Skip to contentSkip to conversation

net: mdio: mux-meson-gxl: set reversed bit when using internal phy

PATCH Applied Da Xue 6 participants 6 messages Apr 25, 2025 – Apr 29, 2025

Subsystems (5)
Networking Network drivers Stable branch Arm/Amlogic Meson SoC support +1 more subsystems
lore
Share & tools
lore

Da Xue

author
#0 lore raw

PATCH v3 1/1 net: mdio: mux-meson-gxl: set reversed bit when using internal phy

This bit is necessary to receive packets from the internal PHY. Without this bit set, no activity occurs on the interface.

Normally u-boot sets this bit, but if u-boot is compiled without net support, the interface will be up but without any activity.

The vendor SDK sets this bit along with the PHY_ID bits.

Fixes 9a24e1ff4326 ("net: mdio: add amlogic gxl mdio mux support");
Signed-off-by Da Xue <[email protected]>

---
Changes since v2:
* Rename REG2_RESERVED_28 to REG2_REVERSED

Link to v2:
https://patchwork.kernel.org/project/linux-amlogic/patch/[email protected]/

---
 drivers/net/mdio/mdio-mux-meson-gxl.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
drivers/net/mdio/mdio-mux-meson-gxl.c +2 -1
index 00c66240136b..3dd12a8c8b03 100644
@@ -17,6 +17,7 @@
 #define  REG2_LEDACT		GENMASK(23, 22)
 #define  REG2_LEDLINK		GENMASK(25, 24)
 #define  REG2_DIV4SEL		BIT(27)
+#define  REG2_REVERSED		BIT(28)
 #define  REG2_ADCBYPASS		BIT(30)
 #define  REG2_CLKINSEL		BIT(31)
 #define ETH_REG3		0x4

@@ -65,7 +66,7 @@ static void gxl_enable_internal_mdio(struct gxl_mdio_mux *priv)
 	 * The only constraint is that it must match the one in
 	 * drivers/net/phy/meson-gxl.c to properly match the PHY.
 	 */
-	writel(FIELD_PREP(REG2_PHYID, EPHY_GXL_ID),
+	writel(REG2_REVERSED | FIELD_PREP(REG2_PHYID, EPHY_GXL_ID),
 	       priv->regs + ETH_REG2);
 
 	/* Enable the internal phy */
Signature · 1 line
2.39.5
build bot
#1 lore raw
FYI: kernel test robot notices the stable kernel rule is not satisfied.

Hi,

Thanks for your patch.

FYI: kernel test robot notices the stable kernel rule is not satisfied.

The check is based on https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html#option-1

Rule: add the tag "Cc: [email protected]" in the sign-off area to have the patch automatically included in the stable tree.
Subject: [PATCH v3] net: mdio: mux-meson-gxl: set reversed bit when using internal phy

Link https://lore.kernel.org/stable/20250425192009.1439508-1-da%40libre.computer open here
Signature · 2 lines
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
reviewer
#2 lore raw
In reply to Da Xue
Quoted 7 lines · Da Xue

This bit is necessary to receive packets from the internal PHY. Without this bit set, no activity occurs on the interface.

Normally u-boot sets this bit, but if u-boot is compiled without net support, the interface will be up but without any activity.

The vendor SDK sets this bit along with the PHY_ID bits.

I'd like to clarify that:
Without this patch the writel the patch is modifying will clear the PHY_ID bit. But despite that the system works if at some point (uboot) set the PHY_ID bit?

Quoted 2 lines
Fixes 9a24e1ff4326 ("net: mdio: add amlogic gxl mdio mux support");

I don't think you need to resend because of this, but the correct syntax is as follows. (No trailing ';'.)

Fixes 9a24e1ff4326 ("net: mdio: add amlogic gxl mdio mux support")
Quoted 7 lines
Signed-off-by Da Xue <[email protected]>

---
Changes since v2:
* Rename REG2_RESERVED_28 to REG2_REVERSED

Link to v2:
https://patchwork.kernel.org/project/linux-amlogic/patch/[email protected]/

...

#3 lore raw
Quoted 5 lines · Simon Horman
Quoted 3 lines · Da Xue

This bit is necessary to receive packets from the internal PHY. Without this bit set, no activity occurs on the interface.

Quoted 8 lines
Quoted 4 lines

Normally u-boot sets this bit, but if u-boot is compiled without net support, the interface will be up but without any activity.

The vendor SDK sets this bit along with the PHY_ID bits.

I'd like to clarify that:
Without this patch the writel the patch is modifying will clear the PHY_ID bit. But despite that the system works if at some point (uboot) set the PHY_ID bit?

Correct. If this is set once, it will work until the IP is powered down or reset.
If u-boot does not set it, Linux will not set it and the IP will not work. If u-boot does set it, the IP will not work after suspend-resume since the IP is reset.
Thus, we need to set it on the Linux side when bringing up the interface.

Quoted 6 lines
Quoted 3 lines
Fixes 9a24e1ff4326 ("net: mdio: add amlogic gxl mdio mux support");

I don't think you need to resend because of this, but the correct syntax is as follows. (No trailing ';'.)

Great and thanks! I just set up git send-email so I'm a little rough around the edges.

Quoted 17 lines
Fixes 9a24e1ff4326 ("net: mdio: add amlogic gxl mdio mux support")
Quoted 7 lines
Signed-off-by Da Xue <[email protected]>

---
Changes since v2:
* Rename REG2_RESERVED_28 to REG2_REVERSED

Link to v2:
https://patchwork.kernel.org/project/linux-amlogic/patch/[email protected]/

...

_______________________________________________
linux-amlogic mailing list
[email protected]
http://lists.infradead.org/mailman/listinfo/linux-amlogic

maintainer
#4 lore raw
Quoted 13 lines · On Mon, 28 Apr 2025 20:44:14 -0400 Da Xue wrote:
Quoted 12 lines · Da Xue
Quoted 7 lines

This bit is necessary to receive packets from the internal PHY. Without this bit set, no activity occurs on the interface.

Normally u-boot sets this bit, but if u-boot is compiled without net support, the interface will be up but without any activity.

The vendor SDK sets this bit along with the PHY_ID bits.

I'd like to clarify that:
Without this patch the writel the patch is modifying will clear the PHY_ID bit. But despite that the system works if at some point (uboot) set the PHY_ID bit?

Quoted 6 lines

Correct. If this is set once, it will work until the IP is powered down or reset.
If u-boot does not set it, Linux will not set it and the IP will not work. If u-boot does set it, the IP will not work after suspend-resume since the IP is reset.
Thus, we need to set it on the Linux side when bringing up the interface.

Added to the commit message when applying, thank you both!

CI Applied
#5 lore raw
In reply to Da Xue
This patch was applied to netdev/net.git (main) by Jakub Kicinski <[email protected]>:

Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <[email protected]>:

Quoted 9 lines · On Fri, 25 Apr 2025 15:20:09 -0400 you wrote:

This bit is necessary to receive packets from the internal PHY. Without this bit set, no activity occurs on the interface.

Normally u-boot sets this bit, but if u-boot is compiled without net support, the interface will be up but without any activity.

The vendor SDK sets this bit along with the PHY_ID bits.

[...]

Here is the summary with links:
- [v3] net: mdio: mux-meson-gxl: set reversed bit when using internal phy

    https://git.kernel.org/netdev/net/c/b23285e93bef

You are awesome, thank you!

Signature · 2 lines
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html