6.6-stable review patch. If anyone has any objections, please let me know.
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From: Vladimir Oltean vladimir.oltean@nxp.com
[ Upstream commit aa112cbc5f0ac6f3b44d829005bf34005d9fe9bb ]
There is a bug in ptp_clock_adjtime() which makes it refuse the operation even if we just want to read the current clock dialed frequency, not modify anything (tx->modes == 0). That should be possible even if the clock is free-running. For context, the kernel UAPI is the same for getting and setting the frequency of a POSIX clock.
For example, ptp4l errors out at clock_create() -> clockadj_get_freq() -> clock_adjtime() time, when it should logically only have failed on actual adjustments to the clock, aka if the clock was configured as slave. But in master mode it should work.
This was discovered when examining the issue described in the previous commit, where ptp_clock_freerun() returned true despite n_vclocks being zero.
Fixes: 73f37068d540 ("ptp: support ptp physical/virtual clocks conversion") Signed-off-by: Vladimir Oltean vladimir.oltean@nxp.com Link: https://patch.msgid.link/20250613174749.406826-3-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/ptp/ptp_clock.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c index 6b7e8b7ebcef5..b7fc260ed43bc 100644 --- a/drivers/ptp/ptp_clock.c +++ b/drivers/ptp/ptp_clock.c @@ -104,7 +104,8 @@ static int ptp_clock_adjtime(struct posix_clock *pc, struct __kernel_timex *tx) struct ptp_clock_info *ops; int err = -EOPNOTSUPP;
- if (ptp_clock_freerun(ptp)) { + if (tx->modes & (ADJ_SETOFFSET | ADJ_FREQUENCY | ADJ_OFFSET) && + ptp_clock_freerun(ptp)) { pr_err("ptp: physical clock is free running\n"); return -EBUSY; }