On Fri, Feb 13, 2015 at 04:35:36PM +0200, Tomi Valkeinen wrote: > On 12/02/15 15:41, Sascha Hauer wrote: > > > Tomis patch is based on the assumption that clk_set_rate(clk_round_rate(rate)) > > is equal to clk_round_rate(rate). So when this assumption is wrong then > > it should simply be reverted. > > When is it not equal? > > I agree that doing clk_set_rate(clk, clk_round_rate(clk, rate)) is > pointless, but shouldn't it still work? > > And we can forget about clk_round_rate. Without my patch, this would > behave oddly also: > > rate = clk_get_rate(clk); > clk_set_rate(clk, rate); > > The end result could be something else than 'rate'. I agree that it's a bit odd, but I think it has to be like this. Consider that you request a rate of 100Hz, but the clock can only produce 99.5Hz, so due to rounding clk_round_rate() returns 99Hz. Now when you request 99Hz from clk_set_rate() the 99.5Hz value can't be used because it's too high. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
