On 01/29, Stephen Boyd wrote: > On 01/29/15 05:31, Geert Uytterhoeven wrote: > > Hi Tomeu, Mike, > > > > On Fri, Jan 23, 2015 at 12:03 PM, Tomeu Vizoso > > <tomeu.vizoso@xxxxxxxxxxxxx> wrote: > >> --- a/drivers/clk/clk.c > >> +++ b/drivers/clk/clk.c > >> @@ -2391,25 +2543,24 @@ int __clk_get(struct clk *clk) > >> return 1; > >> } > >> > >> -static void clk_core_put(struct clk_core *core) > >> +void __clk_put(struct clk *clk) > >> { > >> struct module *owner; > >> > >> - owner = core->owner; > >> + if (!clk || WARN_ON_ONCE(IS_ERR(clk))) > >> + return; > >> > >> clk_prepare_lock(); > >> - kref_put(&core->ref, __clk_release); > >> + > >> + hlist_del(&clk->child_node); > >> + clk_core_set_rate_nolock(clk->core, clk->core->req_rate); > > At this point, clk->core->req_rate is still zero, causing > > cpg_div6_clock_round_rate() to be called with a zero "rate" parameter, > > e.g. on r8a7791: > > Hmm.. I wonder if we should assign core->req_rate to be the same as > core->rate during __clk_init()? That would make this call to > clk_core_set_rate_nolock() a nop in this case. > Here's a patch to do this ---8<---- From: Stephen Boyd <sboyd@xxxxxxxxxxxxxx> Subject: [PATCH] clk: Assign a requested rate by default We need to assign a requested rate here so that we avoid requesting a rate of 0 on clocks when we remove clock consumers. Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx> --- drivers/clk/clk.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index a29daf9edea4..8416ed1c40be 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -2142,6 +2142,7 @@ int __clk_init(struct device *dev, struct clk *clk_user) struct clk_core *orphan; struct hlist_node *tmp2; struct clk_core *clk; + unsigned long rate; if (!clk_user) return -EINVAL; @@ -2266,12 +2267,13 @@ int __clk_init(struct device *dev, struct clk *clk_user) * then rate is set to zero. */ if (clk->ops->recalc_rate) - clk->rate = clk->ops->recalc_rate(clk->hw, + rate = clk->ops->recalc_rate(clk->hw, clk_core_get_rate_nolock(clk->parent)); else if (clk->parent) - clk->rate = clk->parent->rate; + rate = clk->parent->rate; else - clk->rate = 0; + rate = 0; + clk->rate = clk->req_rate = rate; /* * walk the list of orphan clocks and reparent any that are children of -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project