From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Zyngier Subject: Re: [PATCH 1/2] vfio, platform: add support for ACPI while detecting the reset driver Date: Fri, 11 Mar 2016 04:05:37 +0000 Message-ID: <20160311040537.4067a210@arm.com> References: <1457451209-21462-1-git-send-email-okaya@codeaurora.org> <56E14858.9050401@linaro.org> <56E1AB38.8020702@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <56E1AB38.8020702-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Sinan Kaya Cc: Eric Auger , kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, timur-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, cov-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, jcm-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, shankerd-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, vikrams-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, vinod.koul-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, agross-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, linux-arm-msm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Baptiste Reynal , Alex Williamson , Dan Carpenter , Arnd Bergmann , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org On Thu, 10 Mar 2016 12:13:28 -0500 Sinan Kaya wrote: > On 3/10/2016 5:11 AM, Eric Auger wrote: > > Hi Sinan, > > On 03/08/2016 04:33 PM, Sinan Kaya wrote: > >> The code is using the compatible DT string to associate a reset driver with > >> the actual device itself. The compatible string does not exist on ACPI > >> based systems. HID is the unique identifier for a device driver instead. > >> The change allows a driver to register with DT compatible string or ACPI > >> HID and then match the object with one of these conditions. > >> > >> Rules for loading the reset driver are as follow: > >> - ACPI HID needs match for ACPI systems > >> - DT compat needs to match for OF systems > >> > >> Tested-by: Eric Auger (device tree only) > >> Tested-by: Shanker Donthineni (ACPI only) > >> Signed-off-by: Sinan Kaya > >> --- > >> .../vfio/platform/reset/vfio_platform_amdxgbe.c | 4 +- > >> .../platform/reset/vfio_platform_calxedaxgmac.c | 4 +- > >> drivers/vfio/platform/vfio_platform_common.c | 112 +++++++++++++++++---- > >> drivers/vfio/platform/vfio_platform_private.h | 43 ++++---- > >> 4 files changed, 125 insertions(+), 38 deletions(-) [...] > >> - vfio_platform_get_reset(vdev); > >> + ret = vfio_platform_get_reset(vdev); > >> + if (ret) { > >> + iommu_group_put(group); > >> + return ret; > >> + } > > This change is not related to your commit message. Also here you change > > the use model of VFIO platform and forbid any usage if no reset module > > is available, right? I don't think this is something we discussed and I > > think it removes some flexibility. Currently a warning is emitted in > > case we don't have a reset function. > > Well, I haven't seen that warning during testing. I was trying to be more > proactive. > > I'm fine removing these checks but not having a reset driver needs a really > big warning here. This code really needs to be moved to a separate patch, but I agree overall: a reset function should be made mandatory - I cannot imagine trusting the HW to be left in a sane state after being used by a guest. Thanks, M. -- Jazz is not dead. It just smells funny. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html