Messages in this thread | | | Date | Mon, 5 Sep 2022 15:09:55 +0200 | From | Andrew Lunn <> | Subject | Re: [PATCH v2 net-next] net: phy: micrel: Adding SQI support for lan8814 phy |
| |
On Mon, Sep 05, 2022 at 03:47:30PM +0530, Divya Koppera wrote: > Supports SQI(Signal Quality Index) for lan8814 phy, where > it has SQI index of 0-7 values and this indicator can be used > for cable integrity diagnostic and investigating other noise > sources. It is not supported for 10Mbps speed > > Signed-off-by: Divya Koppera <Divya.Koppera@microchip.com> > --- > v1 -> v2 > - Given SQI support for all pairs of wires in 1000/100 base-T phy's > uAPI may run through all instances in future. At present returning > only first instance as uAPI supports for only 1 pair. > - SQI is not supported for 10Mbps speed, handled accordingly.
I would prefer you solve the problem of returning all pairs.
I'm not sure how useful the current implementation is, especially at 100Mbps, where pair 0 could actually be the transmit pair. Does it give a sensible value in that case?
> +static int lan8814_get_sqi(struct phy_device *phydev) > +{ > + int ret, val, pair; > + int sqi_val[4]; > + > + if (phydev->speed == SPEED_10) > + return -EOPNOTSUPP; > + > + for (pair = 0; pair < 4; pair++) { > + val = lanphy_read_page_reg(phydev, 1, LAN8814_DCQ_CTRL); > + if (val < 0) > + return val; > + > + val &= ~LAN8814_DCQ_CTRL_CHANNEL_MASK; > + val |= pair; > + val |= LAN8814_DCQ_CTRL_READ_CAPTURE_; > + ret = lanphy_write_page_reg(phydev, 1, LAN8814_DCQ_CTRL, val); > + if (ret < 0) > + return ret; > + > + ret = lanphy_read_page_reg(phydev, 1, LAN8814_DCQ_SQI); > + if (ret < 0) > + return ret; > + > + sqi_val[pair] = FIELD_GET(LAN8814_DCQ_SQI_VAL_MASK, ret); > + } > + > + return *sqi_val;
How is this going to work in the future? sqi_val is on the stack. You cannot return a pointer to it. So this function is going to need modifications.
If you really want to prepare for a future implementation which could return all four, i would probably make this a helper which takes a pair number. And then have a function call it once for pair 0.
Andrew
| |