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. ~Ryan -- Bluewater Systems Ltd - ARM Technology Solution Centre Ryan Mallon 5 Amuri Park, 404 Barbadoes St ryan@xxxxxxxxxxxxxxxx PO Box 13 889, Christchurch 8013 http://www.bluewatersys.com New Zealand Phone: +64 3 3779127 Freecall: Australia 1800 148 751 Fax: +64 3 3779135 USA 1800 261 2934 -- 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
