On Tue, 25 Jan 2011, Ryan Mallon wrote: > On 01/25/2011 10:01 AM, Julia Lawall wrote: > > On Tue, 25 Jan 2011, Ryan Mallon wrote: > > > >> On 01/25/2011 09:28 AM, Julia Lawall wrote: > >>>> Julia is correct. Some architectures can return NULL from clk_get, but I > >>>> didn't check the at91 before posting :-/. If we can't return NULL from > >>>> clk_get then we shouldn't bother checking for it. I do think we should > >>>> drop the !IS_ERR(clk_get(dev, func)) check though. > >>> > >>> It seems a bit subtle, because the clk manipulated by clk_get in the call > >>> of clk_get(dev, func) is not necessarily the same as the one in > >>> clock_associate. But perhaps this is the only possibility in practice? > >> > >> Not sure I follow. The at91 clk_get does not modify the clk. In > >> at91_clock_associate we have: > >> > >> clk->function = func; > >> clk->dev = dev; > >> > >> and in clk_get we have: > >> > >> if (clk->function && (dev == clk->dev) && > >> strcmp(id, clk->function) == 0) > >> return clk; > >> > >> So at91_clock_associate sets the function for a clock, and clk_get > >> returns clocks based on the function association if the name lookup > >> fails. The only caveat to this is that the the clock function name > >> (clk->function) is not the same as any others clock's clk->name. > > > > Right, that was what I was worried about. That one would find the same > > information already present but somewhere else. But perhaps it can't > > happen, or it doesn't matter if it does? > > I think that users are expected to ensure that clock names and clock > function names do not overlap. One can't have a clock with a different name but the same device and function? julia -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
