From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48374) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zpdyr-0003n1-1E for qemu-devel@nongnu.org; Fri, 23 Oct 2015 11:10:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zpdyo-0001bc-39 for qemu-devel@nongnu.org; Fri, 23 Oct 2015 11:10:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45394) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zpdyn-0001Z6-VB for qemu-devel@nongnu.org; Fri, 23 Oct 2015 11:10:06 -0400 Date: Fri, 23 Oct 2015 16:26:55 +0100 From: Alexander Gordeev Message-ID: <20151023152654.GD29931@agordeev.usersys.redhat.com> References: <1445460229-7100-1-git-send-email-agordeev@redhat.com> <20151021220103.GB29931@agordeev.usersys.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [PATCH] hw/arm/virt: Fix address in PCIe device tree node's unit name List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell Cc: Andrew Jones , QEMU Developers On Fri, Oct 23, 2015 at 03:18:34PM +0100, Peter Maydell wrote: > On 21 October 2015 at 23:01, Alexander Gordeev wrote: > > On Wed, Oct 21, 2015 at 10:26:27PM +0100, Peter Maydell wrote: > >> On 21 October 2015 at 21:43, Alexander Gordeev wrote: > >> > PCIe device tree unit name is pcie@10000000 - which denotes > >> > IO space base address. However, the corresponding node's > >> > "reg" property points to PCI configuration space base address > >> > 0x3f000000. > >> > > >> > Set the unit name to pcie@3f000000 which is not only correct, > >> > but also conforms to Open Firmware (IEEE 1275). > >> > >> Nothing should actually care about the address in the > >> nodename, though, right -- it's just for human readability > >> and debugging (and guests will be looking at the regs > >> etc properties of the node to figure out where it is)? > >> Or have I misunderstood this and there's an actual visible > >> consequence to this bug? > > > > I do not think there are actual consequences out there. > > It is just misleading and does not honour the standard. > > Do you have a more precise reference than just "IEEE 1275" ? > I found the bit that says node names should be driver-name@unit-address, > and unit address is the "text representation of the physical address > of the device", but it seems to me that our current choice of > "the lowest physical address where you can find any part of this > device" is closer to that than deciding that we should use the > address of the config space window instead. No, I do not have it other than indirectly (though I probably could locate it). I relied on Linux Documentation/devicetree/bindings/pci/host-generic-pci.txt instead: - reg : The Configuration Space base address and size, as accessed from the parent bus. [...] IMHO it perfectly make sense - either io or memory mapped regions are rather used to map attached devices, while the unit name for a host bridge is implied to "address" the bridge itself, isn't it? Thanks! > thanks > -- PMM -- Regards, Alexander Gordeev agordeev@redhat.com