From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
To: netdev@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Subject: [PATCH] ravb: fix race updating TCCR
Date: Thu, 16 Jul 2015 21:28:38 +0000 [thread overview]
Message-ID: <6587398.M5V25fvqHl@wasted.cogentembedded.com> (raw)
The TCCR.TSRQn bit may get clearead after TCCR gets read, so that TCCR write
would get skipped. We don't need to check this bit before setting.
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
---
The patch is against Dave Miller's 'net.git' repo plus the patch I sent on
Tuesday.
drivers/net/ethernet/renesas/ravb_main.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
Index: net/drivers/net/ethernet/renesas/ravb_main.c
=================================--- net.orig/drivers/net/ethernet/renesas/ravb_main.c
+++ net/drivers/net/ethernet/renesas/ravb_main.c
@@ -1275,7 +1275,6 @@ static netdev_tx_t ravb_start_xmit(struc
u32 dma_addr;
void *buffer;
u32 entry;
- u32 tccr;
spin_lock_irqsave(&priv->lock, flags);
if (priv->cur_tx[q] - priv->dirty_tx[q] >= priv->num_tx_ring[q]) {
@@ -1324,9 +1323,7 @@ static netdev_tx_t ravb_start_xmit(struc
dma_wmb();
desc->die_dt = DT_FSINGLE;
- tccr = ravb_read(ndev, TCCR);
- if (!(tccr & (TCCR_TSRQ0 << q)))
- ravb_write(ndev, tccr | (TCCR_TSRQ0 << q), TCCR);
+ ravb_write(ndev, ravb_read(ndev, TCCR) | (TCCR_TSRQ0 << q), TCCR);
priv->cur_tx[q]++;
if (priv->cur_tx[q] - priv->dirty_tx[q] >= priv->num_tx_ring[q] &&
next reply other threads:[~2015-07-16 21:28 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-16 21:28 Sergei Shtylyov [this message]
2015-07-21 3:42 ` [PATCH] ravb: fix race updating TCCR 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=6587398.M5V25fvqHl@wasted.cogentembedded.com \
--to=sergei.shtylyov@cogentembedded.com \
--cc=linux-sh@vger.kernel.org \
--cc=netdev@vger.kernel.org \
/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