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 <[email protected]>
---
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
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
https://git-scm.com/docs/git-format-patch]
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 <[email protected]>
All error/warnings (new ones prefixed by >>):
>> drivers/net/ethernet/freescale/fec_ptp.c:380:14: error: use of undeclared identifier 'fep'
mutex_lock(&fep->ptp_clk_mutex);
^
drivers/net/ethernet/freescale/fec_ptp.c:383:17: error: use of undeclared identifier 'fep'
mutex_unlock(&fep->ptp_clk_mutex);
^
>> 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'
mutex_unlock(&fep->ptp_clk_mutex);
^
1 warning and 3 errors generated.
vim +/fep +380 drivers/net/ethernet/freescale/fec_ptp.c
364
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;
379
> 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);
389
390 *ts = ns_to_timespec64(ns);
391
392 return 0;
393 }
394
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/[email protected]