When the length of the cable is more than 100m and the lan8814 is
configured to run in 1000Base-T Slave then the register of the device
needs to be optimized.
Workaround this by setting the measure time to a value of 0xb. This
value can be set regardless of the configuration.
This issue is described in 'LAN8814 Silicon Errata and Data Sheet
Clarification' and according to that, this will not be corrected in a
future silicon revision.
Signed-off-by: Horatiu Vultur <[email protected]>
---
drivers/net/phy/micrel.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index 5a0cc89eaebdd..1e3b0436e161e 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -117,6 +117,10 @@
#define LAN8814_EEE_STATE 0x38
#define LAN8814_EEE_STATE_MASK2P5P BIT(10)
+#define LAN8814_PD_CONTROLS 0x9d
+#define LAN8814_PD_CONTROLS_PD_MEAS_TIME_MASK_ GENMASK(3, 0)
+#define LAN8814_PD_CONTROLS_PD_MEAS_TIME_VAL_ 0xb
+
/* Represents 1ppm adjustment in 2^32 format with
* each nsec contains 4 clock cycles.
* The value is calculated as following: (1/1000000)/((2^-32)/4)
@@ -3302,6 +3306,12 @@ static void lan8814_errata_fixes(struct phy_device *phydev)
val = lanphy_read_page_reg(phydev, 2, LAN8814_EEE_STATE);
val &= ~LAN8814_EEE_STATE_MASK2P5P;
lanphy_write_page_reg(phydev, 2, LAN8814_EEE_STATE, val);
+
+ /* Improve cable reach beyond 100m */
+ val = lanphy_read_page_reg(phydev, 1, LAN8814_PD_CONTROLS);
+ val &= ~LAN8814_PD_CONTROLS_PD_MEAS_TIME_MASK_;
+ val |= LAN8814_PD_CONTROLS_PD_MEAS_TIME_VAL_;
+ lanphy_write_page_reg(phydev, 1, LAN8814_PD_CONTROLS, val);
}
static int lan8814_probe(struct phy_device *phydev)
--
2.34.1
On 28.02.2024 07:28, Horatiu Vultur wrote:
> When the length of the cable is more than 100m and the lan8814 is
> configured to run in 1000Base-T Slave then the register of the device
> needs to be optimized.
>
> Workaround this by setting the measure time to a value of 0xb. This
> value can be set regardless of the configuration.
>
> This issue is described in 'LAN8814 Silicon Errata and Data Sheet
> Clarification' and according to that, this will not be corrected in a
> future silicon revision.
>
> Signed-off-by: Horatiu Vultur <[email protected]>
> ---
> drivers/net/phy/micrel.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
> index 5a0cc89eaebdd..1e3b0436e161e 100644
> --- a/drivers/net/phy/micrel.c
> +++ b/drivers/net/phy/micrel.c
> @@ -117,6 +117,10 @@
> #define LAN8814_EEE_STATE 0x38
> #define LAN8814_EEE_STATE_MASK2P5P BIT(10)
>
> +#define LAN8814_PD_CONTROLS 0x9d
> +#define LAN8814_PD_CONTROLS_PD_MEAS_TIME_MASK_ GENMASK(3, 0)
> +#define LAN8814_PD_CONTROLS_PD_MEAS_TIME_VAL_ 0xb
> +
> /* Represents 1ppm adjustment in 2^32 format with
> * each nsec contains 4 clock cycles.
> * The value is calculated as following: (1/1000000)/((2^-32)/4)
> @@ -3302,6 +3306,12 @@ static void lan8814_errata_fixes(struct phy_device *phydev)
> val = lanphy_read_page_reg(phydev, 2, LAN8814_EEE_STATE);
> val &= ~LAN8814_EEE_STATE_MASK2P5P;
> lanphy_write_page_reg(phydev, 2, LAN8814_EEE_STATE, val);
> +
> + /* Improve cable reach beyond 100m */
> + val = lanphy_read_page_reg(phydev, 1, LAN8814_PD_CONTROLS);
> + val &= ~LAN8814_PD_CONTROLS_PD_MEAS_TIME_MASK_;
> + val |= LAN8814_PD_CONTROLS_PD_MEAS_TIME_VAL_;
> + lanphy_write_page_reg(phydev, 1, LAN8814_PD_CONTROLS, val);
Ok, now I see that the second fix is also in lan8814_errata_fixes.
I'd suggest to split both fixes to separate functions and name them
in more descriptive way.
> }
>
> static int lan8814_probe(struct phy_device *phydev)
The 02/28/2024 11:03, Wojciech Drewek wrote:
Hi Wojciech,
>
> On 28.02.2024 07:28, Horatiu Vultur wrote:
> > When the length of the cable is more than 100m and the lan8814 is
> > configured to run in 1000Base-T Slave then the register of the device
> > needs to be optimized.
> >
> > Workaround this by setting the measure time to a value of 0xb. This
> > value can be set regardless of the configuration.
> >
> > This issue is described in 'LAN8814 Silicon Errata and Data Sheet
> > Clarification' and according to that, this will not be corrected in a
> > future silicon revision.
> >
> > Signed-off-by: Horatiu Vultur <[email protected]>
> > ---
> > drivers/net/phy/micrel.c | 10 ++++++++++
> > 1 file changed, 10 insertions(+)
> >
> > diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
> > index 5a0cc89eaebdd..1e3b0436e161e 100644
> > --- a/drivers/net/phy/micrel.c
> > +++ b/drivers/net/phy/micrel.c
> > @@ -117,6 +117,10 @@
> > #define LAN8814_EEE_STATE 0x38
> > #define LAN8814_EEE_STATE_MASK2P5P BIT(10)
> >
> > +#define LAN8814_PD_CONTROLS 0x9d
> > +#define LAN8814_PD_CONTROLS_PD_MEAS_TIME_MASK_ GENMASK(3, 0)
> > +#define LAN8814_PD_CONTROLS_PD_MEAS_TIME_VAL_ 0xb
> > +
> > /* Represents 1ppm adjustment in 2^32 format with
> > * each nsec contains 4 clock cycles.
> > * The value is calculated as following: (1/1000000)/((2^-32)/4)
> > @@ -3302,6 +3306,12 @@ static void lan8814_errata_fixes(struct phy_device *phydev)
> > val = lanphy_read_page_reg(phydev, 2, LAN8814_EEE_STATE);
> > val &= ~LAN8814_EEE_STATE_MASK2P5P;
> > lanphy_write_page_reg(phydev, 2, LAN8814_EEE_STATE, val);
> > +
> > + /* Improve cable reach beyond 100m */
> > + val = lanphy_read_page_reg(phydev, 1, LAN8814_PD_CONTROLS);
> > + val &= ~LAN8814_PD_CONTROLS_PD_MEAS_TIME_MASK_;
> > + val |= LAN8814_PD_CONTROLS_PD_MEAS_TIME_VAL_;
> > + lanphy_write_page_reg(phydev, 1, LAN8814_PD_CONTROLS, val);
>
> Ok, now I see that the second fix is also in lan8814_errata_fixes.
> I'd suggest to split both fixes to separate functions and name them
> in more descriptive way.
Yes, I can do that. Then I will create a separate function for each
errata fix and I will do the same also for future erratas.
>
> > }
> >
> > static int lan8814_probe(struct phy_device *phydev)
--
/Horatiu