Re: [PATCH net-next v5 05/13] net: pcs: add Renesas MII converter driver

[Clément Léger]

Le Thu, 19 May 2022 17:25:10 +0100,
"Russell King (Oracle)" <linux@xxxxxxxxxxxxxxx> a écrit :

> Hi,
> 
> On Thu, May 19, 2022 at 05:30:59PM +0200, Clément Léger wrote:
> > Add a PCS driver for the MII converter that is present on the Renesas
> > RZ/N1 SoC. This MII converter is reponsible for converting MII to
> > RMII/RGMII or act as a MII pass-trough. Exposing it as a PCS allows to
> > reuse it in both the switch driver and the stmmac driver. Currently,
> > this driver only allows the PCS to be used by the dual Cortex-A7
> > subsystem since the register locking system is not used.
> > 
> > Signed-off-by: Clément Léger <clement.leger@xxxxxxxxxxx>  
> 
> Looks much better now, thanks. Only one thing I've spotted is:
> 
> > +static int miic_validate(struct phylink_pcs *pcs, unsigned long *supported,
> > +			 const struct phylink_link_state *state)
> > +{
> > +	if (state->interface == PHY_INTERFACE_MODE_RGMII ||
> > +	    state->interface == PHY_INTERFACE_MODE_RGMII_ID ||
> > +	    state->interface == PHY_INTERFACE_MODE_RGMII_TXID ||
> > +	    state->interface == PHY_INTERFACE_MODE_RGMII_RXID ||  
> 
> The above could use:
> 
> 	if (phy_interface_mode_is_rgmii(state->interface) ||

Thanks, I did found the one to set the bit for phylink part but not
this one.

> 
> Also, as a request to unbind this driver would be disasterous to users,
> I think you should set ".suppress_bind_attrs = true" to prevent the
> sysfs bind/unbind facility being available. This doesn't completely
> solve the problem.

Acked. What should I do to make it more robust ? Should I use a
refcount per pdev and check that in the remove() callback to avoid
removing the pdev if used ?

Thanks,

-- 
Clément Léger,
Embedded Linux and Kernel engineer at Bootlin
https://bootlin.com