[PATCH v3 09/12] EXAMPLE CODE: usb: port: Parse pwrseq phandle from Device Tree

Stephen Boyd stephen.boyd at linaro.org
Wed Jun 1 11:16:34 PDT 2016


Quoting Peter Chen (2016-06-01 05:05:20)
> On Wed, Jun 01, 2016 at 01:57:23AM -0700, Stephen Boyd wrote:
> > Quoting Krzysztof Kozlowski (2016-06-01 01:02:18)
> > > Parse usb-pwrseq property from Device Tree to get the phandle to pwrseq
> > > device.  The pwrseq device will be used by USB hub to cycle the power
> > > before activating ports.
> > > 
> > > Signed-off-by: Krzysztof Kozlowski <k.kozlowski at samsung.com>
> > 
> > Drive by review comment.
> > 
> > I was hoping this would help me with a problem I'm having where I have a
> > hub (smsc4604) that needs to be taken out of reset before my HSIC
> > controller sends a USB reset to it, but it seems this is more about
> > doing some sort of power on sequence after enumeration?
> > 
> 
> No, you may need to do reset before enumeration, the general purpose of
> reset is eliminate unstable hardware state, and let the controller find
> the device.
> 
> Try to do it at bootloader to see if it works for you.
> 

Sorry the bootloader doesn't do this so that doesn't work for me.



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