Hello Krzysztof, On 01/07/2017 05:52 AM, Krzysztof Kozlowski wrote: > The ethernet adapter LAN9730, after enabling in bootloader (e.g. for > tftpboot) requires reset during boot. Otherwise it won't come up. > > The schematics of Odroid U3 are detailed enough but after grabbing > knowledge also from other sources (like U-Boot) the overall design looks > like: > 1. LAN9730 is connected to HSIC0 and USB3503 to HSIC1 of EHCI controller. > 2. USB3503 comes with its own reset pin: gpx3-5. > 3. Reset pin of LAN9730 is pulled up to 3.3 V so it cannot be used. > 4. The supply of 3.3 V for LAN9730 is delivered from buck8. > 5. Buck8 state is a logical OR of registry value (through I2C command) > and ENB8 pin. The ENB8, not described in schematics, is in fact > gpa1-1. > 6. Missing or wrongly timed reset of LAN9730 might result in missing of > two devices: LAN9730 and USB3503. Without reset, LAN9730 will not > come up, if it was enabled by bootloader. > > To fix the issue use the generic power sequence driver and toggle the > ENB8 (buck8) pin. Reset duration of 500 us was chosen by experiments > (shortest working time was 400 us). This is an easiest way to fix the > long standing LAN9730 reset issue. > > Signed-off-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx> > --- Thanks for keep pushing a fix for this long standing issue. Reviewed-by: Javier Martinez Canillas <javier@xxxxxxxxxxxxxxx> Best regards, -- Javier Martinez Canillas Open Source Group Samsung Research America -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
