From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Hans J. Koch" Subject: Re: [PATCH] uio_pci_generic does not export memory resources Date: Fri, 8 Jun 2012 17:18:43 +0200 Message-ID: <20120608151843.GA9705@local> References: <1339156616.3870.9.camel@blech> <20120608130351.GB1964@redhat.com> <1339165738.3870.18.camel@blech> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "Michael S. Tsirkin" , "Hans J. Koch" , Greg Kroah-Hartman , kvm@vger.kernel.org, linux-kernel@vger.kernel.org To: Dominic Eschweiler Return-path: Content-Disposition: inline In-Reply-To: <1339165738.3870.18.camel@blech> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On Fri, Jun 08, 2012 at 04:28:58PM +0200, Dominic Eschweiler wrote: > Am Freitag, den 08.06.2012, 16:03 +0300 schrieb Michael S. Tsirkin: > > Why is this needed? > > What's wrong with mapping resources through > > /sys/bus/pci/devices/XXXXXresourceX > > ? > > > Mmmh ok, the problem here is, that the UIO documentation states: > > "/dev/uioX is used to access the address space of the card. Just use > mmap() to access registers or RAM locations of your card." > > and > > "From userspace, the different mappings are distinguished by adjusting > the offset parameter of the mmap() call." > > > This does not work and the "/sys/class/uio/uioX/maps/mapX/" directories > do also not appear. Then there's something fundamentally wrong in your driver. Check the return value of uio_register_device(). > I was very confused when I tried UIO the first time > and it did not behave like it is described in the documentation. UIO is the mainline since 2007, and I can assure you it works like described. Lots of people use it. Try and fix your driver, then post it. If you absolutely don't get it working, post a non-working version for review. Thanks, Hans