On Tue, Jun 7, 2011 at 20:12, Colin Cross <ccross@xxxxxxxxxx> wrote: >> Bootloaders should in theory setup a frequency which is enabled in >> OPP table. However, there can be mismatches, and we should try >> both going lower in addition to the going higher to find >> a match if bootloader boots up at a OPP than the kernel thinks it >> should be allowed. We also sequence the frequency and voltage settings >> properly. >> >> Reported-by: Colin Cross <ccross@xxxxxxxxxx> >> Signed-off-by: Nishanth Menon <nm@xxxxxx> >> --- >> PS: Apologies on the spam.. for some reason 10/10 never appeared in >> http://marc.info/?l=linux-omap&r=2&b=201106&w=2 - grumble grumble :( >> >> arch/arm/mach-omap2/pm.c | 55 ++++++++++++++++++++++++++++++++++++--------- >> 1 files changed, 44 insertions(+), 11 deletions(-) >> >> diff --git a/arch/arm/mach-omap2/pm.c b/arch/arm/mach-omap2/pm.c >> index 7355347..ce7554b 100644 >> --- a/arch/arm/mach-omap2/pm.c >> +++ b/arch/arm/mach-omap2/pm.c >> @@ -174,7 +174,9 @@ static int __init omap2_set_init_voltage(char *vdd_name, ch ar *clk_name, >> struct voltagedomain *voltdm; >> struct clk *clk; >> struct opp *opp; >> - unsigned long freq, bootup_volt; >> + unsigned long freq_cur, freq_valid, bootup_volt; >> + int raise_freq_idx, i; >> + int ret = -EINVAL; >> >> if (!vdd_name || !clk_name || !dev) { >> printk(KERN_ERR "%s: Invalid parameters!\n", __func__); >> @@ -195,16 +197,20 @@ static int __init omap2_set_init_voltage(char *vdd_name, char *clk_name, >> goto exit; >> } >> >> - freq = clk->rate; >> - clk_put(clk); >> + freq_cur = clk->rate; >> + freq_valid = freq_cur; >> >> rcu_read_lock(); >> - opp = opp_find_freq_ceil(dev, &freq); >> + opp = opp_find_freq_ceil(dev, &freq_valid); >> if (IS_ERR(opp)) { >> - rcu_read_unlock(); >> - printk(KERN_ERR "%s: unable to find boot up OPP for vdd_%s\n", >> - __func__, vdd_name); >> - goto exit; >> + opp = opp_find_freq_floor(dev, &freq_valid); >> + if (IS_ERR(opp)) { >> + rcu_read_unlock(); >> + pr_err("%s: no boot OPP match for %ld on vdd_%s\n", >> + __func__, freq_cur, vdd_name); >> + ret = -ENOENT; >> + goto exit_ck; >> + } >> } >> >> bootup_volt = opp_get_voltage(opp); >> @@ -212,11 +218,38 @@ static int __init omap2_set_init_voltage(char *vdd_name, char *clk_name, >> if (!bootup_volt) { >> printk(KERN_ERR "%s: unable to find voltage corresponding" >> "to the bootup OPP for vdd_%s\n", __func__, vdd_name); >> - goto exit; >> + ret = -ENOENT; >> + goto exit_ck; >> } >> >> - voltdm_scale(voltdm, bootup_volt); >> - return 0; >> + /* >> + * Frequency and Voltage have to be sequenced: if we move from >> + * a lower frequency to higher frequency, raise voltage, followed by >> + * frequency, and vice versa. we assume that the voltage at boot >> + * is the required voltage for the frequency it was set for. >> + */ >> + raise_freq_idx = freq_cur < freq_valid; >> + for (i = 0; i < 2; i++) { >> + if (i == raise_freq_idx) >> + ret = clk_set_rate(clk, freq_valid); >> + else >> + ret = voltdm_scale(voltdm, bootup_volt); >> + if (ret < 0) { >> + pr_err("%s: unable to set %s-%s(f=%ld v=%ld)on vdd%s\n", >> + __func__, >> + (i == raise_freq_idx) ? "clk" : "voltage", >> + (i == raise_freq_idx) ? clk_name : vdd_name, >> + freq_valid, bootup_volt, vdd_name); >> + goto exit_ck; >> + } >> + } > > This is way too complicated. Writing out what you mean is much more > readable, and not many more LOC: hmm.. fine with me.. > > if (freq_cur < freq_valid) { > ret = voltdm_scale(voltdm, bootup_volt); > if (ret) { > pr_err("%s: unable to set voltage-%s(f=%ld v=%ld)on vdd%s\n", > vdd_name, freq_valid, bootup_volt, vdd_name); > goto exit_ck; > } > } > optionally - if (freq_cur == freq_valid) { > ret = clk_set_rate(clk, freq_valid); > if (ret) { > pr_err("%s: unable to set clk-%s(f=%ld v=%ld)on vdd%s\n", > clk_name, freq_valid, bootup_volt, vdd_name); > goto exit_ck; > } } > > if (freq_cur > freq_valid) { since we dont really know how the bootloader might have set the voltage, (twl4030 allows i2c1 programming, others plugged on I2C_SR can either use forcedupdate/vc bypass, we should do a force setting of voltage.. if (freq_cur >= freq_valid) ? > ret = voltdm_scale(voltdm, bootup_volt); > if (ret) { > pr_err("%s: unable to set voltage-%s(f=%ld v=%ld)on vdd%s\n", > vdd_name, freq_valid, bootup_volt, vdd_name); > goto exit_ck; > } > } > >> + >> + ret = 0; >> +exit_ck: >> + clk_put(clk); >> + >> + if (!ret) >> + return 0; >> >> exit: >> printk(KERN_ERR "%s: Unable to put vdd_%s to its init voltage\n\n", >> -- >> 1.7.1 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-omap" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html > Regards, Nishanth Menon -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
