From: Richard Cochran <richardcochran@gmail.com>
To: Rafal Ozieblo <rafalo@cadence.com>
Cc: David Miller <davem@davemloft.net>,
"nicolas.ferre@atmel.com" <nicolas.ferre@atmel.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"harini.katakam@xilinx.com" <harini.katakam@xilinx.com>,
"andrei.pistirica@microchip.com" <andrei.pistirica@microchip.com>
Subject: Re: [PATCH v2 4/4] net: macb: Add hardware PTP support
Date: Wed, 7 Jun 2017 15:28:17 +0200 [thread overview]
Message-ID: <20170607132817.GA28329@localhost.localdomain> (raw)
In-Reply-To: <BN3PR07MB2516A47C2CFEB58BCFFB2C46C9C80@BN3PR07MB2516.namprd07.prod.outlook.com>
On Wed, Jun 07, 2017 at 11:13:36AM +0000, Rafal Ozieblo wrote:
> Please look at following call-stack:
>
> 1. macb_interrupt() // spin_lock(&bp->lock) is taken
> 2. macb_tx_interrupt()
> 3. macb_handle_txtstamp()
> 4. skb_tstamp_tx()
> 5. __skb_tstamp_tx()
> 6. skb_may_tx_timestamp()
> 7. read_lock_bh() // second lock is taken
Well, you can always drop the lock, or postpone the call to
skb_tstamp_tx() until after the spin lock is released...
> I know that those are different locks and different types. But this could lead
> to deadlocks. This is the reason of warning I could see.
Can you please post the lockdep splat?
Thanks,
Richard
next prev parent reply other threads:[~2017-06-07 13:28 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-02 14:23 [PATCH v2 0/4] PTP support for macb driver Rafal Ozieblo
2017-06-02 14:26 ` [PATCH v2 1/4] net: macb: Add support for PTP timestamps in DMA descriptors Rafal Ozieblo
2017-06-02 14:27 ` [PATCH v2 2/4] net: macb: Add tsu_clk to device tree Rafal Ozieblo
2017-06-02 14:27 ` [PATCH v2 3/4] net: macb: macb.c changed to macb_main.c Rafal Ozieblo
2017-06-06 18:39 ` Richard Cochran
2017-06-06 19:00 ` David Miller
2017-06-06 20:22 ` Richard Cochran
2017-06-02 14:28 ` [PATCH v2 4/4] net: macb: Add hardware PTP support Rafal Ozieblo
2017-06-04 20:55 ` Richard Cochran
2017-06-06 8:54 ` Rafal Ozieblo
2017-06-06 18:36 ` Richard Cochran
2017-06-06 18:33 ` Richard Cochran
2017-06-07 11:13 ` Rafal Ozieblo
2017-06-07 13:28 ` Richard Cochran [this message]
2017-06-08 12:48 ` Rafal Ozieblo
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=20170607132817.GA28329@localhost.localdomain \
--to=richardcochran@gmail.com \
--cc=andrei.pistirica@microchip.com \
--cc=davem@davemloft.net \
--cc=devicetree@vger.kernel.org \
--cc=harini.katakam@xilinx.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=nicolas.ferre@atmel.com \
--cc=rafalo@cadence.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).