[PATCH net-next, v2 3/3] net: dsa: mt7530: disable TRGMII clock at reconfigure

Ilya Lipnitskiy ilya.lipnitskiy at gmail.com
Thu Mar 11 02:09:54 GMT 2021


Disable both core and TRGMII Tx clocks prior to reconfiguring.
Previously, only the core clock was disabled, but not TRGMII Tx clock.
So disable both, then configure them, then re-enable both, for
consistency.

Reword the comment about core_write_mmd_indirect for clarity.

Tested on Ubiquiti ER-X running the GMAC and MT7530 in TRGMII mode.

Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy at gmail.com>
---
 drivers/net/dsa/mt7530.c | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 80a35caf920e..7ef5e7c23e05 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -435,15 +435,18 @@ mt7530_pad_clk_setup(struct dsa_switch *ds, phy_interface_t interface)
 		mt7530_write(priv, MT7530_TRGMII_TD_ODT(i),
 			     TD_DM_DRVP(8) | TD_DM_DRVN(8));
 
-	/* Setup core clock for MT7530 */
-	/* Disable MT7530 core clock */
-	core_clear(priv, CORE_TRGMII_GSW_CLK_CG, REG_GSWCK_EN);
-
-	/* Disable PLL, since phy_device has not yet been created
-	 * provided for phy_[read,write]_mmd_indirect is called, we
-	 * provide our own core_write_mmd_indirect to complete this
-	 * function.
+	/* Since phy_device has not yet been created and
+	 * phy_[read,write]_mmd_indirect is not available, we provide our own
+	 * core_write_mmd_indirect with core_{clear,write,set} wrappers to
+	 * complete this function.
 	 */
+
+	/* Disable MT7530 core and TRGMII Tx clocks */
+	core_clear(priv, CORE_TRGMII_GSW_CLK_CG,
+		   REG_GSWCK_EN | REG_TRGMIICK_EN);
+
+	/* Setup core clock for MT7530 */
+	/* Disable PLL */
 	core_write(priv, CORE_GSWPLL_GRP1, 0);
 
 	/* Set core clock into 500Mhz */
-- 
2.30.2




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