From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <stable-bounces@dpdk.org>
Received: from dpdk.org (dpdk.org [92.243.14.124])
	by inbox.dpdk.org (Postfix) with ESMTP id 9F14AA04B2
	for <public@inbox.dpdk.org>; Sat, 29 Aug 2020 13:23:28 +0200 (CEST)
Received: from [92.243.14.124] (localhost [127.0.0.1])
	by dpdk.org (Postfix) with ESMTP id 637741C0B3;
	Sat, 29 Aug 2020 13:23:28 +0200 (CEST)
Received: from dispatch1-us1.ppe-hosted.com (dispatch1-us1.ppe-hosted.com
 [148.163.129.52]) by dpdk.org (Postfix) with ESMTP id 247EE1C069;
 Sat, 29 Aug 2020 13:23:25 +0200 (CEST)
Received: from mx1-us1.ppe-hosted.com (unknown [10.7.65.64])
 by dispatch1-us1.ppe-hosted.com (PPE Hosted ESMTP Server) with ESMTP id
 6703960083; Sat, 29 Aug 2020 11:23:24 +0000 (UTC)
Received: from us4-mdac16-26.ut7.mdlocal (unknown [10.7.66.46])
 by mx1-us1.ppe-hosted.com (PPE Hosted ESMTP Server) with ESMTP id 65AA12009B; 
 Sat, 29 Aug 2020 11:23:24 +0000 (UTC)
X-Virus-Scanned: Proofpoint Essentials engine
Received: from mx1-us1.ppe-hosted.com (unknown [10.7.65.175])
 by mx1-us1.ppe-hosted.com (PPE Hosted ESMTP Server) with ESMTPS id DC21F220056;
 Sat, 29 Aug 2020 11:23:23 +0000 (UTC)
Received: from webmail.solarflare.com (uk.solarflare.com [193.34.186.16])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits))
 (No client certificate requested)
 by mx1-us1.ppe-hosted.com (PPE Hosted ESMTP Server) with ESMTPS id 6375570006D;
 Sat, 29 Aug 2020 11:23:23 +0000 (UTC)
Received: from [192.168.38.17] (10.17.10.39) by ukex01.SolarFlarecom.com
 (10.17.10.4) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Sat, 29 Aug
 2020 12:23:17 +0100
To: Vipul Ashri <vipul.ashri@oracle.com>, <dev@dpdk.org>
CC: <chenbo.xia@intel.com>, <zhihong.wang@intel.com>,
 <maxime.coquelin@redhat.com>, <stable@dpdk.org>
References: <20200814092138.1692-1-vipul.ashri@oracle.com>
From: Andrew Rybchenko <arybchenko@solarflare.com>
Autocrypt: addr=arybchenko@solarflare.com; keydata=
 mQINBF2681gBEACbdTxu8eLL3UX2oAelsnK9GkeaJeUYSOHPJQpV7RL/iaIskqTwBRnhjXt7
 j9UEwGA+omnOmqQMpeQTb/F9Ma2dYE+Hw4/t/1KVjxr3ehFaASvwR4fWJfO4e2l/Rk4rG6Yi
 5r6CWU2y8su2654Fr8KFc+cMGOAgKoZTZHZsRy5lHpMlemeF+VZkv8L5sYJWPnsypgqlCG3h
 v6lbtfZs+QqYbFH6bqoZwBAl5irmxywGR7ZJr1GLUZZ1lfdazSY8r6Vz0/Ip/KVxGu2uxo81
 QCsAj0ZsQtwji9Sds/prTiPrIjx8Fc/tfbnAuVuPcnPbczwCJACzQr4q26XATL3kVuZhSBWh
 4XfO/EAUuEq5AemUG5DDTM87g7Lp4eT9gMZB6P+rJwWPNWTiV3L7Cn+fO+l9mTPnOqdzBgDe
 OaulKiNSft1o0DY4bGzOmM2ad2cZt0jfnbMPMTE9zsr6+RFa+M8Ct20o6U1MUE4vP6veErMK
 of4kZ8PdoMM+Sq1hxMPNtlcVBSP9xMmdSZPlfDYI5VWosOceEcz7XZdjBJKdwKuz70V7eac4
 ITSxgNFCTbeJ03zL2MR5s0IvD9ghISAwZ6ieCjU5UATn5+63qpD0nVNLsAdb/UpfvQcKAmvj
 0fKlxu/PMVkjBa7/4cfNogYOhWDKUO+1pMaFwvb6/XTo6uMpfQARAQABtCxBbmRyZXcgUnli
 Y2hlbmtvIDxhcnliY2hlbmtvQHNvbGFyZmxhcmUuY29tPokCVAQTAQoAPhYhBP6NPgcKRj/Y
 X0yXQahue0sAy4m+BQJduvNYAhsDBQkB4TOABQsJCAcDBRUKCQgLBRYCAwEAAh4BAheAAAoJ
 EKhue0sAy4m+t3gP/j1MNc63CEozZo1IZ2UpVPAVWTYbLdPjIRdFqhlwvZYIgGIgIBk3ezKL
 K0/oc4ZeIwL6wQ5+V24ahuXvvcxLlKxfbJ6lo2iQGC7GLGhsDG9Y2k6sW13/sTJB/XuR2yov
 k5FtIgJ+aHa1PDZnepnGGOt9ka9n/Jzrc9WKYapOIIyLRe9U26ikoVgyqsD37PVeq5tLWHHA
 NGTUKupe9G6DFWidxx0KzyMoWDTbW2AWYcEmV2eQsgRT094AZwLFN5ErfefYzsGdO8TAUU9X
 YTiQN2MvP1pBxY/r0/5UfwV4UKBcR0S3ZvzyvrPoYER2Kxdf/qurx0Mn7StiCQ/JlNZb/GWQ
 TQ7huduuZHNQKWm7ufbqvKSfbPYvfl3akj7Wl8/zXhYdLqb5mmK45HXrgYGEqPN53OnK2Ngx
 IgYKEWr05KNv09097jLT5ONgYvszflqlLIzC4dV245g7ucuf9fYmsvmM1p/gFnOJBJL18YE5
 P1fuGYNfLP+qp4WMiDqXlzaJfB4JcinyU49BXUj3Utd6f6sNBsO8YWcLbKBV9WmA324S3+wj
 f4NPRp3A5E+6OmTVMLWire2ZvnYp3YvifUj1r8lhoZ2B2vKuWwiTlHOKYBEjnOQJQnqYZEF0
 JQQ1xzVDBQKE01BPlA3vy6BGWe6I4psBVqMOB9lAev/H+xa4u6Z3uQINBF269JsBEAC2KB3W
 8JES/fh74avN7LOSdK4QA7gFIUQ4egVL81KnxquLzzilABuOhmZf3Rq6rMHSM8xmUAWa7Dkt
 YtzXStjEBI/uF0mAR3mMz1RcL2Wp+WD/15HjVpA7hPjXSEsWY0K2ymPerK4yrLcfFTHdMonY
 JfuACCC9NtOZxrWHOJoUS+RT7AWk80q/6D2iwQ47/2dBTznVG+gSeHSes9l91TB09w6f9JX/
 sT+Ud0NQfm7HJ7t2pmGI9O6Po/NLZsDogmnIpJp/WwYOZN9JK7u2FyX2UyRzR8jK42aJkRsh
 DXs16Cc2/eYGakjrdO3x9a+RoxN7EuFtYhGR1PzMXdUiB5i+FyddYXkYUyO43QE/3VPA5l1v
 TUOagzZq6aONsdNonGJkV3TIG3JmUNtM+D/+r6QKzmgoJ8w576JxEZI09I/ZFN+g7BnUmlMx
 6Z3IUOXVX/SWfGFga0YajwajHz03IBhChEbYbbqndVhmshu2GFURxrfUPYWdDXEqkh+08a5U
 Didia9jm2Opv4oE1e1TXAePyYJl/Zyps4Cv00GObAxibvMBQCUZQ+IBnNldRBOwXXRQV2xpx
 P+9iO1VYA/QXn0KqRK+SH1JGRXbJYi42YFaW1gE0EU0fiR2Wb9pK+doNEjjOhlzUGuvOEAUS
 +4m0m3dlfEvpCV9GMr7ERRpZzh9QkQARAQABiQI8BBgBCgAmFiEE/o0+BwpGP9hfTJdBqG57
 SwDLib4FAl269JsCGwwFCQlmAYAACgkQqG57SwDLib7x6g//e+eCtNnJz7qFGbjWRJYNLCe5
 gQwkhdyEGk4omr3VmjGj3z9kNFy/muh4pmHUngSAnnpwZggx14N4hhKf9y8G4Dwvsqa6b1zB
 Jq/c4t/SBDtGW4M/E331N04PaQZpcrbTfp1KqHNknk2N7yOk4CcoLVuIZmA5tPguASV8aAfz
 ZwhWAwn6vUEw9552eXEAnGFGDTCbyryNwzB5jtVQOEEDjTxcCkpcXMB45Tb1QUslRTu/sBAe
 HhPCQSUcJHR+KOq+P6yKICGAr291PZd6Qc7C3UyE+A3pY/UfdEVWj0STBWx1qvYLaHLrI4O9
 KXDgh7luLjZZafcueCaPYmNo4V2lmNb3+7S4TvqhoZS+wN+9ldRQ4gH3wmRZybN6Y/ZCqxol
 RaZpE3AqdWsGvIgAkD0FpmtZNii9s2pnrhw0K6S4t4tYgXGTossxNSJUltfFQZdXM1xkZhtv
 dBZuUEectbZWuviGvQXahOMuH2pM64mx2hpdZzPcI2beeJNHkAsGT2KcaMETgvtHUBFRlLVB
 YxsUYz3UZmi2JSua4tbcGd6iWVN90eb8CxszYtivfpz6o2nPSjNwg0NaVGSHXjAK0tdByZ9t
 SkwjC3tEPljVycRSDpbauogOiAkvjENfaPd/H26V5hY822kaclaKDAW6ZG9UKiMijcAgb9u5
 CJoOyqE8aGS5Ag0EXbr1RwEQAMXZHbafqmZiu6Kudp+Filgdkj2/XJva5Elv3fLfpXvhVt0Y
 if5Rzds3RpffoLQZk9nPwK8TbZFqNXPu7HSgg9AY7UdCM94WRFTkUCGKzbgiqGdXZ7Vyc8cy
 teGW+BcdfQycDvjfy50T3fO4kJNVp2LDNdknPaZVe8HJ80Od63+9ksB6Ni+EijMkh6Uk3ulB
 CSLnT4iFV57KgU2IsxOQVLnm+0bcsWMcCnGfphkY0yKP+aJ6MfmZkEeaDa7kf24N14ktg50m
 vOGDitcxA/+XXQXOsOIDJx1VeidxYsQ2FfsKu1G8+G6ejuaLf4rV5MI/+B/tfLbbOdikM5PF
 pxZVgTir9q13qHumMxdme7w5c7hybW412yWAe9TsrlXktFmFjRSFzAAxQhQSQxArS6db4oBk
 yeYJ59mW52i4occkimPWSm/raSgdSM+0P6zdWUlxxj+r1qiLgCYvruzLNtp5Nts5tR/HRQjE
 /ohQYaWDSVJEsc/4eGmgwzHzmvHtXeKkasn01381A1Lv3xwtpnfwERMAhxBZ8EGKEkc5gNdk
 vIPhknnGgPXqKmE1aWu8LcHiY+RHAF8gYPCDMuwyzBYnbiosKcicuIUp0Fj8XIaPao6F+WTi
 In4UOrqrYhsaCUvhVjsTBbNphGih9xbFJ8E+lkTLL8P3umtTcMPnpsB4xqcDABEBAAGJBHIE
 GAEKACYWIQT+jT4HCkY/2F9Ml0GobntLAMuJvgUCXbr1RwIbAgUJCWYBgAJACRCobntLAMuJ
 vsF0IAQZAQoAHRYhBNTYjdjWgdaEN5MrAN+9UR5r/4d3BQJduvVHAAoJEN+9UR5r/4d3EiQP
 /3lyby6v49HTU94Q2Fn2Xat6uifR7kWE5SO/1pUwYzx6v+z5K2jqPgqUYmuNoejcGl0CTNhg
 LbsxzUmAuf1OTAdE+ZYvOAjjKQhY4haxHc4enby/ltnHfWJYWJZ9UN5SsIQLvITvYu6rqthO
 CYjpXJhwkj3ODmC9H1TrvjrBGc6i7CTnR8RCjMEwCs2LI2frHa4R6imViEr9ScMfUnzdABMQ
 B0T5MOg8NX92/FRjTldU2KovG0ML9mSveSvVHAoEBLy4UIs5nEDdNiO1opJgKb5CXvWQugub
 7AR52phNdKVdEB0S4tigJT4NalyTaPiUhFEm+CzZpMQDJ5E+/OowaPRfN4HeJX+c8sB+vUAZ
 mkAaG75N+IEk5JKFK9Z+bBYgPgaBDFZYdWDB/TMH0ANt+KI5uYg0i12TB4M8pwKG1DEPUmWc
 F2YpvB3jnbwzsOpSFiJOOlSs6nOB0Sb5GRtPOO3h6XGj+6mzQd6tcL63c9TrrUkjq7LDkxCz
 SJ2hTYRC8WNX8Uw9skWo5728JNrXdazEYCenUWmYiKLNKLslXCFodUCRDh/sUiyqRwS7PHEA
 LYC/UIWLMomI0Yvju3KA5v3RQVXhL+Gx2CzSj3GDz9xxGhJB2LfRfjzPbTR/Z27UpjCkd8z0
 Ro3Ypmi1FLQwnRgoOKDbetTAIhugEShaLTITzJAP/iRDJCQsrZah5tE8oIl81qKEmBJEGcdt
 HYikbpQe7ydcXhqTj7+IECa3O7azI5OhCxUH2jNyonJ/phUslHH2G1TTBZK8y4Hrx5RpuRNS
 esn3P9uKu9DHqBAL7DMsCPwb2p1VNnapD72DBmRhzS/e6zS2R4+r9yNv03Hv7VCxKkmtE63H
 qpS//qpjfrtsIcHAjnKDaDtL1LYCtHoweI+DOpKKULSAYp/JE6F8LNibPQ0/P3S5ZIJNC4QZ
 uESjFOalJwFIqGQdkQB7ltRNJENLrHc+2jKGOuyFHm/Sbvp5EMGdaeQ0+u8CY0P+y6oXenwx
 7WrJz/GvbNoFhJoJ6RzxCMQrFgxrssVZ7w5HcUj94lbnJ6osdYE/WpSd50B6jet6LKh5revg
 u9XI9CoqsPQ1V4wKYYdllPuogCye7KNYNKuiiuSNpaF4gHq1ZWGArwZtWHjgc2v3LegOpRQF
 SwOskMKmWsUyHIRMG1p8RpkBQTqY2rGSeUqPSvaqjT0nq+SUEM6qxEXD/2Wqri/X6bamuPDb
 S0PkBvFD2+0zr5Bc2YkMGPBYPNGZiTp3UjmZlLfn3TiBKIC92jherY563CULjSsiBEJCOSvv
 4VPLn5aAcfbCXJnE3IGCp/hPl50iQqu7BPOYBbWXeb9ptDjGCAThNxSz0WAXkmcjAFE8gdE6 Znk9
Message-ID: <7a2d66d6-3961-5251-36d2-c702fe80379f@solarflare.com>
Date: Sat, 29 Aug 2020 14:22:54 +0300
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.11.0
MIME-Version: 1.0
In-Reply-To: <20200814092138.1692-1-vipul.ashri@oracle.com>
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 8bit
Content-Language: en-US
X-Originating-IP: [10.17.10.39]
X-ClientProxiedBy: ocex03.SolarFlarecom.com (10.20.40.36) To
 ukex01.SolarFlarecom.com (10.17.10.4)
X-TM-AS-Product-Ver: SMEX-12.5.0.1300-8.6.1012-25632.006
X-TM-AS-Result: No-3.665300-8.000000-10
X-TMASE-MatchedRID: QW5G6BKkLTrmLzc6AOD8DfHkpkyUphL9PSgberZ8hXIep400rdpOCylA
 /rS07QvhZAJRHrn2lvF6MBOevfwGOFtv7lVTl559Gi6hW8XaLRkB4JHtiamkLB3RY4pGTCyHEG3
 UzQEO6wpJRQdHihGwKpscC5DV1Se5YlldA0POS1JtawJSSsDgSQZyESFXAljfJHDdhWbn1ZL4HI
 V+hS/jtcZTkhkQFUsTs/uAbQfk04oBI9QFQ7SSeAGdJZ3Knh6hzPMyzZ3J7JUjRiu1AuxJTN60m
 7hcW9khP+TN275v+89ftuJwrFEhTbew1twePJJB3QfwsVk0UbsIoUKaF27lxZUC/k0gvy31iH+B
 jKqL2DZzikYmYghvcmv2pCv7GLPqFCzVDIGCo+v7R3cMsB/kqO72L/4BQw03A8tIE07yajnpBFK
 2p7jqi6KAQfLsnhLrKWSt4DmvbhpicKLmK2TeKmsPn5C6nWpTnqg/VrSZEiM=
X-TM-AS-User-Approved-Sender: Yes
X-TM-AS-User-Blocked-Sender: No
X-TMASE-Result: 10--3.665300-8.000000
X-TMASE-Version: SMEX-12.5.0.1300-8.6.1012-25632.006
X-MDID: 1598700204-nrjgVtbNETSk
Subject: Re: [dpdk-stable] [dpdk-dev] [PATCH] net/virtio: fix wrong variable
 assignment in helper macro
X-BeenThere: stable@dpdk.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: patches for DPDK stable branches <stable.dpdk.org>
List-Unsubscribe: <https://mails.dpdk.org/options/stable>,
 <mailto:stable-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://mails.dpdk.org/archives/stable/>
List-Post: <mailto:stable@dpdk.org>
List-Help: <mailto:stable-request@dpdk.org?subject=help>
List-Subscribe: <https://mails.dpdk.org/listinfo/stable>,
 <mailto:stable-request@dpdk.org?subject=subscribe>
Errors-To: stable-bounces@dpdk.org
Sender: "stable" <stable-bounces@dpdk.org>

On 8/14/20 12:21 PM, Vipul Ashri wrote:
> Inside Macro ASSIGN_UNLESS_EQUAL(var, val), assignment to var is always
> failing as assignment done using var_ having local scope only.
> This leads to TX packets not going out and found broken due to cleanup
> malfunctioning. This patch fixes the wrong variable assignment.
>
> Fixes: 57f90f894588 ("net/virtio: reuse packed ring functions")
> Cc: stable@dpdk.org
>
> Signed-off-by: Vipul Ashri <vipul.ashri@oracle.com>
> ---
>  drivers/net/virtio/virtqueue.h | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/virtio/virtqueue.h b/drivers/net/virtio/virtqueue.h
> index 105a9c00c..20c95471e 100644
> --- a/drivers/net/virtio/virtqueue.h
> +++ b/drivers/net/virtio/virtqueue.h
> @@ -607,10 +607,8 @@ virtqueue_notify(struct virtqueue *vq)
>  
>  /* avoid write operation when necessary, to lessen cache issues */
>  #define ASSIGN_UNLESS_EQUAL(var, val) do {	\
> -	typeof(var) var_ = (var);		\
> -	typeof(val) val_ = (val);		\
> -	if ((var_) != (val_))			\
> -		(var_) = (val_);		\
> +	if ((var) != (val))			\
> +		(var) = (val);			\

Good catch. As I understand the old code tries to avoid
processing of var and val expressions twice. It looks it
could be kept for val at least. Just keep if condition as in
old code and fix the last line above:
    (var) = val_;
Since var_ and val_are local variables there is no necessity
to enclose it in parenthesis (but does not harm if done).
var_ may be really removed since since resulting code will
use it only once.