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Message-ID: <98d978ec-a92c-7731-bbec-af8c79641e3c@ti.com>
Date: Wed, 21 Nov 2018 15:08:41 +0530
From: Kishon Vijay Abraham I <kishon@...com>
To: Russell King - ARM Linux <linux@...linux.org.uk>
CC: <devicetree@...r.kernel.org>,
<linux-arm-kernel@...ts.infradead.org>, <netdev@...r.kernel.org>,
Andrew Lunn <andrew@...n.ch>,
Gregory Clement <gregory.clement@...tlin.com>,
Jason Cooper <jason@...edaemon.net>,
Mark Rutland <mark.rutland@....com>,
Rob Herring <robh+dt@...nel.org>,
Sebastian Hesselbarth <sebastian.hesselbarth@...il.com>,
Thomas Petazzoni <thomas.petazzoni@...e-electrons.com>,
Maxime Chevallier <maxime.chevallier@...tlin.com>
Subject: Re: [RFC PATCH 5/6] net: marvell: neta: add support for 2500base-X
Hi,
On 14/11/18 4:41 PM, Russell King - ARM Linux wrote:
> On Wed, Nov 14, 2018 at 02:18:14PM +0530, Kishon Vijay Abraham I wrote:
>> Hi,
>>
>> On 12/11/18 6:01 PM, Russell King wrote:
>>> Signed-off-by: Russell King <rmk+kernel@...linux.org.uk>
>>> ---
>>> drivers/net/ethernet/marvell/mvneta.c | 58 ++++++++++++++++++++++++++++++-----
>>> 1 file changed, 51 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
>>> index 5bfd349bf41a..7305d4cc0630 100644
>>> --- a/drivers/net/ethernet/marvell/mvneta.c
>>> +++ b/drivers/net/ethernet/marvell/mvneta.c
>>> @@ -27,6 +27,7 @@
>>> #include <linux/of_irq.h>
>>> #include <linux/of_mdio.h>
>>> #include <linux/of_net.h>
>>> +#include <linux/phy/phy.h>
>>> #include <linux/phy.h>
>>> #include <linux/phylink.h>
>>> #include <linux/platform_device.h>
>>> @@ -437,6 +438,7 @@ struct mvneta_port {
>>> struct device_node *dn;
>>> unsigned int tx_csum_limit;
>>> struct phylink *phylink;
>>> + struct phy *comphy;
>>>
>>> struct mvneta_bm *bm_priv;
>>> struct mvneta_bm_pool *pool_long;
>>> @@ -3150,6 +3152,8 @@ static void mvneta_start_dev(struct mvneta_port *pp)
>>> {
>>> int cpu;
>>>
>>> + WARN_ON(phy_power_on(pp->comphy));
>>> +
>>> mvneta_max_rx_size_set(pp, pp->pkt_size);
>>> mvneta_txq_max_tx_size_set(pp, pp->pkt_size);
>>>
>>> @@ -3212,6 +3216,8 @@ static void mvneta_stop_dev(struct mvneta_port *pp)
>>>
>>> mvneta_tx_reset(pp);
>>> mvneta_rx_reset(pp);
>>> +
>>> + WARN_ON(phy_power_off(pp->comphy));
>>> }
>>>
>>> static void mvneta_percpu_enable(void *arg)
>>> @@ -3337,6 +3343,7 @@ static int mvneta_set_mac_addr(struct net_device *dev, void *addr)
>>> static void mvneta_validate(struct net_device *ndev, unsigned long *supported,
>>> struct phylink_link_state *state)
>>> {
>>> + struct mvneta_port *pp = netdev_priv(ndev);
>>> __ETHTOOL_DECLARE_LINK_MODE_MASK(mask) = { 0, };
>>>
>>> /* We only support QSGMII, SGMII, 802.3z and RGMII modes */
>>> @@ -3357,14 +3364,14 @@ static void mvneta_validate(struct net_device *ndev, unsigned long *supported,
>>> /* Asymmetric pause is unsupported */
>>> phylink_set(mask, Pause);
>>>
>>> - /* We cannot use 1Gbps when using the 2.5G interface. */
>>> - if (state->interface == PHY_INTERFACE_MODE_2500BASEX) {
>>> - phylink_set(mask, 2500baseT_Full);
>>> - phylink_set(mask, 2500baseX_Full);
>>> - } else {
>>> + /* Half-duplex at speeds higher than 100Mbit is unsupported */
>>> + if (pp->comphy || state->interface != PHY_INTERFACE_MODE_2500BASEX) {
>>> phylink_set(mask, 1000baseT_Full);
>>> phylink_set(mask, 1000baseX_Full);
>>> }
>>> + if (pp->comphy || state->interface == PHY_INTERFACE_MODE_2500BASEX) {
>>> + phylink_set(mask, 2500baseX_Full);
>>> + }
>>>
>>> if (!phy_interface_mode_is_8023z(state->interface)) {
>>> /* 10M and 100M are only supported in non-802.3z mode */
>>> @@ -3378,6 +3385,11 @@ static void mvneta_validate(struct net_device *ndev, unsigned long *supported,
>>> __ETHTOOL_LINK_MODE_MASK_NBITS);
>>> bitmap_and(state->advertising, state->advertising, mask,
>>> __ETHTOOL_LINK_MODE_MASK_NBITS);
>>> +
>>> + /* We can only operate at 2500BaseX or 1000BaseX. If requested
>>> + * to advertise both, only report advertising at 2500BaseX.
>>> + */
>>> + phylink_helper_basex_speed(state);
>>> }
>>>
>>> static int mvneta_mac_link_state(struct net_device *ndev,
>>> @@ -3389,7 +3401,9 @@ static int mvneta_mac_link_state(struct net_device *ndev,
>>> gmac_stat = mvreg_read(pp, MVNETA_GMAC_STATUS);
>>>
>>> if (gmac_stat & MVNETA_GMAC_SPEED_1000)
>>> - state->speed = SPEED_1000;
>>> + state->speed =
>>> + state->interface == PHY_INTERFACE_MODE_2500BASEX ?
>>> + SPEED_2500 : SPEED_1000;
>>> else if (gmac_stat & MVNETA_GMAC_SPEED_100)
>>> state->speed = SPEED_100;
>>> else
>>> @@ -3504,12 +3518,32 @@ static void mvneta_mac_config(struct net_device *ndev, unsigned int mode,
>>> MVNETA_GMAC_FORCE_LINK_DOWN);
>>> }
>>>
>>> +
>>> /* When at 2.5G, the link partner can send frames with shortened
>>> * preambles.
>>> */
>>> if (state->speed == SPEED_2500)
>>> new_ctrl4 |= MVNETA_GMAC4_SHORT_PREAMBLE_ENABLE;
>>>
>>> + if (pp->comphy) {
>>> + enum phy_mode mode = PHY_MODE_INVALID;
>>> +
>>> + switch (state->interface) {
>>> + case PHY_INTERFACE_MODE_SGMII:
>>> + case PHY_INTERFACE_MODE_1000BASEX:
>>> + mode = PHY_MODE_SGMII;
>>> + break;
>>> + case PHY_INTERFACE_MODE_2500BASEX:
>>> + mode = PHY_MODE_2500SGMII;
>>> + break;
>>> + default:
>>> + break;
>>> + }
>>> +
>>> + if (mode != PHY_MODE_INVALID)
>>> + WARN_ON(phy_set_mode(pp->comphy, mode));
>>> + }
>>> +
>>> if (new_ctrl0 != gmac_ctrl0)
>>> mvreg_write(pp, MVNETA_GMAC_CTRL_0, new_ctrl0);
>>> if (new_ctrl2 != gmac_ctrl2)
>>> @@ -4411,7 +4445,7 @@ static int mvneta_port_power_up(struct mvneta_port *pp, int phy_mode)
>>> if (phy_mode == PHY_INTERFACE_MODE_QSGMII)
>>> mvreg_write(pp, MVNETA_SERDES_CFG, MVNETA_QSGMII_SERDES_PROTO);
>>> else if (phy_mode == PHY_INTERFACE_MODE_SGMII ||
>>> - phy_mode == PHY_INTERFACE_MODE_1000BASEX)
>>> + phy_interface_mode_is_8023z(phy_mode))
>>> mvreg_write(pp, MVNETA_SERDES_CFG, MVNETA_SGMII_SERDES_PROTO);
>>> else if (!phy_interface_mode_is_rgmii(phy_mode))
>>> return -EINVAL;
>>> @@ -4428,6 +4462,7 @@ static int mvneta_probe(struct platform_device *pdev)
>>> struct mvneta_port *pp;
>>> struct net_device *dev;
>>> struct phylink *phylink;
>>> + struct phy *comphy;
>>> const char *dt_mac_addr;
>>> char hw_mac_addr[ETH_ALEN];
>>> const char *mac_from;
>>> @@ -4453,6 +4488,14 @@ static int mvneta_probe(struct platform_device *pdev)
>>> goto err_free_irq;
>>> }
>>>
>>> + comphy = devm_of_phy_get(&pdev->dev, dn, NULL);
>>> + if (comphy == ERR_PTR(-EPROBE_DEFER)) {
>>> + err = -EPROBE_DEFER;
>>> + goto err_free_irq;
>>> + } else if (IS_ERR(comphy)) {
>>> + comphy = NULL;
>>> + }
>>
>> devm_phy_optional_get can be used here instead.
>
> I don't think that will work with a NULL string.
That's correct.
>
> devm_phy_optional_get() ultimately ends up calling phy_get(), which
> in this case would receive a NULL string. It will pass that NULL
> string to of_property_match_string().
There is a check for (string == NULL), even before of_property_match_string is
invoked in phy_get()
>
> of_property_match_string() will try to find the "phy-names" property,
> which will not exist, and hence will return -EINVAL.
>
> phy_get() doesn't check for error conditions, but passes this directly
> to _of_phy_get() as the index. _of_phy_get() passes that on to
> of_parse_phandle_with_args(), which will fail to find an entry with
> cur_index == -EINVAL (since it counts up from zero.) Hence,
> _of_phy_get() will return -ENODEV, thereby causing
> devm_phy_optional_get() to return NULL, even if there's a phys=
> property present.
>
> of_phy_get() and phy_get() have different behaviours when a NULL string
> is passed in - the of_phy_get() family will get the first PHY specified
> in the DT phys= property, whereas the phy_get() family of functions
> will fail.
Agreed. I'll fix this so that we have similar behavior with of_phy_get() and
phy_get().
>
> Since there is no devm_of_phy_optional_get(), that leads people down
> the path of coding that functionality at the callsites, such as in
> drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c.
Okay.
Thanks
Kishon
>
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