered) { - i82875p_remove_one(mci_pdev); - pci_dev_put(mci_pdev); - } } module_init(i82875p_init); -- cgit v1.2.3