[PATCH net] net: stmmac: report phc_index as -1 when no PTP clock is registered

[Lorenzo Bianconi]

On Sep 14, Gal Pressman wrote:
> On 13/09/2026 0:16, Lorenzo Bianconi wrote:
> > When hardware timestamping is supported but no PTP clock has been
> > registered yet (e.g. while the interface is down), stmmac_get_ts_info()
> > currently reports phc_index as 0. Zero is a valid PHC index and would
> > make userspace resolve the wrong clock; the absence of a clock should
> > be reported as -1, matching ethtool_init_tsinfo() and
> > ethtool_op_get_ts_info().
> > 
> > Report -1 when no PTP clock is available.
> > 
> > Fixes: 9364fa7fcf12 ("net: stmmac: Remove setting of RX software timestamp")
> > Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi at oss.qualcomm.com>
> In all other drivers I just removed the assignment, why not do the same
> here?

Ack, I agree. Since we run ethtool_init_tsinfo() before running the
get_ts_info() callback, we can drop phc_index initialization to -1.
I will fix it in v2.

Regards,
Lorenzo
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