| Message ID | 1509456360-2638-1-git-send-email-rogerq@ti.com |
|---|---|
| State | New |
| Headers | show |
| Series | ARM: dts: dra7: Disable USB metastability workaround for USB2 | expand |
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
* 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 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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; }; };
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(+) -- cheers, -roger Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html