Subject: Re: [RFC PATCH 2/9] net: dsa: Add DSA driver for Hirschmann Hellcreek switches

From: Andrew Lunn <[email-masked]>
Date: Thu, 18 Jun 2020 17:22:47 +0200

> +static void __hellcreek_select_port(struct hellcreek *hellcreek, int port)

Hi Kurt

In general, please can you drop all these __ prefixes. They are useful
when you have for example hellcreek_select_port() takes a lock and
then calls _hellcreek_select_port(), but here, there is no need for
them.

> +static int hellcreek_detect(struct hellcreek *hellcreek)
> +{
> +	u8 tgd_maj, tgd_min;
> +	u16 id, rel_low, rel_high, date_low, date_high, tgd_ver;
> +	u32 rel, date;

Reverse Christmas tree please. Here and everywhere else.

> +
> +	id	  = hellcreek_read(hellcreek, HR_MODID_C);
> +	rel_low	  = hellcreek_read(hellcreek, HR_REL_L_C);
> +	rel_high  = hellcreek_read(hellcreek, HR_REL_H_C);
> +	date_low  = hellcreek_read(hellcreek, HR_BLD_L_C);
> +	date_high = hellcreek_read(hellcreek, HR_BLD_H_C);
> +	tgd_ver   = hellcreek_read(hellcreek, TR_TGDVER);
> +
> +	if (id != HELLCREEK_MODULE_ID)
> +		return -ENODEV;
> +
> +	rel	= rel_low | (rel_high << 16);
> +	date	= date_low | (date_high << 16);
> +	tgd_maj = (tgd_ver & TR_TGDVER_REV_MAJ_MASK) >> TR_TGDVER_REV_MAJ_SHIFT;
> +	tgd_min = (tgd_ver & TR_TGDVER_REV_MIN_MASK) >> TR_TGDVER_REV_MIN_SHIFT;
> +
> +	dev_info(hellcreek->dev, "Module ID=%02x Release=%04x Date=%04x TGD Version=%02x.%02x\n",
> +		 id, rel, date, tgd_maj, tgd_min);
> +
> +	return 0;
> +}

> +static int hellcreek_port_enable(struct dsa_switch *ds, int port,
> +				 struct phy_device *phy)
> +{
> +	struct hellcreek *hellcreek = ds->priv;
> +	struct hellcreek_port *hellcreek_port = &hellcreek->ports[port];
> +	unsigned long flags;
> +	u16 val;
> +
> +	if (port >= NUM_PORTS)
> +		return -EINVAL;
> +
> +	dev_info(hellcreek->dev, "Enable port %d\n", port);

dev_dbg().

+
> +	spin_lock_irqsave(&hellcreek->reg_lock, flags);

I've not seen any interrupt handling code in the driver, and there is
no mention of an interrupt in the DT binding. Do you really need
_irqsave spin locks?

> +
> +	__hellcreek_select_port(hellcreek, port);
> +	val = hellcreek_port->ptcfg;
> +	val |= HR_PTCFG_ADMIN_EN;
> +	hellcreek_write(hellcreek, val, HR_PTCFG);
> +	hellcreek_port->ptcfg = val;
> +
> +	spin_unlock_irqrestore(&hellcreek->reg_lock, flags);
> +
> +	return 0;
> +}
> +
> +static void hellcreek_port_disable(struct dsa_switch *ds, int port)
> +{
> +	struct hellcreek *hellcreek = ds->priv;
> +	struct hellcreek_port *hellcreek_port = &hellcreek->ports[port];
> +	unsigned long flags;
> +	u16 val;
> +
> +	if (port >= NUM_PORTS)
> +		return;

I don't think this test is actually needed, here or in any of the
other callbacks. If it does happen, it means we have a core bug we
should fix.

> +
> +	dev_info(hellcreek->dev, "Disable port %d\n", port);

dev_dbg()

> +	spin_lock_irqsave(&hellcreek->reg_lock, flags);
> +
> +	__hellcreek_select_port(hellcreek, port);
> +	val = hellcreek_port->ptcfg;
> +	val &= ~HR_PTCFG_ADMIN_EN;
> +	hellcreek_write(hellcreek, val, HR_PTCFG);
> +	hellcreek_port->ptcfg = val;
> +
> +	spin_unlock_irqrestore(&hellcreek->reg_lock, flags);
> +}
> +

> +static void hellcreek_get_ethtool_stats(struct dsa_switch *ds, int port,
> +					uint64_t *data)
> +{
> +	struct hellcreek *hellcreek = ds->priv;
> +	struct hellcreek_port *hellcreek_port = &hellcreek->ports[port];
> +	unsigned long flags;
> +	int i;
> +
> +	if (port >= NUM_PORTS)
> +		return;
> +
> +	spin_lock_irqsave(&hellcreek->reg_lock, flags);
> +	for (i = 0; i < ARRAY_SIZE(hellcreek_counter); ++i) {
> +		const struct hellcreek_counter *counter = &hellcreek_counter[i];
> +		u8 offset = counter->offset + port * 64;
> +		u16 high, low;
> +		u64 value = 0;
> +
> +		__hellcreek_select_counter(hellcreek, offset);
> +
> +		high  = hellcreek_read(hellcreek, HR_CRDH);
> +		low   = hellcreek_read(hellcreek, HR_CRDL);
> +		value = (high << 16) | low;

Is there some sort of snapshot happening here? Or do you need to read
high again, to make sure it has not incremented when low was being
read?

> +
> +		hellcreek_port->counter_values[i] += value;
> +		data[i] = hellcreek_port->counter_values[i];
> +	}
> +	spin_unlock_irqrestore(&hellcreek->reg_lock, flags);
> +}
> +
> +static int hellcreek_vlan_prepare(struct dsa_switch *ds, int port,
> +				  const struct switchdev_obj_port_vlan *vlan)
> +{
> +	struct hellcreek *hellcreek = ds->priv;
> +
> +	/* Nothing todo */
> +	dev_info(hellcreek->dev, "VLAN prepare for port %d\n", port);

dev_dbg()

> +
> +	return 0;
> +}
> +

> +static void hellcreek_vlan_add(struct dsa_switch *ds, int port,
> +			       const struct switchdev_obj_port_vlan *vlan)
> +{
> +	struct hellcreek *hellcreek = ds->priv;
> +	bool untagged = vlan->flags & BRIDGE_VLAN_INFO_UNTAGGED;
> +	bool pvid = vlan->flags & BRIDGE_VLAN_INFO_PVID;
> +	unsigned long flags;
> +	u16 vid;
> +
> +	if (port >= NUM_PORTS || vlan->vid_end >= 4096)

Again, if vlan->vid_end >= 4096 is true, there is a core bug which
needs fixing.

> +		return;
> +
> +	dev_info(hellcreek->dev, "Add VLANs (%d -- %d) on port %d, %s, %s\n",
> +		 vlan->vid_begin, vlan->vid_end, port,
> +		 untagged ? "untagged" : "tagged",
> +		 pvid ? "PVID" : "no PVID");

Please go thought the driver and consider all you dev_info()
statements. Should they be dev_dbg()?

	    Andrew