From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757687Ab2IYTWT (ORCPT ); Tue, 25 Sep 2012 15:22:19 -0400 Received: from cavan.codon.org.uk ([93.93.128.6]:55132 "EHLO cavan.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753889Ab2IYTWS (ORCPT ); Tue, 25 Sep 2012 15:22:18 -0400 Date: Tue, 25 Sep 2012 20:22:11 +0100 From: Matthew Garrett To: Bjorn Helgaas Cc: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] PNP: Unbind drivers if the new driver matches _HID rather than _CID Message-ID: <20120925192211.GA24750@srcf.ucam.org> References: <1348579544-1573-1-git-send-email-mjg@redhat.com> <1348579544-1573-2-git-send-email-mjg@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: mjg59@cavan.codon.org.uk X-SA-Exim-Scanned: No (on cavan.codon.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 25, 2012 at 01:04:25PM -0600, Bjorn Helgaas wrote: > On Tue, Sep 25, 2012 at 7:25 AM, Matthew Garrett wrote: > Do you know of any scenarios besides this IPMI one where there's the > possibility of two drivers matching the same device? If so, does the > detach/attach process work reasonably? My worry is that drivers don't > normally give up devices, so the detach path is not well exercised. > And I don't know what happens to any users of the device during the > switch. For example, if something was using a TPM and we replaced the > driver, what does that look like to the user? Yeah, this could definitely happen with TPM - tpm_infinion could displace tpm_tis. This actually flags up something kind of obviously broken in the TPM code, since tpm_infineon comes *after* tpm_tis in the link order despite being more specific. Winning. It looks like there's a valid tpm_release function, but I'll find an infineon machine and figure out whether it actually works or not. -- Matthew Garrett | mjg59@srcf.ucam.org