Re: [PATCH] arm64: dts: rockchip: Update DWC3 modules on RK3399 SoCs

From: Robin Murphy
Date: Thu Jun 13 2019 - 13:49:30 EST


On 13/06/2019 18:20, Enric Balletbo i Serra wrote:
Hi Robin,

On 13/6/19 18:56, Robin Murphy wrote:
On 13/06/2019 17:27, Enric Balletbo i Serra wrote:
As per binding documentation [1], the DWC3 core should have the "ref",
"bus_early" and "suspend" clocks. As explained in the binding, those
clocks are required for new platforms but not for existing platforms
before commit fe8abf332b8f ("usb: dwc3: support clocks and resets for
DWC3 core").

However, as those clocks are really treated as required, this ends with
having some annoying messages when the "rockchip,rk3399-dwc3" is used:

[ÂÂÂ 1.724107] dwc3 fe800000.dwc3: Failed to get clk 'ref': -2
[ÂÂÂ 1.731893] dwc3 fe900000.dwc3: Failed to get clk 'ref': -2
[ÂÂÂ 2.495937] dwc3 fe800000.dwc3: Failed to get clk 'ref': -2
[ÂÂÂ 2.647239] dwc3 fe900000.dwc3: Failed to get clk 'ref': -2

In order to remove those annoying messages, update the DWC3 hardware
module node and add all the required clocks. With this change, both, the
glue node and the DWC3 core node, have the clocks defined, but that's
not really a problem and there isn't a side effect on do this. So, we
can get rid of the annoying get clk error messages.

Can we not just move these clocks entirely from the glue layer to the core
layer? That didn't seem to break when I tried it, although I'll admit my
'testing' was no more than booting and mounting a USB 3.0 flash drive, no
suspend or anything fancy.


AFAICT usb doesn't break, but we won't break backward compability then? (/me
still doesn't know when backward compability is really important or not)

Ah, fair point - I was imagining the glue layer's heavy-handed "turn everything on" approach potentially interfering with the core layer's ability to exert finer-grained control of the clocks it knows more about, but the "old kernel, new DT" situation might indeed be a problem. I guess that's Heiko's call in the end. Plus I'm no CCF expert so my concern might be unfounded anyway.

My own attempt to shut up these errors got sidetracked into c0c61471ef86 ("usb:
dwc3: of-simple: Convert to bulk clk API"), then apparently stalled :)


There was any off the record discussion and stalled or simply you didn't get
feedback?

More that the 3399 board got put away in a freak "tidying the kitchen" incident, and I've just had too many other things on the go since :)

Robin.


I'll take a look.

Thanks,
~ Enric

Robin.


[1] Documentation/devicetree/bindings/usb/dwc3.txt

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
---

 arch/arm64/boot/dts/rockchip/rk3399.dtsi | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm64/boot/dts/rockchip/rk3399.dtsi
b/arch/arm64/boot/dts/rockchip/rk3399.dtsi
index 196ac9b78076..a15348d185ce 100644
--- a/arch/arm64/boot/dts/rockchip/rk3399.dtsi
+++ b/arch/arm64/boot/dts/rockchip/rk3399.dtsi
@@ -414,6 +414,9 @@
ÂÂÂÂÂÂÂÂÂÂÂÂÂ compatible = "snps,dwc3";
ÂÂÂÂÂÂÂÂÂÂÂÂÂ reg = <0x0 0xfe800000 0x0 0x100000>;
ÂÂÂÂÂÂÂÂÂÂÂÂÂ interrupts = <GIC_SPI 105 IRQ_TYPE_LEVEL_HIGH 0>;
+ÂÂÂÂÂÂÂÂÂÂÂ clocks = <&cru SCLK_USB3OTG0_REF>, <&cru ACLK_USB3OTG0>,
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ <&cru SCLK_USB3OTG0_SUSPEND>;
+ÂÂÂÂÂÂÂÂÂÂÂ clock-names = "ref", "bus_early", "suspend";
ÂÂÂÂÂÂÂÂÂÂÂÂÂ dr_mode = "otg";
ÂÂÂÂÂÂÂÂÂÂÂÂÂ phys = <&u2phy0_otg>, <&tcphy0_usb3>;
ÂÂÂÂÂÂÂÂÂÂÂÂÂ phy-names = "usb2-phy", "usb3-phy";
@@ -447,6 +450,9 @@
ÂÂÂÂÂÂÂÂÂÂÂÂÂ compatible = "snps,dwc3";
ÂÂÂÂÂÂÂÂÂÂÂÂÂ reg = <0x0 0xfe900000 0x0 0x100000>;
ÂÂÂÂÂÂÂÂÂÂÂÂÂ interrupts = <GIC_SPI 110 IRQ_TYPE_LEVEL_HIGH 0>;
+ÂÂÂÂÂÂÂÂÂÂÂ clocks = <&cru SCLK_USB3OTG1_REF>, <&cru ACLK_USB3OTG1>,
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ <&cru SCLK_USB3OTG1_SUSPEND>;
+ÂÂÂÂÂÂÂÂÂÂÂ clock-names = "ref", "bus_early", "suspend";
ÂÂÂÂÂÂÂÂÂÂÂÂÂ dr_mode = "otg";
ÂÂÂÂÂÂÂÂÂÂÂÂÂ phys = <&u2phy1_otg>, <&tcphy1_usb3>;
ÂÂÂÂÂÂÂÂÂÂÂÂÂ phy-names = "usb2-phy", "usb3-phy";


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