[PATCH net] net: ethernet: ti: icssg: guard PA stat lookups

[Philippe Schenker]

Hi Simon

Thanks for the review and I'll send a v2 with that blank line removed.
Saw it right after sending the patch.

Philippe

On Thu, 2026-06-18 at 10:10 +0100, Simon Horman wrote:
> On Tue, Jun 16, 2026 at 04:35:34PM +0200, Philippe Schenker wrote:
> > From: Philippe Schenker <philippe.schenker at impulsing.ch>
> > 
> > icssg_ndo_get_stats64() unconditionally calls
> > emac_get_stat_by_name()
> > with FW PA stat names regardless of whether the PA stats block is
> > present on the hardware.  emac_get_stat_by_name() already guards
> > the
> > PA stats lookup with `if (emac->prueth->pa_stats)`; when that
> > pointer
> > is NULL the lookup falls through to netdev_err() and returns -
> > EINVAL.
> > Because ndo_get_stats64 is polled regularly by the networking stack
> > this produces thousands of log entries of the form:
> > 
> >   icssg-prueth icssg1-eth end0: Invalid stats FW_RX_ERROR
> > 
> > A secondary consequence is that the int(-EINVAL) return value is
> > implicitly widened to a near-ULLONG_MAX unsigned value when
> > accumulated
> > into the __u64 fields of rtnl_link_stats64, silently corrupting the
> > rx_errors, rx_dropped and tx_dropped counters reported by `ip -s
> > link`.
> > 
> > Every other PA-aware code path in the driver is already guarded
> > with
> > the same `if (emac->prueth->pa_stats)` check.  Apply the same guard
> > here.
> > 
> > Fixes: 0d15a26b247d ("net: ti: icssg-prueth: Add ICSSG FW Stats")
> 
> nit: no blank line between tags
> 
> > 
> > Signed-off-by: Philippe Schenker <philippe.schenker at impulsing.ch>
> > 
> > Cc: danishanwar at ti.com
> > Cc: rogerq at kernel.org
> > Cc: linux-arm-kernel at lists.infradead.org
> > Cc: stable at vger.kernel.org
> 
> Reviewed-by: Simon Horman <horms at kernel.org>
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