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* [PATCH] ARM: tegra: fix ulpi regression on tegra20
@ 2018-02-19 15:12 Marcel Ziswiler
  2018-04-20  8:52 ` Marc Dietrich
  0 siblings, 1 reply; 7+ messages in thread
From: Marcel Ziswiler @ 2018-02-19 15:12 UTC (permalink / raw)
  To: linux-tegra, devicetree
  Cc: Marcel Ziswiler, Thierry Reding, Jonathan Hunter, linux-kernel,
	Rob Herring, Mark Rutland, Russell King, linux-arm-kernel

From: Marcel Ziswiler <marcel.ziswiler@toradex.com>

Since commit f8f8f1d04494 ("clk: Don't touch hardware when reparenting
during registration") ULPI has been broken on Tegra20 leading to the
following error message during boot:

[    1.974698] ulpi_phy_power_on: ulpi write failed
[    1.979384] tegra-ehci c5004000.usb: Failed to power on the phy
[    1.985434] tegra-ehci: probe of c5004000.usb failed with error -110

Debugging through the changes and finally also consulting the TRM
revealed that rather than the CDEV2 clock off OSC requiring such pin
muxing actually the PLL_P_OUT4 clock is in use. It looks like so far it
just worked by chance of that one having been enabled which Stephen's
commit now changed when reparenting sclk away from pll_p_out4 leaving
that one disabled. Fix this by properly assigning the PLL_P_OUT4 clock
as the ULPI PHY clock.

Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>

---

 arch/arm/boot/dts/tegra20.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/tegra20.dtsi b/arch/arm/boot/dts/tegra20.dtsi
index 864a95872b8d..e05b6bb2599f 100644
--- a/arch/arm/boot/dts/tegra20.dtsi
+++ b/arch/arm/boot/dts/tegra20.dtsi
@@ -741,7 +741,7 @@
 		phy_type = "ulpi";
 		clocks = <&tegra_car TEGRA20_CLK_USB2>,
 			 <&tegra_car TEGRA20_CLK_PLL_U>,
-			 <&tegra_car TEGRA20_CLK_CDEV2>;
+			 <&tegra_car TEGRA20_CLK_PLL_P_OUT4>;
 		clock-names = "reg", "pll_u", "ulpi-link";
 		resets = <&tegra_car 58>, <&tegra_car 22>;
 		reset-names = "usb", "utmi-pads";
-- 
2.14.3

^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2018-04-26 11:39 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-02-19 15:12 [PATCH] ARM: tegra: fix ulpi regression on tegra20 Marcel Ziswiler
2018-04-20  8:52 ` Marc Dietrich
2018-04-20 10:50   ` Dmitry Osipenko
2018-04-23 22:05     ` Marcel Ziswiler
2018-04-24 14:38       ` Dmitry Osipenko
2018-04-26 11:39         ` Peter De Schrijver
2018-04-23 15:42   ` Marcel Ziswiler

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