>From: Lin Huang <[email protected]> > >Because dmc may also access the PMU_BUS_IDLE_REQ register, we need to >ensure that the pd driver and the dmc driver will not access at this >register at the same time. > >Signed-off-by: Lin Huang <[email protected]> >Signed-off-by: Enric Balletbo i Serra <[email protected]> >--- > > drivers/devfreq/rk3399_dmc.c | 47 +---------------------- > drivers/soc/rockchip/pm_domains.c | 31 +++++++++++++++ > include/soc/rockchip/rk3399_dmc.h | 63 +++++++++++++++++++++++++++++++ > 3 files changed, 96 insertions(+), 45 deletions(-) > create mode 100644 include/soc/rockchip/rk3399_dmc.h > >diff --git a/drivers/devfreq/rk3399_dmc.c b/drivers/devfreq/rk3399_dmc.c >index 5bfca028eaaf..a1f320634d69 100644 >--- a/drivers/devfreq/rk3399_dmc.c >+++ b/drivers/devfreq/rk3399_dmc.c [] >diff --git a/drivers/soc/rockchip/pm_domains.c >b/drivers/soc/rockchip/pm_domains.c >index 53efc386b1ad..7acc836e7eb7 100644 >--- a/drivers/soc/rockchip/pm_domains.c >+++ b/drivers/soc/rockchip/pm_domains.c [] >+static int dmc_notify(struct notifier_block *nb, unsigned long event, >+ void *data) >+{ >+ if (event == DEVFREQ_PRECHANGE) >+ mutex_lock(&dmc_pmu->mutex); >+ else if (event == DEVFREQ_POSTCHANGE) >+ mutex_unlock(&dmc_pmu->mutex); >+ >+ return NOTIFY_OK; >+} >+
Doesn't this incur a deadlock? 1. devfreq.c:update_freq calls devfreq_notify_transition(DEVFREQ_PRECHANGE) 2. pm_domain.c:dmc_notify calls mutex_lock(dmc_pmu->mutex) 3. devfreq.c:update_freq calls target callback 4. rk3399_dmc.c:rk3399_dmcfreq_target calls mutex_lock(&dmcfreq->lock) >>>>>> update_freq cannot proceed. <<<< Cheers, MyungJoo
