From: Heiko Thiery <heiko.thiery@gmail.com>
To: netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Fugang Duan <fugang.duan@nxp.com>,
"David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Richard Cochran <richardcochran@gmail.com>,
Heiko Thiery <heiko.thiery@gmail.com>
Subject: [PATCH v2 1/1] net: fec: ptp: avoid register access when ipg clock is disabled
Date: Thu, 25 Feb 2021 21:55:19 +0100 [thread overview]
Message-ID: <20210225205518.16781-1-heiko.thiery@gmail.com> (raw)
When accessing the timecounter register on an i.MX8MQ the kernel hangs.
This is only the case when the interface is down. This can be reproduced
by reading with 'phc_ctrl eth0 get'.
Like described in the change in 91c0d987a9788dcc5fe26baafd73bf9242b68900
the igp clock is disabled when the interface is down and leads to a
system hang.
So we check if the ptp clock status before reading the timecounter
register.
Signed-off-by: Heiko Thiery <heiko.thiery@gmail.com>
---
v2:
- add mutex (thanks to Richard)
drivers/net/ethernet/freescale/fec_ptp.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/net/ethernet/freescale/fec_ptp.c b/drivers/net/ethernet/freescale/fec_ptp.c
index 2e344aada4c6..22f5e800c2d7 100644
--- a/drivers/net/ethernet/freescale/fec_ptp.c
+++ b/drivers/net/ethernet/freescale/fec_ptp.c
@@ -377,9 +377,15 @@ static int fec_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
u64 ns;
unsigned long flags;
+ mutex_lock(&fep->ptp_clk_mutex);
+ /* Check the ptp clock */
+ if (!adapter->ptp_clk_on)
+ mutex_unlock(&fep->ptp_clk_mutex);
+ return -EINVAL;
spin_lock_irqsave(&adapter->tmreg_lock, flags);
ns = timecounter_read(&adapter->tc);
spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
+ mutex_unlock(&fep->ptp_clk_mutex);
*ts = ns_to_timespec64(ns);
--
2.30.0
next reply other threads:[~2021-02-25 21:08 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-25 20:55 Heiko Thiery [this message]
2021-02-25 22:34 ` [PATCH v2 1/1] net: fec: ptp: avoid register access when ipg clock is disabled kernel test robot
2021-02-25 21:15 Heiko Thiery
2021-02-26 7:22 ` Heiko Thiery
2021-02-26 15:23 ` Richard Cochran
2021-02-26 23:44 ` Jakub Kicinski
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