From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Matti Linnanvuori" Subject: Re: [PATCH v1.2.26] wan: new driver retina Date: Tue, 3 Jun 2008 15:08:32 +0300 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: jgarzik@pobox.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: "Krzysztof Halasa" Return-path: Received: from py-out-1112.google.com ([64.233.166.179]:51685 "EHLO py-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755069AbYFCMId (ORCPT ); Tue, 3 Jun 2008 08:08:33 -0400 Received: by py-out-1112.google.com with SMTP id p76so718905pyb.10 for ; Tue, 03 Jun 2008 05:08:32 -0700 (PDT) In-Reply-To: Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: 2008/5/30 Krzysztof Halasa : > "Matti Linnanvuori" writes: > >> I would not like to change a legacy driver much. > > But this is a new driver, right? I guess the SIOCDEVPRIVATEs will go > at some point so the change can't be really avoided. I posted retina-1.2.29.patch that does not have SIOCDEVPRIVATEs at http://groups.google.com/group/pcidriver/files. >>>> +static int fepci_char_open(struct inode *inode, struct file *filp) >>>> +{ >>>> + unsigned int minor = MINOR(inode->i_rdev); >>>> + if (unlikely(minor >= find_cnt || card_privates[minor].pci_dev == NULL)) >>>> + return -ENXIO; >>>> + filp->f_op = &fepci_char_fops; >>>> + if (unlikely(!try_module_get(THIS_MODULE))) >>>> + return -EBUSY; >>> >>> That won't work race-free, use owner field. >> >> You mean the f_op assignment? I have removed that. > > Actually I meant try_module_get() from within the driver, for example > your module may get unloaded while in this function, before this > try_module_get(), and that would be fatal. If you set the owner field > the reference count will be incremented by the caller first. I added the owner field setting to the above mentioned patch.