diff mbox

[V2,1/1] ARM: dts: sunxi: Banana Pi: increase startup-delay for the GMAC PHY regulator

Message ID 1415746906-20835-2-git-send-email-merker@debian.org (mailing list archive)
State New, archived
Headers show

Commit Message

Karsten Merker Nov. 11, 2014, 11:01 p.m. UTC 
On the LeMaker Banana Pi, probing the external ethernet PHY connected
to the SoC's internal GMAC module sometimes fails. The PHY power
supply is handled via a GPIO-controlled regulator, and the existing
regulator startup-delay of 50000us is too short to make sure that the
PHY is always fully powered up when it is queried by phylib. Tests
have shown that to provide a reliable PHY detection, the startup-delay
has to be increased to at least 60000us. To have a certain safety margin
and to cater for manufacturing variations between different boards,
the delay gets set to 100000us as discussed on the linux-arm-kernel
mailinglist.

Signed-off-by: Karsten Merker <merker@debian.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
---
 arch/arm/boot/dts/sun7i-a20-bananapi.dts |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Maxime Ripard Nov. 12, 2014, 1:37 p.m. UTC | #1 
On Wed, Nov 12, 2014 at 12:01:46AM +0100, Karsten Merker wrote:
> On the LeMaker Banana Pi, probing the external ethernet PHY connected
> to the SoC's internal GMAC module sometimes fails. The PHY power
> supply is handled via a GPIO-controlled regulator, and the existing
> regulator startup-delay of 50000us is too short to make sure that the
> PHY is always fully powered up when it is queried by phylib. Tests
> have shown that to provide a reliable PHY detection, the startup-delay
> has to be increased to at least 60000us. To have a certain safety margin
> and to cater for manufacturing variations between different boards,
> the delay gets set to 100000us as discussed on the linux-arm-kernel
> mailinglist.
> 
> Signed-off-by: Karsten Merker <merker@debian.org>
> Acked-by: Hans de Goede <hdegoede@redhat.com>

Merged, thanks.

Maxime
diff mbox

Patch

diff --git a/arch/arm/boot/dts/sun7i-a20-bananapi.dts b/arch/arm/boot/dts/sun7i-a20-bananapi.dts
index 3de847d..1cf1214 100644
--- a/arch/arm/boot/dts/sun7i-a20-bananapi.dts
+++ b/arch/arm/boot/dts/sun7i-a20-bananapi.dts
@@ -207,7 +207,7 @@ 
 		regulator-name = "gmac-3v3";
 		regulator-min-microvolt = <3300000>;
 		regulator-max-microvolt = <3300000>;
-		startup-delay-us = <50000>;
+		startup-delay-us = <100000>;
 		enable-active-high;
 		gpio = <&pio 7 23 0>;
 	};