From b8c9c6fa2002b8fd4a9710f76f80f99c6046d48c Mon Sep 17 00:00:00 2001
From: Roger Quadros <rogerq@ti.com>
Date: Tue, 31 Oct 2017 15:26:00 +0200
Subject: [PATCH] ARM: dts: dra7: Disable USB metastability workaround for USB2
The metastability workaround causes Erratic errors [1]
on the HighSpeed USB PHY which can cause upto 2 seconds
delay in enumerating to a USB host while in Gadget mode.
Disable the Run/Stop metastability workaround to avoid this
ill effect. We are aware that this opens up the opportunity
for Run/Stop metastability, however this issue has never been
observed in TI releases so we think that Run/Stop metastability
is a lesser evil than the PHY Erratic errors. So disable it.
[1] USB controller trace during gadget enumeration
irq/90-dwc3-969 [000] d... 52.323145: dwc3_event: event
(00000901): Erratic Error [U0]
irq/90-dwc3-969 [000] d... 52.560646: dwc3_event: event
(00000901): Erratic Error [U0]
irq/90-dwc3-969 [000] d... 52.798144: dwc3_event: event
(00000901): Erratic Error [U0]
Signed-off-by: Roger Quadros <rogerq@ti.com>
Acked-by: Felipe Balbi <felipe.balbi@linux/intel.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
arch/arm/boot/dts/dra7.dtsi | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm/boot/dts/dra7.dtsi b/arch/arm/boot/dts/dra7.dtsi
index ac9216293b7c7..947ce588a35b2 100644
--- a/arch/arm/boot/dts/dra7.dtsi
+++ b/arch/arm/boot/dts/dra7.dtsi
@@ -1547,6 +1547,7 @@ usb1: usb@48890000 {
dr_mode = "otg";
snps,dis_u3_susphy_quirk;
snps,dis_u2_susphy_quirk;
+ snps,dis_metastability_quirk;
};
};
--
GitLab