Hi Mike, On Fri, 2016-07-08 at 16:32 -0700, Michael Turquette wrote: > Hi James, > > Quoting James Liao (2016-07-03 20:51:48) > > On Fri, 2016-07-01 at 18:21 -0700, Stephen Boyd wrote: > > > (Resending to everyone) > > > > > > On 06/22, Erin Lo wrote: > > > > From: James Liao <jamesjj.liao@xxxxxxxxxxxx> > > > > > > > > This patch fixed wrong state of parent clocks if they are registered > > > > after critical clocks. > > > > > > > > Signed-off-by: James Liao <jamesjj.liao@xxxxxxxxxxxx> > > > > Signed-off-by: Erin Lo <erin.lo@xxxxxxxxxxxx> > > > > > > It would be nice if you included the information about the > > > problem from James' previous mail. This says what it does, but > > > doesn't explain what the problem is and how it is fixing it. > > > > > > > --- > > > > drivers/clk/clk.c | 9 ++++++++- > > > > 1 file changed, 8 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c > > > > index d584004..e9f5f89 100644 > > > > --- a/drivers/clk/clk.c > > > > +++ b/drivers/clk/clk.c > > > > @@ -2388,8 +2388,15 @@ static int __clk_core_init(struct clk_core *core) > > > > hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) { > > > > struct clk_core *parent = __clk_init_parent(orphan); > > > > > > > > - if (parent) > > > > + if (parent) { > > > > clk_core_reparent(orphan, parent); > > > > + > > > > + if (orphan->prepare_count) > > > > + clk_core_prepare(parent); > > > > + > > > > + if (orphan->enable_count) > > > > + clk_core_enable(parent); > > > > + } > > > > } > > > > > > I'm pretty sure I pointed this problem out to Mike when the > > > critical clk patches were being pushed. I can't recall what the > > > plan was though to fix the problem. I'm pretty sure he said that > > > clk_core_reparent() would take care of it, but obviously it is > > > not doing that. Or perhaps it was that clk handoff should figure > > > out that the parents of a critical clk are also on and thus keep > > > them on. > > > > Hi Mike > > > > Is there any other patch to fix this issue? Or did I misuse critical > > clock flag? > > There is no fix yes. Your fix is basically correct. I was mistaken back > when I told you and Stephen that the framework already took care of > this. > > However, instead of "open coding" this solution, I would rather re-use > the __clk_set_parent_{before,after} helpers instead. Can you review/test > the following patch and let me know what you think? > > Thanks, > Mike > > > > From c0163b3f719b1e219b28ad425f94f9ef54a25a8f Mon Sep 17 00:00:00 2001 > From: Michael Turquette <mturquette@xxxxxxxxxxxx> > Date: Fri, 8 Jul 2016 16:05:22 -0700 > Subject: [PATCH] clk: migrate ref counts when orphans are reunited > > It's always nice to see families reunited, and this is equally true when > talking about parent clocks and their children. However, if the orphan > clk had a positive prepare_count or enable_count, then we would not > migrate those counts up the parent chain correctly. > > This has manifested with the recent critical clocks feature, which often > enables clocks very early, before their parents have been registered. > > Fixed by replacing the call to clk_core_reparent with calls to > __clk_set_parent_{before,after}. > > Cc: James Liao <jamesjj.liao@xxxxxxxxxxxx> > Cc: Erin Lo <erin.lo@xxxxxxxxxxxx> > Signed-off-by: Michael Turquette <mturquette@xxxxxxxxxxxx> > --- > drivers/clk/clk.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c > index 820a939fb6bb..70efe4c4e0cc 100644 > --- a/drivers/clk/clk.c > +++ b/drivers/clk/clk.c > @@ -2449,8 +2449,14 @@ static int __clk_core_init(struct clk_core *core) > hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) { > struct clk_core *parent = __clk_init_parent(orphan); > > - if (parent) > - clk_core_reparent(orphan, parent); Is it correct to remove clk_core_reparent()? It lacks __clk_recalc_accuracies() and __clk_recalc_rates(), so the new parent's rate will not propagate correctly. For example, I set vdec_sel as a critical clock. Without your patch, the result was: vdecpll 0 0 338000000 vdecpll_ck 1 1 338000000 vdec_sel 1 1 338000000 With your patch, it became: vdecpll 1 1 338000000 vdecpll_ck 1 1 0 vdec_sel 1 1 0 The prepare_count and enable_count are correct with your patch, but the rates of vdecpll_ck and vdec_sel become incorrect. Best regards, James > + /* > + * we could call __clk_set_parent, but that would result in a > + * reducant call to the .set_rate op, if it exists > + */ > + if (parent) { > + __clk_set_parent_before(orphan, parent); > + __clk_set_parent_after(orphan, parent, NULL); > + } > } > > /* -- 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