On 2015년 11월 19일 19:10, MyungJoo Ham wrote: >> After probing the devfreq device driver, the value of both min_freq and >> max_freq are zero(0). So, this patch initializes the 'min_freq' and >> 'max_freq' >> field of devfreq device by using the freq_table array. >> >> Signed-off-by: Chanwoo Choi <cw00.c...@samsung.com> >> --- >> drivers/devfreq/devfreq.c | 5 +++++ >> 1 file changed, 5 insertions(+) >> >> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c >> index c292ceb7ff19..0b24ae7b7a48 100644 >> --- a/drivers/devfreq/devfreq.c >> +++ b/drivers/devfreq/devfreq.c >> @@ -121,6 +121,11 @@ static void devfreq_set_freq_table(struct devfreq >> *devfreq) >> profile->freq_table[i] = freq; >> } >> rcu_read_unlock(); >> + >> + mutex_lock(&devfreq->lock); >> + devfreq->min_freq = profile->freq_table[0]; >> + devfreq->max_freq = profile->freq_table[profile->max_state - 1]; >> + mutex_unlock(&devfreq->lock); >> } > > No, you should not do this. > > It is allowed to use devfreq without both OPP and freq_table > assuming that the devfreq device may operate with very many > frequencies so that practically, we can virtually give it > any frequency numbers in a given range. > (cases where profile->max_state is 0 and it is not an error) > > The value 0 is used for min/max_freq to declare > that min/max_freq is deactivated. Therefore, it is not > required to do so; they are not intended to show the hardware > configuration as well.
This case consider the devfreq device using OPP because devfreq_set_freq_table() get the number of OPP entry in OPP list before setting the min_freq/max_freq. If the devfreq device don't use the OPP entry, devfreq_set_freq_table() will return without any operation. IMHO, when devfreq device uses the OPP table including the frequency, min_freq/max_freq should show the correct value as CPUFREQ framework. Regards, Chanwoo CHoi -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
