From: richardcochran@gmail.com (Richard Cochran)
To: linux-arm-kernel@lists.infradead.org
Subject: [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: 14+ 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 14:28 ` [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
[not found] ` <1496413661-21452-1-git-send-email-rafalo@cadence.com>
2017-06-06 18:39 ` [PATCH v2 3/4] net: macb: macb.c changed to macb_main.c Richard Cochran
2017-06-06 19:00 ` David Miller
2017-06-06 20:22 ` Richard Cochran
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