On Thu, Jul 23, 2015 at 11:52:19AM +0100, Badola Nikhil wrote: > > -----Original Message----- > > From: Mark Rutland [mailto:mark.rutland@xxxxxxx] > > Sent: Thursday, July 23, 2015 3:27 PM > > To: Badola Nikhil-B46172 > > Cc: linux-kernel@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; balbi@xxxxxx > > Subject: Re: [PATCH 1/3] Documentation: dt: dwc3: Add snps,configure-fladj > > property > > > > On Thu, Jul 23, 2015 at 11:09:21AM +0100, Nikhil Badola wrote: > > > Add property snps,configure-fladj for enabling post silicon frame > > > length adjustment > > > > > > Signed-off-by: Nikhil Badola <nikhil.badola@xxxxxxxxxxxxx> > > > --- > > > Documentation/devicetree/bindings/usb/dwc3.txt | 1 + > > > 1 file changed, 1 insertion(+) > > > > > > diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt > > > b/Documentation/devicetree/bindings/usb/dwc3.txt > > > index 0815eac..90c3972 100644 > > > --- a/Documentation/devicetree/bindings/usb/dwc3.txt > > > +++ b/Documentation/devicetree/bindings/usb/dwc3.txt > > > @@ -40,6 +40,7 @@ Optional properties: > > > - snps,hird-threshold: HIRD threshold > > > - snps,hsphy_interface: High-Speed PHY interface selection between > > "utmi" for > > > UTMI+ and "ulpi" for ULPI when the DWC_USB3_HSPHY_INTERFACE has > > value 3. > > > + - snps,configure-fladj: enables post-silicon frame length adjustment > > > > Could you elaborate on what this means and why you think it's necessary? > > This property enables the use of GFLADJ_30MHZ field value of gfladj register for frame length > adjustment instead of considering from the sideband input signal fladj_30mhz_reg from SOC. > This is required when signal fladj_30mhz_reg is connected to a wrong value or is not valid as > in our case, hence post-silicon. Ok, so this is basically an override for the GFLADJ_30MHZ field of the gfladj register when there was a problem at integration time. > However this field can be used to adjust any offset ranging from 00h to 3Fh, from the > clock source generating SOF(start of frame) packets. Thus, this property can be added to device > tree with appropriate adjustment value. It takes a value? The description above makes it sound like a boolean property. I'd expect a description more like: - snps,fladj-override: Value for GFLADJ_30MHZ when the fladj_30mhz_reg signal is invalid or incorrect. Which makes it clear what the value is and when it should be set. Thanks, Mark. -- 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
