diff mbox series

[v2,1/1] net: fec: ptp: avoid register access when ipg clock is disabled

Message ID 20210225205518.16781-1-heiko.thiery@gmail.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series [v2,1/1] net: fec: ptp: avoid register access when ipg clock is disabled | expand


Context Check Description
netdev/cover_letter success Link
netdev/fixes_present success Link
netdev/patch_count success Link
netdev/tree_selection success Guessed tree name to be net-next
netdev/subject_prefix warning Target tree name not specified in the subject
netdev/cc_maintainers success CCed 4 of 4 maintainers
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit fail Errors and warnings before: 0 this patch: 8
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 15 lines checked
netdev/build_allmodconfig_warn fail Errors and warnings before: 0 this patch: 8
netdev/header_inline success Link
netdev/stable success Stable not CCed

Commit Message

Heiko Thiery Feb. 25, 2021, 8:55 p.m. UTC
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

Signed-off-by: Heiko Thiery <heiko.thiery@gmail.com>
 - add mutex (thanks to Richard)

 drivers/net/ethernet/freescale/fec_ptp.c | 6 ++++++
 1 file changed, 6 insertions(+)


kernel test robot Feb. 25, 2021, 10:34 p.m. UTC | #1
Hi Heiko,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on net/master]
[also build test ERROR on net-next/master ipvs/master linus/master v5.11 next-20210225]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in

url:    https://github.com/0day-ci/linux/commits/Heiko-Thiery/net-fec-ptp-avoid-register-access-when-ipg-clock-is-disabled/20210226-050218
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git 6cf739131a15e4177e58a1b4f2bede9d5da78552
config: mips-randconfig-r013-20210225 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project a921aaf789912d981cbb2036bdc91ad7289e1523)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install mips cross compiling tool for clang build
        # apt-get install binutils-mips-linux-gnu
        # https://github.com/0day-ci/linux/commit/a7258bb15d947bb808b6209012a56ae993ec6001
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Heiko-Thiery/net-fec-ptp-avoid-register-access-when-ipg-clock-is-disabled/20210226-050218
        git checkout a7258bb15d947bb808b6209012a56ae993ec6001
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=mips 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All error/warnings (new ones prefixed by >>):

>> drivers/net/ethernet/freescale/fec_ptp.c:380:14: error: use of undeclared identifier 'fep'
   drivers/net/ethernet/freescale/fec_ptp.c:383:17: error: use of undeclared identifier 'fep'
>> drivers/net/ethernet/freescale/fec_ptp.c:384:3: warning: misleading indentation; statement is not part of the previous 'if' [-Wmisleading-indentation]
                   return -EINVAL;
   drivers/net/ethernet/freescale/fec_ptp.c:382:2: note: previous statement is here
           if (!adapter->ptp_clk_on)
   drivers/net/ethernet/freescale/fec_ptp.c:388:16: error: use of undeclared identifier 'fep'
   1 warning and 3 errors generated.

vim +/fep +380 drivers/net/ethernet/freescale/fec_ptp.c

   365	/**
   366	 * fec_ptp_gettime
   367	 * @ptp: the ptp clock structure
   368	 * @ts: timespec structure to hold the current time value
   369	 *
   370	 * read the timecounter and return the correct value on ns,
   371	 * after converting it into a struct timespec.
   372	 */
   373	static int fec_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
   374	{
   375		struct fec_enet_private *adapter =
   376		    container_of(ptp, struct fec_enet_private, ptp_caps);
   377		u64 ns;
   378		unsigned long flags;
 > 380		mutex_lock(&fep->ptp_clk_mutex);
   381		/* Check the ptp clock */
   382		if (!adapter->ptp_clk_on)
   383			mutex_unlock(&fep->ptp_clk_mutex);
 > 384			return -EINVAL;
   385		spin_lock_irqsave(&adapter->tmreg_lock, flags);
   386		ns = timecounter_read(&adapter->tc);
   387		spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
   388		mutex_unlock(&fep->ptp_clk_mutex);
   390		*ts = ns_to_timespec64(ns);
   392		return 0;
   393	}

0-DAY CI Kernel Test Service, Intel Corporation
diff mbox series


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);