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Date: Mon, 12 Oct 2015 21:05:46 +0000 (UTC)
From: Keith Busch <keith.busch@intel.com>
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To: Bjorn Helgaas <helgaas@kernel.org>
cc: Keith Busch <keith.busch@intel.com>, LKML <linux-kernel@vger.kernel.org>,
        x86@kernel.org, linux-pci@vger.kernel.org,
        Jiang Liu <jiang.liu@linux.intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Dan Williams <dan.j.williams@intel.com>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Bryan Veal <bryan.e.veal@intel.com>, Ingo Molnar <mingo@redhat.com>,
        "H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [RFC PATCHv2] x86/pci: Initial commit for new VMD device
 driver
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On Tue, 6 Oct 2015, Bjorn Helgaas wrote:
>> +static int __init vmd_init(void)
>> +{
>> +	return pci_register_driver(&vmd_drv);
>> +}
>> +module_init(vmd_init);
>
> module_pci_driver(vmd_drv)?

We actually only have a module_init in this driver, and purposely left
out module_exit. We don't want to be able to unload this because we
can't reference count this module for modules depending on it.

'rmmod <module>' returns busy if you're actively using a device that
module is driving, but the end devices VMD provides are not driven by the
VMD driver; it'd be kind of like being able to unload the pci core driver.