msm8916-openwrt/target/linux/generic/backport-5.15/704-14-v5.19-net-mtk_eth_soc-add-fixme-comment-for-state-speed-us.patch
Daniel Golle aab466f422 kernel: backport generic phylink validate
Backport generic phylink validate series and make use of it for
mtk_eth_soc Ethernet driver as well as mt7530 DSA driver.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
2022-08-30 13:36:28 +01:00

39 lines
1.5 KiB
Diff

From 650a49bc65df6b0e0051a8f62d7c22d95a8f350d Mon Sep 17 00:00:00 2001
From: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Date: Wed, 18 May 2022 15:55:07 +0100
Subject: [PATCH 08/12] net: mtk_eth_soc: add fixme comment for state->speed
use
Add a fixme comment for the last remaining incorrect usage of
state->speed in the mac_config() method, which is strangely in a code
path which is only run when the PHY interface mode changes.
This means if we are in RGMII mode, changes in state->speed will not
cause the INTF_MODE, TRGMII_RCK_CTRL and TRGMII_TCK_CTRL registers to
be set according to the speed, nor will the TRGPLL clock be set to the
correct value.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
drivers/net/ethernet/mediatek/mtk_eth_soc.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -374,6 +374,14 @@ static void mtk_mac_config(struct phylin
state->interface))
goto err_phy;
} else {
+ /* FIXME: this is incorrect. Not only does it
+ * use state->speed (which is not guaranteed
+ * to be correct) but it also makes use of it
+ * in a code path that will only be reachable
+ * when the PHY interface mode changes, not
+ * when the speed changes. Consequently, RGMII
+ * is probably broken.
+ */
mtk_gmac0_rgmii_adjust(mac->hw,
state->interface,
state->speed);