DPDK patches and discussions
 help / color / mirror / Atom feed
From: Vipul Ashri <vipul.ashri@oracle.com>
To: dev@dpdk.org
Cc: chenbo.xia@intel.com, vipul.ashri@oracle.com,
	zhihong.wang@intel.com, maxime.coquelin@redhat.com,
	arybchenko@solarflare.com, makarov@kraftway.ru, stable@dpdk.org
Subject: [dpdk-dev] [PATCH v4] net/virtio: fix wrong variable assignment in helper macro
Date: Wed, 16 Sep 2020 11:27:24 +0530	[thread overview]
Message-ID: <20200916055725.1473-1-vipul.ashri@oracle.com> (raw)
In-Reply-To: <20200813072837.1468-1-vipul.ashri@oracle.com>

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 | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/net/virtio/virtqueue.h b/drivers/net/virtio/virtqueue.h
index 105a9c00c..7f8a3976f 100644
--- a/drivers/net/virtio/virtqueue.h
+++ b/drivers/net/virtio/virtqueue.h
@@ -607,10 +607,11 @@ 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_);		\
+	typeof(var) *const var_ = &(var);	\
+	typeof(val)  const val_ = (val);	\
+	if (*var_ != val_)			\
+		*var_ = val_;			\
+
 } while (0)
 
 #define virtqueue_clear_net_hdr(hdr) do {		\
-- 
2.28.0.windows.1


  parent reply	other threads:[~2020-09-16  6:01 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-07 12:57 [dpdk-dev] [PATCH] Virtio TX: reverting a small change causing Virtio standard TX broken Vipul Ashri
2020-08-09 13:28 ` Vipul Ashri
2020-08-10  4:10 ` Xia, Chenbo
2020-08-10 19:59 ` [dpdk-dev] [PATCH v2] net/virtio: fix 57f90f8("net/virtio: reuse packed ring functions") Vipul Ashri
2020-08-11  1:39   ` Xia, Chenbo
2020-08-12  9:23   ` [dpdk-dev] [PATCH v2] Fixes: 57f90f894588("net/virtio: " Vipul Ashri
2020-08-12 12:00     ` Xia, Chenbo
2020-08-13  7:23       ` [dpdk-dev] FW: " Vipul Ashri
2020-08-13  7:27         ` chupenghong
2020-08-13  7:25     ` [dpdk-dev] [PATCH v2] net/virtio: fix wrong variable assignment in helper macro Vipul Ashri
2020-08-13  7:28     ` [dpdk-dev] [PATCH v3] " Vipul Ashri
2020-08-13  7:35       ` Xia, Chenbo
2020-08-19  1:25       ` Xia, Chenbo
2020-09-16  5:57       ` Vipul Ashri [this message]
2020-09-17 15:54         ` [dpdk-dev] [PATCH v4] " Andrew Rybchenko
2020-09-18  9:55       ` [dpdk-dev] [PATCH v5] " Vipul Ashri
2020-09-18 12:22         ` Maxime Coquelin
2020-09-18 12:30         ` Maxime Coquelin
2020-08-13 16:22 ` [dpdk-dev] [PATCH v3] " Vipul Ashri
2020-08-14  1:25   ` Xia, Chenbo
2020-08-14  5:23     ` Vipul Ashri
2020-08-18 18:45       ` Ferruh Yigit
2020-08-18 20:46         ` Vipul Ashri

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200916055725.1473-1-vipul.ashri@oracle.com \
    --to=vipul.ashri@oracle.com \
    --cc=arybchenko@solarflare.com \
    --cc=chenbo.xia@intel.com \
    --cc=dev@dpdk.org \
    --cc=makarov@kraftway.ru \
    --cc=maxime.coquelin@redhat.com \
    --cc=stable@dpdk.org \
    --cc=zhihong.wang@intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).