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

Message ID 20240201204203.2691424-1-horatiu.vultur@microchip.com
State New
Headers
Series [net-next] net: micrel: Fix the frequency adjustments |

Commit Message

Horatiu Vultur Feb. 1, 2024, 8:42 p.m. UTC
  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 <horatiu.vultur@microchip.com>
---
 drivers/net/phy/micrel.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)
  

Comments

Andrew Lunn Feb. 3, 2024, 4:33 p.m. UTC | #1
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 <horatiu.vultur@microchip.com>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew
  
patchwork-bot+netdevbpf@kernel.org Feb. 4, 2024, 1:40 p.m. UTC | #2
Hello:

This patch was applied to netdev/net-next.git (main)
by David S. Miller <davem@davemloft.net>:

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 <horatiu.vultur@microchip.com>
> 
> [...]

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!
  

Patch

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,