From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Auger Subject: Re: [PATCH V2 2/3] vfio, platform: make reset driver a requirement Date: Sun, 27 Mar 2016 17:21:50 +0200 Message-ID: <56F7FA8E.9000707@linaro.org> References: <1457715275-11925-1-git-send-email-okaya@codeaurora.org> <1457715275-11925-3-git-send-email-okaya@codeaurora.org> <56E5A271.6000408@codeaurora.org> <56E8E2CD.3020604@linaro.org> <56E96D4C.3080008@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-wm0-f47.google.com ([74.125.82.47]:37090 "EHLO mail-wm0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752141AbcC0PW6 (ORCPT ); Sun, 27 Mar 2016 11:22:58 -0400 Received: by mail-wm0-f47.google.com with SMTP id p65so72847702wmp.0 for ; Sun, 27 Mar 2016 08:22:58 -0700 (PDT) In-Reply-To: <56E96D4C.3080008@codeaurora.org> Sender: linux-arm-msm-owner@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org To: Sinan Kaya , kvm@vger.kernel.org, timur@codeaurora.org, cov@codeaurora.org, jcm@redhat.com, Baptiste Reynal Cc: shankerd@codeaurora.org, vikrams@codeaurora.org, marc.zyngier@arm.com, mark.rutland@arm.com, devicetree@vger.kernel.org, vinod.koul@intel.com, agross@codeaurora.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Alex Williamson , linux-kernel@vger.kernel.org Hi Sinan, On 03/16/2016 03:27 PM, Sinan Kaya wrote: > Hi Baptiste, > >>> I couldn't see a reset function for AMBA devices. >>> >>> Is there anyway to write reset function for it? I have no experience with >>> AMBA devices. >> To my knowledge only the PL330 DMA controller (drivers/dma/pl330.c) was >> passthrough'ed at some point, rather for development purpose than >> production purpose. This was done by Virtual Open Systems (ask Baptiste >> for more details). But I don't think this is really used. > > Are you OK with requiring reset driver for AMBA devices too? The PL330 > driver won't work until a reset driver is submitted for it. > >>> >>> Would you include a reset needed flag and just not require it for AMBA? >>> (I honestly don't like this idea) >>> >> I think the requirement also makes sense for AMBA. >> >> Maybe an option would be to add a module parameter that would allow to >> use the vfio platform/amba driver without reset module (with explicit >> opt-in from the user). Maybe this can be done later on. > > I can see this flag useful for testing purposes but it should not be used in > production. > > How about I add a module parameter which is not set by default? When set, > I don't perform the reset requirement check. Yes that's what I meant Best Regards Eric > >> >> FYI I will not have access to my mailbox until the end of the week. > > OK, no rush. > >> >> Best Regards >> >> Eric >> > >