From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40729) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YBgQI-0008AK-MY for qemu-devel@nongnu.org; Thu, 15 Jan 2015 04:09:03 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YBgQF-0004Mm-HI for qemu-devel@nongnu.org; Thu, 15 Jan 2015 04:09:02 -0500 Received: from mx1.redhat.com ([209.132.183.28]:35096) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YBgQF-0004Mg-9R for qemu-devel@nongnu.org; Thu, 15 Jan 2015 04:08:59 -0500 Message-ID: <54B7839E.5020903@redhat.com> Date: Thu, 15 Jan 2015 10:08:46 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <1420948672-50103-1-git-send-email-sfeldma@gmail.com> <1420948672-50103-7-git-send-email-sfeldma@gmail.com> <54B3C4C6.2000703@redhat.com> In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v3 6/9] rocker: add new rocker switch device List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Scott Feldman Cc: =?UTF-8?B?SmnFmcOtIFDDrXJrbw==?= , Stefan Hajnoczi , Roopa Prabhu , john fastabend , QEMU Developers On 15/01/2015 00:20, Scott Feldman wrote: > I tried setting .impl.max_access_size=4 and the Linux driver self-test > fails on 64-bit reg write/read. 32-bit regs writes/reads are OK. On > the 64-bit write/read, the self test writes a value and expects to > read back 2x the value written. After making the change > .impl.max_access_size=4, the reg reads back as 0, regardless of what > was written. It would be a bug. I can try to look at it later. Paolo > The driver uses writeq/readq for 64-bit writes/reads. > > I'm inclined to not change the device and leave .impl.max_access_size=8.