(aside - whats the correct ML? Ive used both suggested by my mail interface) I have 2 modules with same modinfo alias, one installs, the other gets -ENODEV. Id expect them to both act the same. What am I missing ? root@voyage:~# modprobe geode-aes root@voyage:~# lsmod |grep geode_aes geode_aes 4229 0 root@voyage:~# modprobe geode-rng dynamic_debug:ddebug_remove_module: removing module "geode_rng" FATAL: Error inserting geode_rng (/lib/modules/3.0.0-skc-dyndbg+/kernel/drivers/char/hw_random/geode-rng.ko): No such device root@voyage:~# modinfo geode-aes filename: /lib/modules/3.0.0-skc-dyndbg+/kernel/drivers/crypto/geode-aes.ko license: GPL description: Geode LX Hardware AES driver author: Advanced Micro Devices, Inc. alias: pci:v00001022d00002082sv*sd*bc*sc*i* depends: vermagic: 3.0.0-skc-dyndbg+ preempt mod_unload modversions GEODEGX1 root@voyage:~# modinfo geode-rng filename: /lib/modules/3.0.0-skc-dyndbg+/kernel/drivers/char/hw_random/geode-rng.ko license: GPL description: H/W RNG driver for AMD Geode LX CPUs alias: pci:v00001022d00002082sv*sd*bc*sc*i* depends: rng-core vermagic: 3.0.0-skc-dyndbg+ preempt mod_unload modversions GEODEGX1 IE both have same alias, and (unsurprisingly) the same DEVICE_ID. geode-rng's 1 dependency isnt the problem: root@voyage:~# modprobe rng-core root@voyage:~# lsmod |grep rng rng_core 3010 0 DEVICE-IDs: jimc@chumly:~/projects/lx/linux-2.6/drivers/crypto$ grep PCI_DEV geode-aes.c { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_LX_AES), } , jimc@chumly:~/projects/lx/linux-2.6/drivers/crypto$ cd ../char/hw_random/ jimc@chumly:~/projects/lx/linux-2.6/drivers/char/hw_random$ grep PCI_DEV geode-rng.c { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_LX_AES), 0, }, hmmm. is that trailing 0 important ? Id think not, {..} is a literal constant assignment, 0 is only sensible default. The apparent diff is how the __init is done. static struct pci_device_id geode_aes_tbl[] = { { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_LX_AES), } , { 0, } }; MODULE_DEVICE_TABLE(pci, geode_aes_tbl); static struct pci_driver geode_aes_driver = { .name = "Geode LX AES", .id_table = geode_aes_tbl, .probe = geode_aes_probe, .remove = __devexit_p(geode_aes_remove) }; static int __init geode_aes_init(void) { return pci_register_driver(&geode_aes_driver); } geode-rng does it the (older?) more manual way: static int __init mod_init(void) { int err = -ENODEV; struct pci_dev *pdev = NULL; const struct pci_device_id *ent; void __iomem *mem; unsigned long rng_base; for_each_pci_dev(pdev) { ent = pci_match_id(pci_tbl, pdev); if (ent) goto found; } /* Device not found. */ goto out; found: ... Qs 1 - why do they differ in modprobe results ? bug likely ?? 2 - which is correct ? success or failure ? FWIW, heres my PCI devices. The CPU is an SC1100 - its a Geode, but not a Geode-GX or LX (though the distinctions arent as clear as Id like :-/) root@voyage:~# lspci -nn 00:00.0 Host bridge [0600]: Cyrix Corporation PCI Master [1078:0001] 00:06.0 Ethernet controller [0200]: National Semiconductor Corporation DP83815 (MacPhyter) Ethernet Controller [100b:0020] 00:07.0 Ethernet controller [0200]: National Semiconductor Corporation DP83815 (MacPhyter) Ethernet Controller [100b:0020] 00:08.0 Ethernet controller [0200]: National Semiconductor Corporation DP83815 (MacPhyter) Ethernet Controller [100b:0020] 00:0a.0 Ethernet controller [0200]: Belkin Wireless PCI Card - F5D6001 [1799:6001] (rev 20) 00:0e.0 Ethernet controller [0200]: Marvell Technology Group Ltd. 88W8361 [TopDog] 802.11n Wireless [11ab:2a02] (rev 03) 00:12.0 ISA bridge [0601]: National Semiconductor Corporation SC1100 Bridge [100b:0510] 00:12.1 Bridge [0680]: National Semiconductor Corporation SC1100 SMI & ACPI [100b:0511] 00:12.2 IDE interface [0101]: National Semiconductor Corporation SCx200, SC1100 IDE controller [100b:0502] (rev 01) 00:12.5 Bridge [0680]: National Semiconductor Corporation SC1100 XBus [100b:0515] 00:13.0 USB Controller [0c03]: Compaq Computer Corporation ZFMicro Chipset USB [0e11:a0f8] (rev 08) Specifically, theres no AMD ID in the output root@voyage:~# lspci -nn |grep 1022 root@voyage:~# lspci -nn |grep 100b 00:06.0 Ethernet controller [0200]: National Semiconductor Corporation DP83815 (MacPhyter) Ethernet Controller [100b:0020]

From all this, it seems that the failure to install is correct, which suggests some bug in pci_register_driver, but its hard to imagine that - otherwize its survived (well hidden) for a long time