On Thu, Aug 25, 2016 at 12:15:44PM -0500, Zach Brown wrote: > On Thu, Aug 25, 2016 at 11:56:55AM +0100, Mark Rutland wrote: > > On Wed, Aug 24, 2016 at 06:23:03PM -0500, Zach Brown wrote: > > > +- fake-cd: On Zynq Devices the SDHCI Controller will not work without the cd > > > + bit. When this option is set the driver will put the controller in test mode > > > + and fake the cd bit so it will function. > > > > As Lars noted, the DT should describe the HW, and the policy of how to deal > > with that should be left to the kernel. So from a DT perspective the above is > > not correct. > > > > If I understand the linked documentation, this is slightly different to typical > > uses of broken-cd in that in the absence of a card detect signal the HW will > > not be able to access the SD card at all, even if requested to. Is that correct? > > > > If so, perhaps a better option is to have the combination of broken-cd and the > > compatible string for this IP block imply that the test mode workaround is > > required. Obviously that requires a fixup to the usual broken-cd binding to > > remove the implication that polling alone must be used. > > > > Thanks, > > Mark. > > In cases where the card is non-removable then polling doesn't make sense. We have the non-removable property to describe that, so we can also look at that. > So it doesn't make sense to tie the test mode workaround into the broken-cd > property, even though I agree the nature of the defect fits under the notion > of the CD being broken. Maybe not solely on broken-cd, but I think that we dont necessarily need a new DT property. As above, broken-cd, non-removable, and the compatible string may together give the kernel enough information to choose the right thing to do. 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
