On Mon, May 15, 2017 at 6:08 AM, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote: > On 12 May 2017 at 22:03, Rob Herring <robh@xxxxxxxxxx> wrote: >> On Mon, May 08, 2017 at 06:21:10PM +0200, Ulf Hansson wrote: >>> During power off, after the GPIO pin has been asserted, some devices like >>> the Wifi chip from TI, Wl18xx, needs a delay before the host continues with >>> clock gating and turning off regulators as to follow a graceful shutdown >>> sequence. >>> >>> Therefore invent an optional power-off-delay-us DT binding for >>> mmc-pwrseq-simple, to allow us to support this constraint. >> >> Do you really need this to be programmable per device. A delay is not >> going to hurt devices that don't need it. > > Well, that depends on what "hurt" means. The device would still be > properly shut down, only that it would take unnecessary longer to do > so. > > I think the problem here, is that this delay may also affect system > suspend/resume time of the device, if the device powers off/on in this > sequence. I was assuming that given you changed the units the time was small enough to not be significant. >> Sorry, but this is exactly what I don't like about "simple" bindings: >> adding one property at a time. > > I understand you opinion, which in the end is a matter of taste/flavor. It's more than that. The problem is you would end up with a different binding if everything is defined up front versus reviewing one addition at a time. To give a trivial example here, now we have power on and off times in different units and if I was reviewing them together I would say make them both usec. That example is mostly taste, but different units also makes it more error prone for the dts writer. > However, for me this just follows the existing approach - and suddenly > say no to this, doesn't really seems right either. I never said no. Rob -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
