Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Andrew Halaney <ahalaney@redhat.com>
To:     linux-kernel@vger.kernel.org
Cc:     linux-arm-kernel@lists.infradead.org,
        linux-stm32@st-md-mailman.stormreply.com, netdev@vger.kernel.org,
        mcoquelin.stm32@gmail.com, pabeni@redhat.com, kuba@kernel.org,
        edumazet@google.com, davem@davemloft.net, joabreu@synopsys.com,
        alexandre.torgue@foss.st.com, peppe.cavallaro@st.com,
        bhupesh.sharma@linaro.org, vkoul@kernel.org,
        linux-arm-msm@vger.kernel.org, jsuraj@qti.qualcomm.com,
        Andrew Halaney <ahalaney@redhat.com>
Subject: [PATCH RFC/RFT net-next 3/3] net: stmmac: Use the max frequency possible for clk_ptp_ref
Date:   Tue, 11 Jul 2023 15:35:32 -0500
Message-ID: <20230711205732.364954-4-ahalaney@redhat.com>
In-Reply-To: <20230711205732.364954-1-ahalaney@redhat.com>
References: <20230711205732.364954-1-ahalaney@redhat.com>
MIME-Version: 1.0
Content-type: text/plain
Content-Transfer-Encoding: 8bit
Precedence: bulk

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

Signed-off-by: Andrew Halaney <ahalaney@redhat.com>
---
 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