2024-02-01 20:42:40

by Horatiu Vultur

Subject: [PATCH net-next] net: micrel: Fix the frequency adjustments

By default lan8841's 1588 clock frequency is 125MHz. But when adjusting
the frequency, it is using the 1PPM format of the lan8814. Which is the
wrong format as lan8814 has a 1588 clock frequency of 250MHz. So then
for each 1PPM adjustment would adjust less than expected.
Therefore fix this by using the correct 1PPM format for lan8841.

Signed-off-by: Horatiu Vultur <[email protected]>
---
drivers/net/phy/micrel.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index 40bea9293ddd7..9b69735819896 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -120,6 +120,12 @@
*/
#define LAN8814_1PPM_FORMAT 17179

+/* Represents 1ppm adjustment in 2^32 format with
+ * each nsec contains 8 clock cycles.
+ * The value is calculated as following: (1/1000000)/((2^-32)/8)
+ */
+#define LAN8841_1PPM_FORMAT 34360
+
#define PTP_RX_VERSION 0x0248
#define PTP_TX_VERSION 0x0288
#define PTP_MAX_VERSION(x) (((x) & GENMASK(7, 0)) << 8)
@@ -4115,8 +4121,8 @@ static int lan8841_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
faster = false;
}

- rate = LAN8814_1PPM_FORMAT * (upper_16_bits(scaled_ppm));
- rate += (LAN8814_1PPM_FORMAT * (lower_16_bits(scaled_ppm))) >> 16;
+ rate = LAN8841_1PPM_FORMAT * (upper_16_bits(scaled_ppm));
+ rate += (LAN8841_1PPM_FORMAT * (lower_16_bits(scaled_ppm))) >> 16;

mutex_lock(&ptp_priv->ptp_lock);
phy_write_mmd(phydev, 2, LAN8841_PTP_LTC_RATE_ADJ_HI,
--
2.34.1

2024-02-03 16:33:43

by Andrew Lunn

Subject: Re: [PATCH net-next] net: micrel: Fix the frequency adjustments

On Thu, Feb 01, 2024 at 09:42:03PM +0100, Horatiu Vultur wrote:
> By default lan8841's 1588 clock frequency is 125MHz. But when adjusting
> the frequency, it is using the 1PPM format of the lan8814. Which is the
> wrong format as lan8814 has a 1588 clock frequency of 250MHz. So then
> for each 1PPM adjustment would adjust less than expected.
> Therefore fix this by using the correct 1PPM format for lan8841.
>
> Signed-off-by: Horatiu Vultur <[email protected]>

Reviewed-by: Andrew Lunn <[email protected]>

Andrew

2024-02-04 13:41:17

by patchwork-bot+netdevbpf

Subject: Re: [PATCH net-next] net: micrel: Fix the frequency adjustments

Hello:

This patch was applied to netdev/net-next.git (main)
by David S. Miller <[email protected]>:

On Thu, 1 Feb 2024 21:42:03 +0100 you wrote:
> By default lan8841's 1588 clock frequency is 125MHz. But when adjusting
> the frequency, it is using the 1PPM format of the lan8814. Which is the
> wrong format as lan8814 has a 1588 clock frequency of 250MHz. So then
> for each 1PPM adjustment would adjust less than expected.
> Therefore fix this by using the correct 1PPM format for lan8841.
>
> Signed-off-by: Horatiu Vultur <[email protected]>
>
> [...]

Here is the summary with links:
- [net-next] net: micrel: Fix the frequency adjustments
https://git.kernel.org/netdev/net-next/c/7d7bf30f031b

You are awesome, thank you!
--
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