On Thu, 2014-03-06 at 02:31PM +0100, Mike Looijmans wrote: > On 03/04/2014 10:00 PM, Sören Brinkmann wrote: > >On Tue, 2014-03-04 at 10:06PM +0200, Eli Billauer wrote: > >>Hello Sören, > >> > >>wp-inverted solves the practical problem indeed, and fools the > >>driver into thinking that the card has an inverted write protection > >>sensor, and the logic zero that it finds in the hardware register > >>means that the card isn't write protected. > >> > >>I'm insisting on this patch, because I think that the device tree > >>should describe the hardware as it is, and not fool the driver into > >>behaving the way we want it to. These tricks always bite back later > >>on. > >Well, why is broken-wp more accurate than wp-inverted? Strictly > >speaking the WP is there and working, it's just tied off to some value > >you want to have interpreted the other way. > >Anyway, seems like this is solvable with wp-inverted and whether the > >additional quirk is needed I leave to others do decide. > > I've begged for this patch - or a similar one - to be included too, > because on our boards, the "wp" value appears to be sort of random. > Out of 5 prototype boards, 3 would only boot with wp-inverted while > the other 2 wouldn't boot with wp-inverted set. > > In our case I really don't know (and I don't care either) to which > logic level the wp happens to think it's wired. I just want to be > able to tell the driver that the WP line is > free-floating-and-might-have-any-random-value-at-any-given-moment > which is a bit long, so I'd go for disable-wp instead. Could you provide the design you use and give more details? According to the people I talked to, the signal should never float, unless you pin it out and don't drive it. Actually, you should open a support case for this. It is not supposed to happen. Sören -- 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
