Re: [PATCH 3/4 net] qca_spi: Fix ethtool -G iface tx behavior

[Stefan Wahren]

Hi Paolo,

Am 23.11.23 um 12:51 schrieb Paolo Abeni:
> On Tue, 2023-11-21 at 17:30 +0100, Stefan Wahren wrote:
> > After calling ethtool -g it was not possible to adjust the TX ring size
> > again.
> Could you please report the exact command sequence that will fail?
ethtool -g eth1
ethtool -G eth1 tx 8
> > The reason for this is that the readonly setting rx_pending get
> > initialized and after that the range check in qcaspi_set_ringparam()
> > fails regardless of the provided parameter. Since there is no adjustable
> > RX ring at all, drop it from qcaspi_get_ringparam().
> > Fixes: 291ab06ecf67 ("net: qualcomm: new Ethernet over SPI driver for QCA7000")
> > Signed-off-by: Stefan Wahren <wahrenst@xxxxxxx>
> > ---
> >   drivers/net/ethernet/qualcomm/qca_debug.c | 2 --
> >   1 file changed, 2 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/qualcomm/qca_debug.c b/drivers/net/ethernet/qualcomm/qca_debug.c
> > index 6f2fa2a42770..613eb688cba2 100644
> > --- a/drivers/net/ethernet/qualcomm/qca_debug.c
> > +++ b/drivers/net/ethernet/qualcomm/qca_debug.c
> > @@ -252,9 +252,7 @@ qcaspi_get_ringparam(struct net_device *dev, struct ethtool_ringparam *ring,
> >   {
> >   	struct qcaspi *qca = netdev_priv(dev);
> >
> > -	ring->rx_max_pending = 4;
> >   	ring->tx_max_pending = TX_RING_MAX_LEN;
> > -	ring->rx_pending = 4;
> >   	ring->tx_pending = qca->txr.count;
> >   }
> I think it's preferable update qcaspi_set_ringparam() to complete
> successfully when the provided arguments don't change the rx_pending
> default (4)

Sorry, i didn't get. The whole point is that there is no RX ring at all,
just a TX ring. During the time of writing this driver, i was under the
assumption that the driver needs to provide a rx_pending in
qcaspi_get_ringparam even this is no RX ring. The number 4 represent the
maximum of 4 packets which can be received at once. But it's not a ring.

Best regards

> Cheers,
>
> Paolo