2023-07-11 21:27:32

by Andrew Halaney

Subject: [PATCH RFC/RFT net-next 3/3] net: stmmac: Use the max frequency possible for clk_ptp_ref

Using the max frequency allows for the best PTP timestamping resolution,
so let's default to that.

Signed-off-by: Andrew Halaney <[email protected]>
---
drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index 231152ee5a32..c9a27a71a3f4 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -602,6 +602,11 @@ stmmac_probe_config_dt(struct platform_device *pdev, u8 *mac)
plat->clk_ptp_ref = NULL;
dev_info(&pdev->dev, "PTP uses main clock\n");
} else {
+ /* Get the best resolution possible */
+ rc = clk_set_rate(plat->clk_ptp_ref, ULONG_MAX);
+ if (rc)
+ dev_err(&pdev->dev,
+ "Failed to set clk_ptp_ref rate: %d\n", rc);
plat->clk_ptp_rate = clk_get_rate(plat->clk_ptp_ref);
dev_dbg(&pdev->dev, "PTP rate %d\n", plat->clk_ptp_rate);
}
--
2.41.0

2023-07-13 10:04:39

by Simon Horman

Subject: Re: [PATCH RFC/RFT net-next 3/3] net: stmmac: Use the max frequency possible for clk_ptp_ref

On Tue, Jul 11, 2023 at 03:35:32PM -0500, Andrew Halaney wrote:
> Using the max frequency allows for the best PTP timestamping resolution,
> so let's default to that.
>
> Signed-off-by: Andrew Halaney <[email protected]>

Reviewed-by: Simon Horman <[email protected]>