* [PATCH] ARM: dts: dra7: Disable USB metastability workaround for USB2
@ 2017-10-31 13:26 Roger Quadros
2017-12-04 11:40 ` Felipe Balbi
0 siblings, 1 reply; 3+ messages in thread
From: Roger Quadros @ 2017-10-31 13:26 UTC (permalink / raw)
To: tony; +Cc: balbi, linux-usb, linux-kernel, linux-omap, Roger Quadros
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>
---
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 02a136a..1264e39 100644
--- a/arch/arm/boot/dts/dra7.dtsi
+++ b/arch/arm/boot/dts/dra7.dtsi
@@ -1540,6 +1540,7 @@
dr_mode = "otg";
snps,dis_u3_susphy_quirk;
snps,dis_u2_susphy_quirk;
+ snps,dis_metastability_quirk;
};
};
--
cheers,
-roger
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] ARM: dts: dra7: Disable USB metastability workaround for USB2
2017-10-31 13:26 [PATCH] ARM: dts: dra7: Disable USB metastability workaround for USB2 Roger Quadros
@ 2017-12-04 11:40 ` Felipe Balbi
2017-12-11 16:47 ` Tony Lindgren
0 siblings, 1 reply; 3+ messages in thread
From: Felipe Balbi @ 2017-12-04 11:40 UTC (permalink / raw)
To: Roger Quadros, tony; +Cc: linux-usb, linux-kernel, linux-omap, Roger Quadros
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Roger Quadros <rogerq@ti.com> writes:
> 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>
FWIW:
Acked-by: Felipe Balbi <felipe.balbi@linux/intel.com>
I'm taking the dwc3 counterpart to v4.16
--
balbi
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^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] ARM: dts: dra7: Disable USB metastability workaround for USB2
2017-12-04 11:40 ` Felipe Balbi
@ 2017-12-11 16:47 ` Tony Lindgren
0 siblings, 0 replies; 3+ messages in thread
From: Tony Lindgren @ 2017-12-11 16:47 UTC (permalink / raw)
To: Felipe Balbi; +Cc: Roger Quadros, linux-usb, linux-kernel, linux-omap
* Felipe Balbi <balbi@kernel.org> [171204 11:43]:
> Roger Quadros <rogerq@ti.com> writes:
>
> > 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>
>
> FWIW:
>
> Acked-by: Felipe Balbi <felipe.balbi@linux/intel.com>
>
> I'm taking the dwc3 counterpart to v4.16
OK applying this into omap-for-v4.16/dt thanks.
Tony
^ permalink raw reply [flat|nested] 3+ messages in thread
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