Messages in this thread | | | Date | Thu, 22 Apr 2010 13:56:23 +0200 | From | Sascha Hauer <> | Subject | Re: [PATCH] arm: mxc: utilise usecount field in clock operations |
| |
On Wed, Apr 21, 2010 at 09:37:31PM +0300, Amit Kucheria wrote: > clk->usecount can be used by platform code to check if a clock is active or > not.
The patch seems mostly fine but the commit log not. How about something like 'This patch fixes the clock refcounting when reparenting is used.'
A reference to
http://www.spinics.net/lists/arm-kernel/msg85879.html
might help aswell.
> > Signed-off-by: Amit Kucheria <amit.kucheria@canonical.com> > --- > arch/arm/plat-mxc/clock.c | 37 ++++++++++++++++++++++++------------- > 1 files changed, 24 insertions(+), 13 deletions(-) > > diff --git a/arch/arm/plat-mxc/clock.c b/arch/arm/plat-mxc/clock.c > index 323ff8c..c791f38 100644 > --- a/arch/arm/plat-mxc/clock.c > +++ b/arch/arm/plat-mxc/clock.c > @@ -50,15 +50,15 @@ static DEFINE_MUTEX(clocks_mutex); > > static void __clk_disable(struct clk *clk) > { > - if (clk == NULL || IS_ERR(clk)) > + if (clk == NULL || IS_ERR(clk) || !clk->usecount) > return; > > - __clk_disable(clk->parent); > - __clk_disable(clk->secondary); > - > - WARN_ON(!clk->usecount); > - if (!(--clk->usecount) && clk->disable) > - clk->disable(clk); > + if (!(--clk->usecount)) { > + if (clk->disable) > + clk->disable(clk); > + __clk_disable(clk->parent); > + __clk_disable(clk->secondary); > + } > } > > static int __clk_enable(struct clk *clk) > @@ -66,12 +66,13 @@ static int __clk_enable(struct clk *clk) > if (clk == NULL || IS_ERR(clk)) > return -EINVAL; > > - __clk_enable(clk->parent); > - __clk_enable(clk->secondary); > - > - if (clk->usecount++ == 0 && clk->enable) > - clk->enable(clk); > + if (clk->usecount++ == 0) { > + __clk_enable(clk->parent); > + __clk_enable(clk->secondary); > > + if (clk->enable) > + clk->enable(clk); > + } > return 0; > } > > @@ -160,17 +161,27 @@ EXPORT_SYMBOL(clk_set_rate); > int clk_set_parent(struct clk *clk, struct clk *parent) > { > int ret = -EINVAL; > + struct clk *prev_parent = clk->parent; > > if (clk == NULL || IS_ERR(clk) || parent == NULL || > IS_ERR(parent) || clk->set_parent == NULL) > return ret; > > + if (clk->usecount != 0) { > + clk_enable(parent); > + } > + > mutex_lock(&clocks_mutex); > ret = clk->set_parent(clk, parent); > - if (ret == 0) > + if (ret == 0) { > clk->parent = parent; > + }
Please remove this hunk. It does not change anything except violating the coding style. Also, please remove unnecessary braces.
> mutex_unlock(&clocks_mutex); > > + if (clk->usecount != 0) { > + clk_disable(prev_parent); > + } > + > return ret; > } > EXPORT_SYMBOL(clk_set_parent); > -- > 1.7.0.4 > >
-- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
| |