From: Vincent Chen <vincentc@andestech.com>
To: <davem@davemloft.net>, <gregkh@linuxfoundation.org>,
<rdunlap@infradead.org>, <yuehaibing@huawei.com>
Cc: <vincentc@andestech.com>, <netdev@vger.kernel.org>,
<linux-kernel@vger.kernel.org>
Subject: [PATCH v2] net: faraday: ftmac100: remove netif_running(netdev) check before disabling interrupts
Date: Wed, 21 Nov 2018 09:38:11 +0800 [thread overview]
Message-ID: <1542764291-11208-1-git-send-email-vincentc@andestech.com> (raw)
In the original ftmac100_interrupt(), the interrupts are only disabled when
the condition "netif_running(netdev)" is true. However, this condition
causes kerenl hang in the following case. When the user requests to
disable the network device, kernel will clear the bit __LINK_STATE_START
from the dev->state and then call the driver's ndo_stop function. Network
device interrupts are not blocked during this process. If an interrupt
occurs between clearing __LINK_STATE_START and stopping network device,
kernel cannot disable the interrupts due to the condition
"netif_running(netdev)" in the ISR. Hence, kernel will hang due to the
continuous interruption of the network device.
In order to solve the above problem, the interrupts of the network device
should always be disabled in the ISR without being restricted by the
condition "netif_running(netdev)".
[V2]
Remove unnecessary curly braces.
Signed-off-by: Vincent Chen <vincentc@andestech.com>
---
drivers/net/ethernet/faraday/ftmac100.c | 7 +++----
1 files changed, 3 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/faraday/ftmac100.c b/drivers/net/ethernet/faraday/ftmac100.c
index 21d7660..17a3625 100644
--- a/drivers/net/ethernet/faraday/ftmac100.c
+++ b/drivers/net/ethernet/faraday/ftmac100.c
@@ -875,11 +875,10 @@ static irqreturn_t ftmac100_interrupt(int irq, void *dev_id)
struct net_device *netdev = dev_id;
struct ftmac100 *priv = netdev_priv(netdev);
- if (likely(netif_running(netdev))) {
- /* Disable interrupts for polling */
- ftmac100_disable_all_int(priv);
+ /* Disable interrupts for polling */
+ ftmac100_disable_all_int(priv);
+ if (likely(netif_running(netdev)))
napi_schedule(&priv->napi);
- }
return IRQ_HANDLED;
}
--
1.7.1
next reply other threads:[~2018-11-21 1:38 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-21 1:38 Vincent Chen [this message]
2018-11-22 0:58 ` [PATCH v2] net: faraday: ftmac100: remove netif_running(netdev) check before disabling interrupts David Miller
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=1542764291-11208-1-git-send-email-vincentc@andestech.com \
--to=vincentc@andestech.com \
--cc=davem@davemloft.net \
--cc=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=rdunlap@infradead.org \
--cc=yuehaibing@huawei.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).