From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751629AbeBWOtv (ORCPT ); Fri, 23 Feb 2018 09:49:51 -0500 Received: from mail-lf0-f45.google.com ([209.85.215.45]:40943 "EHLO mail-lf0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751406AbeBWOtt (ORCPT ); Fri, 23 Feb 2018 09:49:49 -0500 X-Google-Smtp-Source: AH8x225Ihz84w0P/2NsbTZn+17dcP5IaL7QS4nn8epen8yIfUUkD1hNsu7AH85Issn7/aO0CfDC76Q== Subject: Re: [PATCH 4/9] drm/xen-front: Implement Xen event channel handling To: Boris Ostrovsky , xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, airlied@linux.ie, daniel.vetter@intel.com, seanpaul@chromium.org, gustavo@padovan.org, jgross@suse.com, konrad.wilk@oracle.com Cc: Oleksandr Andrushchenko References: <1519200222-20623-1-git-send-email-andr2000@gmail.com> <1519200222-20623-5-git-send-email-andr2000@gmail.com> <395cdaef-db7e-139c-bbf1-28cb33f41f58@oracle.com> <5145287f-40b0-c8e2-1b37-36d7e8cac908@gmail.com> <7d8ab151-e90d-baef-93b6-8ca1c7e42908@oracle.com> From: Oleksandr Andrushchenko Message-ID: <63c64a2f-211e-2f62-21e7-289f0cc69df0@gmail.com> Date: Fri, 23 Feb 2018 16:49:46 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <7d8ab151-e90d-baef-93b6-8ca1c7e42908@oracle.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/23/2018 04:44 PM, Boris Ostrovsky wrote: > On 02/23/2018 02:00 AM, Oleksandr Andrushchenko wrote: >> On 02/23/2018 01:50 AM, Boris Ostrovsky wrote: >>> On 02/21/2018 03:03 AM, Oleksandr Andrushchenko wrote: >>>> + >>>> +static irqreturn_t evtchnl_interrupt_ctrl(int irq, void *dev_id) >>>> +{ >>>> + struct xen_drm_front_evtchnl *evtchnl = dev_id; >>>> + struct xen_drm_front_info *front_info = evtchnl->front_info; >>>> + struct xendispl_resp *resp; >>>> + RING_IDX i, rp; >>>> + unsigned long flags; >>>> + >>>> + spin_lock_irqsave(&front_info->io_lock, flags); >>>> + >>>> + if (unlikely(evtchnl->state != EVTCHNL_STATE_CONNECTED)) >>>> + goto out; >>> Do you need to check the state under lock? (in other routines too). >> not really, will move out of the lock in interrupt handlers >> other places (I assume you refer to be_stream_do_io) > > I was mostly referring to evtchnl_interrupt_evt(). ah, then we are on the same page: I will move the check in interrupt handlers > -boris > > >> it is set under lock as a part of atomic operation, e.g. >> we get a new request pointer from the ring and reset completion >> So, those places still seem to be ok From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oleksandr Andrushchenko Subject: Re: [PATCH 4/9] drm/xen-front: Implement Xen event channel handling Date: Fri, 23 Feb 2018 16:49:46 +0200 Message-ID: <63c64a2f-211e-2f62-21e7-289f0cc69df0@gmail.com> References: <1519200222-20623-1-git-send-email-andr2000@gmail.com> <1519200222-20623-5-git-send-email-andr2000@gmail.com> <395cdaef-db7e-139c-bbf1-28cb33f41f58@oracle.com> <5145287f-40b0-c8e2-1b37-36d7e8cac908@gmail.com> <7d8ab151-e90d-baef-93b6-8ca1c7e42908@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; Format="flowed" Content-Transfer-Encoding: base64 Return-path: Received: from mail-lf0-x22f.google.com (mail-lf0-x22f.google.com [IPv6:2a00:1450:4010:c07::22f]) by gabe.freedesktop.org (Postfix) with ESMTPS id 203E56F166 for ; Fri, 23 Feb 2018 14:49:49 +0000 (UTC) Received: by mail-lf0-x22f.google.com with SMTP id l191so12721417lfe.1 for ; Fri, 23 Feb 2018 06:49:49 -0800 (PST) In-Reply-To: <7d8ab151-e90d-baef-93b6-8ca1c7e42908@oracle.com> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Boris Ostrovsky , xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, airlied@linux.ie, daniel.vetter@intel.com, seanpaul@chromium.org, gustavo@padovan.org, jgross@suse.com, konrad.wilk@oracle.com Cc: Oleksandr Andrushchenko List-Id: dri-devel@lists.freedesktop.org T24gMDIvMjMvMjAxOCAwNDo0NCBQTSwgQm9yaXMgT3N0cm92c2t5IHdyb3RlOgo+IE9uIDAyLzIz LzIwMTggMDI6MDAgQU0sIE9sZWtzYW5kciBBbmRydXNoY2hlbmtvIHdyb3RlOgo+PiBPbiAwMi8y My8yMDE4IDAxOjUwIEFNLCBCb3JpcyBPc3Ryb3Zza3kgd3JvdGU6Cj4+PiBPbiAwMi8yMS8yMDE4 IDAzOjAzIEFNLCBPbGVrc2FuZHIgQW5kcnVzaGNoZW5rbyB3cm90ZToKPj4+PiArCj4+Pj4gK3N0 YXRpYyBpcnFyZXR1cm5fdCBldnRjaG5sX2ludGVycnVwdF9jdHJsKGludCBpcnEsIHZvaWQgKmRl dl9pZCkKPj4+PiArewo+Pj4+ICsgICAgc3RydWN0IHhlbl9kcm1fZnJvbnRfZXZ0Y2hubCAqZXZ0 Y2hubCA9IGRldl9pZDsKPj4+PiArICAgIHN0cnVjdCB4ZW5fZHJtX2Zyb250X2luZm8gKmZyb250 X2luZm8gPSBldnRjaG5sLT5mcm9udF9pbmZvOwo+Pj4+ICsgICAgc3RydWN0IHhlbmRpc3BsX3Jl c3AgKnJlc3A7Cj4+Pj4gKyAgICBSSU5HX0lEWCBpLCBycDsKPj4+PiArICAgIHVuc2lnbmVkIGxv bmcgZmxhZ3M7Cj4+Pj4gKwo+Pj4+ICsgICAgc3Bpbl9sb2NrX2lycXNhdmUoJmZyb250X2luZm8t PmlvX2xvY2ssIGZsYWdzKTsKPj4+PiArCj4+Pj4gKyAgICBpZiAodW5saWtlbHkoZXZ0Y2hubC0+ c3RhdGUgIT0gRVZUQ0hOTF9TVEFURV9DT05ORUNURUQpKQo+Pj4+ICsgICAgICAgIGdvdG8gb3V0 Owo+Pj4gRG8geW91IG5lZWQgdG8gY2hlY2sgdGhlIHN0YXRlIHVuZGVyIGxvY2s/IChpbiBvdGhl ciByb3V0aW5lcyB0b28pLgo+PiBub3QgcmVhbGx5LCB3aWxsIG1vdmUgb3V0IG9mIHRoZSBsb2Nr IGluIGludGVycnVwdCBoYW5kbGVycwo+PiBvdGhlciBwbGFjZXMgKEkgYXNzdW1lIHlvdSByZWZl ciB0byBiZV9zdHJlYW1fZG9faW8pCj4KPiBJIHdhcyBtb3N0bHkgcmVmZXJyaW5nIHRvIGV2dGNo bmxfaW50ZXJydXB0X2V2dCgpLgphaCwgdGhlbiB3ZSBhcmUgb24gdGhlIHNhbWUgcGFnZTogSSB3 aWxsIG1vdmUgdGhlIGNoZWNrCmluIGludGVycnVwdCBoYW5kbGVycwo+IC1ib3Jpcwo+Cj4KPj4g aXQgaXMgc2V0IHVuZGVyIGxvY2sgYXMgYSBwYXJ0IG9mIGF0b21pYyBvcGVyYXRpb24sIGUuZy4K Pj4gd2UgZ2V0IGEgbmV3IHJlcXVlc3QgcG9pbnRlciBmcm9tIHRoZSByaW5nIGFuZCByZXNldCBj b21wbGV0aW9uCj4+IFNvLCB0aG9zZSBwbGFjZXMgc3RpbGwgc2VlbSB0byBiZSBvawoKX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KZHJpLWRldmVsIG1haWxp bmcgbGlzdApkcmktZGV2ZWxAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCmh0dHBzOi8vbGlzdHMuZnJl ZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vZHJpLWRldmVsCg==