Thomas, On Tue, May 13, 2014 at 6:11 PM, Thomas Abraham <ta.omasab@xxxxxxxxx> wrote: > From: Thomas Abraham <thomas.ab@xxxxxxxxxxx> > +static int exynos4210_armclk_pre_rate_change(struct clk_notifier_data *ndata, > + struct exynos_cpuclk *armclk, void __iomem *base) > +{ > + struct exynos4210_armclk_data *armclk_data = armclk->data; > + unsigned long alt_prate = clk_get_rate(armclk->alt_parent); > + unsigned long alt_div, div0, div1, tdiv0, mux_reg; > + unsigned long cur_armclk_rate, timeout; > + unsigned long flags; > + > + /* find out the divider values to use for clock data */ > + while (armclk_data->prate != ndata->new_rate) { > + if (armclk_data->prate == 0) > + return -EINVAL; > + armclk_data++; > + } > + > + div0 = armclk_data->div0; > + div1 = armclk_data->div1; > + if (readl(base + SRC_CPU) & EXYNOS4210_MUX_HPM_MASK) { > + div1 = readl(base + DIV_CPU1) & EXYNOS4210_DIV1_HPM_MASK; > + div1 |= ((armclk_data->div1) & ~EXYNOS4210_DIV1_HPM_MASK); > + } > + > + /* > + * if the new and old parent clock speed is less than the clock speed > + * of the alternate parent, then it should be ensured that at no point > + * the armclk speed is more than the old_prate until the dividers are > + * set. > + */ > + tdiv0 = readl(base + DIV_CPU0); > + cur_armclk_rate = ndata->old_rate / EXYNOS4210_ARM_DIV1(tdiv0) / > + EXYNOS4210_ARM_DIV2(tdiv0); > + if (alt_prate > cur_armclk_rate) { > + alt_div = _calc_div(alt_prate, cur_armclk_rate); > + _exynos4210_set_armclk_div(base, alt_div); > + div0 |= alt_div; Don't you need to up the voltage here, too? ...I haven't reviewed this whole patch (so perhaps it's elsewhere in the patch or in the series), but I stumbled upon this while trying to solve a different problem and figured I'd check... -Doug -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html